Literature Review

A long-term brain imaging study in aging adults showed faster rates of atrophy in certain brain structures to be associated with the risk of developing mild cognitive impairment (MCI).

While some brain atrophy is expected in aging, high levels of atrophy in the white matter and high enlargement in the ventricles are associated with earlier progression from normal cognition to MCI, the study found. The researchers also identified diabetes and atypical levels of amyloid beta protein in the cerebrospinal fluid as risk factors for brain atrophy and MCI.

For their research, published online on JAMA Network Open, Yuto Uchida, MD, PhD, and his colleagues at the Johns Hopkins University School of Medicine in Baltimore, Maryland, looked at data for 185 individuals (mean age, 55.4 years; 63% women) who were cognitively normal at baseline and followed for a median of 20 years.

All had been enrolled in a longitudinal cohort study on biomarkers of cognitive decline conducted at Johns Hopkins. Each participant underwent a median of five structural MRI studies during the follow-up period as well as annual cognitive testing. Altogether 60 individuals developed MCI, with eight of them progressing to dementia.

“We hypothesized that annual rates of change of segmental brain volumes would be associated with vascular risk factors among middle-aged and older adults and that these trends would be associated with the progression from normal cognition to MCI,” Uchida and colleagues wrote.
 

Uniquely Long Follow-Up

Most longitudinal studies using structural MRI count a decade or less of follow-up, the study authors noted. This makes it difficult to discern whether the annual rates of change of brain volumes are affected by vascular risk factors or are useful in predicting MCI, they said. Individual differences in brain aging make population-based studies less informative.

This study’s long timeframe allowed for tracking of brain changes “on an individual basis, which facilitates the differentiation between interindividual and intraindividual variations and leads to more accurate estimations of rates of brain atrophy,” Uchida and colleagues wrote.

People with high levels of atrophy in the white matter and enlargement in the ventricles saw earlier progression to MCI (hazard ratio [HR], 1.86; 95% CI, 1.24-2.49; P = .001). Diabetes mellitus was associated with progression to MCI (HR, 1.41; 95% CI, 1.06-1.76; P = .04), as was a low CSF Abeta42:Abeta40 ratio (HR, 1.48; 95% CI, 1.09-1.88; P = .04).

People with both diabetes and an abnormal amyloid profile were even more vulnerable to developing MCI (HR, 1.55; 95% CI, 1.13-1.98; P = .03). This indicated “a synergic association of diabetes and amyloid pathology with MCI progression,” Uchida and colleagues wrote, noting that insulin resistance has been shown to promote the formation of amyloid plaques, a hallmark of Alzheimer’s disease.

The findings also underscore that “white matter volume changes are closely associated with cognitive function in aging, suggesting that white matter degeneration may play a crucial role in cognitive decline,” the authors noted.

Uchida and colleagues acknowledged the modest size and imbalanced sex ratio of their study cohort as potential weaknesses, as well as the fact that the imaging technologies had changed over the course of the study. Most of the participants were White with family histories of dementia.
 

Findings May Lead to Targeted Interventions

In an editorial comment accompanying Uchida and colleagues’ study, Shohei Fujita, MD, PhD, of Massachusetts General Hospital, Boston, said that, while a more diverse population sample would be desirable and should be sought for future studies, the results nonetheless highlight “the potential of long-term longitudinal brain MRI datasets in elucidating the interplay of risk factors underlying cognitive decline and the potential benefits of controlling diabetes to reduce the risk of progression” along the Alzheimer’s disease continuum.

The findings may prove informative, Fujita said, in developing “targeted interventions for those most susceptible to progressive brain changes, potentially combining lifestyle modifications and pharmacological treatments.”

Uchida and colleagues’ study was funded by the Alzheimer’s Association, the National Alzheimer’s Coordinating Center, and the National Institutes of Health. The study’s corresponding author, Kenichi Oishi, disclosed funding from the Richman Family Foundation, Richman, the Sharp Family Foundation, and others. Uchida and Fujita reported no relevant financial conflicts of interest.

A version of this article first appeared on Medscape.com.

A long-term brain imaging study in aging adults showed faster rates of atrophy in certain brain structures to be associated with the risk of developing mild cognitive impairment (MCI).

While some brain atrophy is expected in aging, high levels of atrophy in the white matter and high enlargement in the ventricles are associated with earlier progression from normal cognition to MCI, the study found. The researchers also identified diabetes and atypical levels of amyloid beta protein in the cerebrospinal fluid as risk factors for brain atrophy and MCI.

For their research, published online on JAMA Network Open, Yuto Uchida, MD, PhD, and his colleagues at the Johns Hopkins University School of Medicine in Baltimore, Maryland, looked at data for 185 individuals (mean age, 55.4 years; 63% women) who were cognitively normal at baseline and followed for a median of 20 years.

All had been enrolled in a longitudinal cohort study on biomarkers of cognitive decline conducted at Johns Hopkins. Each participant underwent a median of five structural MRI studies during the follow-up period as well as annual cognitive testing. Altogether 60 individuals developed MCI, with eight of them progressing to dementia.

“We hypothesized that annual rates of change of segmental brain volumes would be associated with vascular risk factors among middle-aged and older adults and that these trends would be associated with the progression from normal cognition to MCI,” Uchida and colleagues wrote.
 

Uniquely Long Follow-Up

Most longitudinal studies using structural MRI count a decade or less of follow-up, the study authors noted. This makes it difficult to discern whether the annual rates of change of brain volumes are affected by vascular risk factors or are useful in predicting MCI, they said. Individual differences in brain aging make population-based studies less informative.

This study’s long timeframe allowed for tracking of brain changes “on an individual basis, which facilitates the differentiation between interindividual and intraindividual variations and leads to more accurate estimations of rates of brain atrophy,” Uchida and colleagues wrote.

People with high levels of atrophy in the white matter and enlargement in the ventricles saw earlier progression to MCI (hazard ratio [HR], 1.86; 95% CI, 1.24-2.49; P = .001). Diabetes mellitus was associated with progression to MCI (HR, 1.41; 95% CI, 1.06-1.76; P = .04), as was a low CSF Abeta42:Abeta40 ratio (HR, 1.48; 95% CI, 1.09-1.88; P = .04).

People with both diabetes and an abnormal amyloid profile were even more vulnerable to developing MCI (HR, 1.55; 95% CI, 1.13-1.98; P = .03). This indicated “a synergic association of diabetes and amyloid pathology with MCI progression,” Uchida and colleagues wrote, noting that insulin resistance has been shown to promote the formation of amyloid plaques, a hallmark of Alzheimer’s disease.

The findings also underscore that “white matter volume changes are closely associated with cognitive function in aging, suggesting that white matter degeneration may play a crucial role in cognitive decline,” the authors noted.

Uchida and colleagues acknowledged the modest size and imbalanced sex ratio of their study cohort as potential weaknesses, as well as the fact that the imaging technologies had changed over the course of the study. Most of the participants were White with family histories of dementia.
 

Findings May Lead to Targeted Interventions

In an editorial comment accompanying Uchida and colleagues’ study, Shohei Fujita, MD, PhD, of Massachusetts General Hospital, Boston, said that, while a more diverse population sample would be desirable and should be sought for future studies, the results nonetheless highlight “the potential of long-term longitudinal brain MRI datasets in elucidating the interplay of risk factors underlying cognitive decline and the potential benefits of controlling diabetes to reduce the risk of progression” along the Alzheimer’s disease continuum.

The findings may prove informative, Fujita said, in developing “targeted interventions for those most susceptible to progressive brain changes, potentially combining lifestyle modifications and pharmacological treatments.”

Uchida and colleagues’ study was funded by the Alzheimer’s Association, the National Alzheimer’s Coordinating Center, and the National Institutes of Health. The study’s corresponding author, Kenichi Oishi, disclosed funding from the Richman Family Foundation, Richman, the Sharp Family Foundation, and others. Uchida and Fujita reported no relevant financial conflicts of interest.

A version of this article first appeared on Medscape.com.

A long-term brain imaging study in aging adults showed faster rates of atrophy in certain brain structures to be associated with the risk of developing mild cognitive impairment (MCI).

While some brain atrophy is expected in aging, high levels of atrophy in the white matter and high enlargement in the ventricles are associated with earlier progression from normal cognition to MCI, the study found. The researchers also identified diabetes and atypical levels of amyloid beta protein in the cerebrospinal fluid as risk factors for brain atrophy and MCI.

For their research, published online on JAMA Network Open, Yuto Uchida, MD, PhD, and his colleagues at the Johns Hopkins University School of Medicine in Baltimore, Maryland, looked at data for 185 individuals (mean age, 55.4 years; 63% women) who were cognitively normal at baseline and followed for a median of 20 years.

All had been enrolled in a longitudinal cohort study on biomarkers of cognitive decline conducted at Johns Hopkins. Each participant underwent a median of five structural MRI studies during the follow-up period as well as annual cognitive testing. Altogether 60 individuals developed MCI, with eight of them progressing to dementia.

“We hypothesized that annual rates of change of segmental brain volumes would be associated with vascular risk factors among middle-aged and older adults and that these trends would be associated with the progression from normal cognition to MCI,” Uchida and colleagues wrote.
 

Uniquely Long Follow-Up

Most longitudinal studies using structural MRI count a decade or less of follow-up, the study authors noted. This makes it difficult to discern whether the annual rates of change of brain volumes are affected by vascular risk factors or are useful in predicting MCI, they said. Individual differences in brain aging make population-based studies less informative.

This study’s long timeframe allowed for tracking of brain changes “on an individual basis, which facilitates the differentiation between interindividual and intraindividual variations and leads to more accurate estimations of rates of brain atrophy,” Uchida and colleagues wrote.

People with high levels of atrophy in the white matter and enlargement in the ventricles saw earlier progression to MCI (hazard ratio [HR], 1.86; 95% CI, 1.24-2.49; P = .001). Diabetes mellitus was associated with progression to MCI (HR, 1.41; 95% CI, 1.06-1.76; P = .04), as was a low CSF Abeta42:Abeta40 ratio (HR, 1.48; 95% CI, 1.09-1.88; P = .04).

People with both diabetes and an abnormal amyloid profile were even more vulnerable to developing MCI (HR, 1.55; 95% CI, 1.13-1.98; P = .03). This indicated “a synergic association of diabetes and amyloid pathology with MCI progression,” Uchida and colleagues wrote, noting that insulin resistance has been shown to promote the formation of amyloid plaques, a hallmark of Alzheimer’s disease.

The findings also underscore that “white matter volume changes are closely associated with cognitive function in aging, suggesting that white matter degeneration may play a crucial role in cognitive decline,” the authors noted.

Uchida and colleagues acknowledged the modest size and imbalanced sex ratio of their study cohort as potential weaknesses, as well as the fact that the imaging technologies had changed over the course of the study. Most of the participants were White with family histories of dementia.
 

Findings May Lead to Targeted Interventions

In an editorial comment accompanying Uchida and colleagues’ study, Shohei Fujita, MD, PhD, of Massachusetts General Hospital, Boston, said that, while a more diverse population sample would be desirable and should be sought for future studies, the results nonetheless highlight “the potential of long-term longitudinal brain MRI datasets in elucidating the interplay of risk factors underlying cognitive decline and the potential benefits of controlling diabetes to reduce the risk of progression” along the Alzheimer’s disease continuum.

The findings may prove informative, Fujita said, in developing “targeted interventions for those most susceptible to progressive brain changes, potentially combining lifestyle modifications and pharmacological treatments.”

Uchida and colleagues’ study was funded by the Alzheimer’s Association, the National Alzheimer’s Coordinating Center, and the National Institutes of Health. The study’s corresponding author, Kenichi Oishi, disclosed funding from the Richman Family Foundation, Richman, the Sharp Family Foundation, and others. Uchida and Fujita reported no relevant financial conflicts of interest.

A version of this article first appeared on Medscape.com.

A group of international experts is challenging revised diagnostic criteria for Alzheimer’s disease as laid out by the Alzheimer’s Association earlier in 2024.

In a paper published online in JAMA Neurology, the International Working Group (IWG), which includes 46 experts from 17 countries, is recommending that the diagnosis of Alzheimer’s disease be limited to individuals with mild cognitive impairment or dementia and not be applied to cognitively normal individuals with Alzheimer’s disease biomarkers such as amyloid-beta 42/40 or p-tau.

Clinicians should be “very careful” about using the “A” word (Alzheimer’s) for cognitively unimpaired people with Alzheimer’s disease biomarkers, said the paper’s first author Bruno Dubois, MD, professor of neurology, Sorbonne University and Department of Neurology, Pitié-Salpêtrière Hospital, Paris, France.

Providing an Alzheimer’s disease diagnosis to those who have a high chance of never developing cognitive impairment can be psychologically harmful, said Dubois.

“It’s not something small like telling someone they have a fever. Just imagine you’re 65 years old and are amyloid positive, and you’re told you have Alzheimer’s disease. It affects the decisions you make for the rest of your life and changes your vision of your future, even though you may never develop the disease,” he added.
 

Divergent View

The IWG’s perspective on Alzheimer’s disease contrasts with a recent proposal from the Alzheimer’s Association. The Alzheimer’s Association criteria suggest that Alzheimer’s disease should be regarded solely as a biological entity, which could include cognitively normal individuals with one core Alzheimer’s disease biomarker.

The IWG noted that its concerns regarding the application of a purely biological definition of Alzheimer’s disease in clinical practice prompted the group to consider updating its guidelines, potentially offering “an alternative definitional view of Alzheimer’s disease as a clinical-biological construct for clinical use.”

The group conducted a PubMed search for relevant Alzheimer’s disease articles, and included references, published between July 2020 and March 2024. The research showed the majority of biomarker-positive, cognitively normal individuals will not become symptomatic during their lifetime.

The risk of a 55-year-old who is amyloid positive developing Alzheimer’s disease is not that much higher than that for an individual of a similar age who is amyloid negative, Dubois noted. “There’s an 83% chance that person will never develop Alzheimer’s disease.”

Disclosing a diagnosis of Alzheimer’s disease to cognitively normal people with only one core Alzheimer’s disease biomarker represents “the most problematic implication of a purely biological definition of the disease,” the authors noted.

“A biomarker is a marker of pathology, not a biomarker of disease,” said Dubois, adding that a person may have markers for several different brain diseases.

The IWG recommends the following nomenclature: At risk for Alzheimer’s disease for those with Alzheimer’s disease biomarkers but low lifetime risk and presymptomatic Alzheimer’s disease for those with Alzheimer’s disease biomarkers with a very high lifetime risk for progression such as individuals with autosomal dominant genetic mutations and other distinct biomarker profiles that put them at extremely high lifetime risk of developing the disease.

Dubois emphasized the difference between those showing typical Alzheimer’s disease symptoms with positive biomarkers who should be considered to have the disease and those with positive biomarkers but no typical Alzheimer’s disease symptoms who should be considered at risk.

This is an important distinction as it affects research approaches and assessment of risks, he said.

For low-risk asymptomatic individuals, the IWG does not recommend routine diagnostic testing outside of the research setting. “There’s no reason to send a 65-year-old cognitively normal subject off to collect biomarker information,” said Dubois.

He reiterated the importance of clinicians using appropriate and sensitive language surrounding Alzheimer’s disease when face to face with patients. This issue “is not purely semantic; this is real life.”

For these patients in the clinical setting, “we have to be very careful about proposing treatments that may have side effects,” he said.

However, this does not mean asymptomatic at-risk people should not be studied to determine what pharmacological interventions might prevent or delay the onset of clinical disease, he noted.

Presymptomatic individuals who are at a high risk of developing Alzheimer’s disease “should be the target for clinical trials in the future” to determine best ways to delay the conversion to Alzheimer’s disease, he said.

The main focus of such research should be to better understand the “biomarker pattern profile” that is associated with a high risk of developing Alzheimer’s disease, said Dubois.
 

Plea for Unity

In an accompanying editorial, Ronald C. Petersen, PhD, MD, director, Mayo Clinic Alzheimer’s Disease Research Center and Mayo Clinic Study of Aging, Rochester, Minnesota, and colleagues outline the difference between the IWG and Alzheimer’s Association positions.

As the IWG uses Alzheimer’s disease to define those with cognitive impairment and the Alzheimer’s Association group uses Alzheimer’s disease to define those with the pathology of the disease, the field is now at a crossroads. “Do we name the disease before clinical symptoms?” they asked.

They note that Alzheimer’s Association criteria distinguish between a disease and an illness, whereas the IWG does not. “As such, although the primary disagreement between the groups is semantic, the ramifications of the labeling can be significant.”

It is “incumbent” that the field “come together” on an Alzheimer’s disease definition, the editorial concluded. “Neither the Alzheimer’s Association or IWG documents are appropriate to serve as a guide for how to apply biomarkers in a clinical setting. Appropriate-use criteria are needed to form a bridge between biological frameworks and real-world clinical practice so we can all maximally help all of our patients with this disorder.”

In a comment, Reisa Sperling, MD, professor of neurology, Harvard Medical School, and director, Center for Alzheimer Research and Treatment, Brigham and Women’s Hospital and Massachusetts General Hospital, all in Boston, who is part of the Alzheimer’s Association work group that published the revised criteria for diagnosis and staging of Alzheimer’s disease, likened Alzheimer’s disease, which begins in the brain many years before dementia onset, to cardiovascular disease in that it involves multiple processes. She noted the World Health Organization classifies cardiovascular disease as a “disease” prior to clinical manifestations such as stroke and myocardial infarction.

“If someone has Alzheimer’s disease pathology in their brain, they are at risk for dementia or clinical manifestations of the disease — just like vascular disease quantifies the risk of stroke or heart attack, not risk of developing ‘vascular disease’ if the underlying vascular disease is already present,” said Sperling.

A large part of the controversy is related to terminology and the “stigma” of the “A” word in the same way there used to be fear around using the “C” word — cancer, said Sperling.

“Once people began talking about cancer publicly as a potentially treatable disease and began getting screened and diagnosed before symptoms of cancer were manifest, this has had a tremendous impact on public health.”

She clarified that her work group does not recommend screening asymptomatic people with Alzheimer’s disease biomarkers. “We actually need to prove that treating at the preclinical stage of the disease is able to prevent clinical impairment and dementia,” she said, adding “hopefully, we are getting closer to this.”

Dubois reported no relevant disclosures. Petersen reported receiving personal fees from Roche, Genentech, Eli Lilly and Company, Eisai, and Novo Nordisk outside the submitted work and royalties from Oxford University Press, UpToDate, and Medscape educational activities.

A version of this article appeared on Medscape.com.

A group of international experts is challenging revised diagnostic criteria for Alzheimer’s disease as laid out by the Alzheimer’s Association earlier in 2024.

In a paper published online in JAMA Neurology, the International Working Group (IWG), which includes 46 experts from 17 countries, is recommending that the diagnosis of Alzheimer’s disease be limited to individuals with mild cognitive impairment or dementia and not be applied to cognitively normal individuals with Alzheimer’s disease biomarkers such as amyloid-beta 42/40 or p-tau.

Clinicians should be “very careful” about using the “A” word (Alzheimer’s) for cognitively unimpaired people with Alzheimer’s disease biomarkers, said the paper’s first author Bruno Dubois, MD, professor of neurology, Sorbonne University and Department of Neurology, Pitié-Salpêtrière Hospital, Paris, France.

Providing an Alzheimer’s disease diagnosis to those who have a high chance of never developing cognitive impairment can be psychologically harmful, said Dubois.

“It’s not something small like telling someone they have a fever. Just imagine you’re 65 years old and are amyloid positive, and you’re told you have Alzheimer’s disease. It affects the decisions you make for the rest of your life and changes your vision of your future, even though you may never develop the disease,” he added.
 

Divergent View

The IWG’s perspective on Alzheimer’s disease contrasts with a recent proposal from the Alzheimer’s Association. The Alzheimer’s Association criteria suggest that Alzheimer’s disease should be regarded solely as a biological entity, which could include cognitively normal individuals with one core Alzheimer’s disease biomarker.

The IWG noted that its concerns regarding the application of a purely biological definition of Alzheimer’s disease in clinical practice prompted the group to consider updating its guidelines, potentially offering “an alternative definitional view of Alzheimer’s disease as a clinical-biological construct for clinical use.”

The group conducted a PubMed search for relevant Alzheimer’s disease articles, and included references, published between July 2020 and March 2024. The research showed the majority of biomarker-positive, cognitively normal individuals will not become symptomatic during their lifetime.

The risk of a 55-year-old who is amyloid positive developing Alzheimer’s disease is not that much higher than that for an individual of a similar age who is amyloid negative, Dubois noted. “There’s an 83% chance that person will never develop Alzheimer’s disease.”

Disclosing a diagnosis of Alzheimer’s disease to cognitively normal people with only one core Alzheimer’s disease biomarker represents “the most problematic implication of a purely biological definition of the disease,” the authors noted.

“A biomarker is a marker of pathology, not a biomarker of disease,” said Dubois, adding that a person may have markers for several different brain diseases.

The IWG recommends the following nomenclature: At risk for Alzheimer’s disease for those with Alzheimer’s disease biomarkers but low lifetime risk and presymptomatic Alzheimer’s disease for those with Alzheimer’s disease biomarkers with a very high lifetime risk for progression such as individuals with autosomal dominant genetic mutations and other distinct biomarker profiles that put them at extremely high lifetime risk of developing the disease.

Dubois emphasized the difference between those showing typical Alzheimer’s disease symptoms with positive biomarkers who should be considered to have the disease and those with positive biomarkers but no typical Alzheimer’s disease symptoms who should be considered at risk.

This is an important distinction as it affects research approaches and assessment of risks, he said.

For low-risk asymptomatic individuals, the IWG does not recommend routine diagnostic testing outside of the research setting. “There’s no reason to send a 65-year-old cognitively normal subject off to collect biomarker information,” said Dubois.

He reiterated the importance of clinicians using appropriate and sensitive language surrounding Alzheimer’s disease when face to face with patients. This issue “is not purely semantic; this is real life.”

For these patients in the clinical setting, “we have to be very careful about proposing treatments that may have side effects,” he said.

However, this does not mean asymptomatic at-risk people should not be studied to determine what pharmacological interventions might prevent or delay the onset of clinical disease, he noted.

Presymptomatic individuals who are at a high risk of developing Alzheimer’s disease “should be the target for clinical trials in the future” to determine best ways to delay the conversion to Alzheimer’s disease, he said.

The main focus of such research should be to better understand the “biomarker pattern profile” that is associated with a high risk of developing Alzheimer’s disease, said Dubois.
 

Plea for Unity

In an accompanying editorial, Ronald C. Petersen, PhD, MD, director, Mayo Clinic Alzheimer’s Disease Research Center and Mayo Clinic Study of Aging, Rochester, Minnesota, and colleagues outline the difference between the IWG and Alzheimer’s Association positions.

As the IWG uses Alzheimer’s disease to define those with cognitive impairment and the Alzheimer’s Association group uses Alzheimer’s disease to define those with the pathology of the disease, the field is now at a crossroads. “Do we name the disease before clinical symptoms?” they asked.

They note that Alzheimer’s Association criteria distinguish between a disease and an illness, whereas the IWG does not. “As such, although the primary disagreement between the groups is semantic, the ramifications of the labeling can be significant.”

It is “incumbent” that the field “come together” on an Alzheimer’s disease definition, the editorial concluded. “Neither the Alzheimer’s Association or IWG documents are appropriate to serve as a guide for how to apply biomarkers in a clinical setting. Appropriate-use criteria are needed to form a bridge between biological frameworks and real-world clinical practice so we can all maximally help all of our patients with this disorder.”

In a comment, Reisa Sperling, MD, professor of neurology, Harvard Medical School, and director, Center for Alzheimer Research and Treatment, Brigham and Women’s Hospital and Massachusetts General Hospital, all in Boston, who is part of the Alzheimer’s Association work group that published the revised criteria for diagnosis and staging of Alzheimer’s disease, likened Alzheimer’s disease, which begins in the brain many years before dementia onset, to cardiovascular disease in that it involves multiple processes. She noted the World Health Organization classifies cardiovascular disease as a “disease” prior to clinical manifestations such as stroke and myocardial infarction.

“If someone has Alzheimer’s disease pathology in their brain, they are at risk for dementia or clinical manifestations of the disease — just like vascular disease quantifies the risk of stroke or heart attack, not risk of developing ‘vascular disease’ if the underlying vascular disease is already present,” said Sperling.

A large part of the controversy is related to terminology and the “stigma” of the “A” word in the same way there used to be fear around using the “C” word — cancer, said Sperling.

“Once people began talking about cancer publicly as a potentially treatable disease and began getting screened and diagnosed before symptoms of cancer were manifest, this has had a tremendous impact on public health.”

She clarified that her work group does not recommend screening asymptomatic people with Alzheimer’s disease biomarkers. “We actually need to prove that treating at the preclinical stage of the disease is able to prevent clinical impairment and dementia,” she said, adding “hopefully, we are getting closer to this.”

Dubois reported no relevant disclosures. Petersen reported receiving personal fees from Roche, Genentech, Eli Lilly and Company, Eisai, and Novo Nordisk outside the submitted work and royalties from Oxford University Press, UpToDate, and Medscape educational activities.

A version of this article appeared on Medscape.com.

A group of international experts is challenging revised diagnostic criteria for Alzheimer’s disease as laid out by the Alzheimer’s Association earlier in 2024.

In a paper published online in JAMA Neurology, the International Working Group (IWG), which includes 46 experts from 17 countries, is recommending that the diagnosis of Alzheimer’s disease be limited to individuals with mild cognitive impairment or dementia and not be applied to cognitively normal individuals with Alzheimer’s disease biomarkers such as amyloid-beta 42/40 or p-tau.

Clinicians should be “very careful” about using the “A” word (Alzheimer’s) for cognitively unimpaired people with Alzheimer’s disease biomarkers, said the paper’s first author Bruno Dubois, MD, professor of neurology, Sorbonne University and Department of Neurology, Pitié-Salpêtrière Hospital, Paris, France.

Providing an Alzheimer’s disease diagnosis to those who have a high chance of never developing cognitive impairment can be psychologically harmful, said Dubois.

“It’s not something small like telling someone they have a fever. Just imagine you’re 65 years old and are amyloid positive, and you’re told you have Alzheimer’s disease. It affects the decisions you make for the rest of your life and changes your vision of your future, even though you may never develop the disease,” he added.
 

Divergent View

The IWG’s perspective on Alzheimer’s disease contrasts with a recent proposal from the Alzheimer’s Association. The Alzheimer’s Association criteria suggest that Alzheimer’s disease should be regarded solely as a biological entity, which could include cognitively normal individuals with one core Alzheimer’s disease biomarker.

The IWG noted that its concerns regarding the application of a purely biological definition of Alzheimer’s disease in clinical practice prompted the group to consider updating its guidelines, potentially offering “an alternative definitional view of Alzheimer’s disease as a clinical-biological construct for clinical use.”

The group conducted a PubMed search for relevant Alzheimer’s disease articles, and included references, published between July 2020 and March 2024. The research showed the majority of biomarker-positive, cognitively normal individuals will not become symptomatic during their lifetime.

The risk of a 55-year-old who is amyloid positive developing Alzheimer’s disease is not that much higher than that for an individual of a similar age who is amyloid negative, Dubois noted. “There’s an 83% chance that person will never develop Alzheimer’s disease.”

Disclosing a diagnosis of Alzheimer’s disease to cognitively normal people with only one core Alzheimer’s disease biomarker represents “the most problematic implication of a purely biological definition of the disease,” the authors noted.

“A biomarker is a marker of pathology, not a biomarker of disease,” said Dubois, adding that a person may have markers for several different brain diseases.

The IWG recommends the following nomenclature: At risk for Alzheimer’s disease for those with Alzheimer’s disease biomarkers but low lifetime risk and presymptomatic Alzheimer’s disease for those with Alzheimer’s disease biomarkers with a very high lifetime risk for progression such as individuals with autosomal dominant genetic mutations and other distinct biomarker profiles that put them at extremely high lifetime risk of developing the disease.

Dubois emphasized the difference between those showing typical Alzheimer’s disease symptoms with positive biomarkers who should be considered to have the disease and those with positive biomarkers but no typical Alzheimer’s disease symptoms who should be considered at risk.

This is an important distinction as it affects research approaches and assessment of risks, he said.

For low-risk asymptomatic individuals, the IWG does not recommend routine diagnostic testing outside of the research setting. “There’s no reason to send a 65-year-old cognitively normal subject off to collect biomarker information,” said Dubois.

He reiterated the importance of clinicians using appropriate and sensitive language surrounding Alzheimer’s disease when face to face with patients. This issue “is not purely semantic; this is real life.”

For these patients in the clinical setting, “we have to be very careful about proposing treatments that may have side effects,” he said.

However, this does not mean asymptomatic at-risk people should not be studied to determine what pharmacological interventions might prevent or delay the onset of clinical disease, he noted.

Presymptomatic individuals who are at a high risk of developing Alzheimer’s disease “should be the target for clinical trials in the future” to determine best ways to delay the conversion to Alzheimer’s disease, he said.

The main focus of such research should be to better understand the “biomarker pattern profile” that is associated with a high risk of developing Alzheimer’s disease, said Dubois.
 

Plea for Unity

In an accompanying editorial, Ronald C. Petersen, PhD, MD, director, Mayo Clinic Alzheimer’s Disease Research Center and Mayo Clinic Study of Aging, Rochester, Minnesota, and colleagues outline the difference between the IWG and Alzheimer’s Association positions.

As the IWG uses Alzheimer’s disease to define those with cognitive impairment and the Alzheimer’s Association group uses Alzheimer’s disease to define those with the pathology of the disease, the field is now at a crossroads. “Do we name the disease before clinical symptoms?” they asked.

They note that Alzheimer’s Association criteria distinguish between a disease and an illness, whereas the IWG does not. “As such, although the primary disagreement between the groups is semantic, the ramifications of the labeling can be significant.”

It is “incumbent” that the field “come together” on an Alzheimer’s disease definition, the editorial concluded. “Neither the Alzheimer’s Association or IWG documents are appropriate to serve as a guide for how to apply biomarkers in a clinical setting. Appropriate-use criteria are needed to form a bridge between biological frameworks and real-world clinical practice so we can all maximally help all of our patients with this disorder.”

In a comment, Reisa Sperling, MD, professor of neurology, Harvard Medical School, and director, Center for Alzheimer Research and Treatment, Brigham and Women’s Hospital and Massachusetts General Hospital, all in Boston, who is part of the Alzheimer’s Association work group that published the revised criteria for diagnosis and staging of Alzheimer’s disease, likened Alzheimer’s disease, which begins in the brain many years before dementia onset, to cardiovascular disease in that it involves multiple processes. She noted the World Health Organization classifies cardiovascular disease as a “disease” prior to clinical manifestations such as stroke and myocardial infarction.

“If someone has Alzheimer’s disease pathology in their brain, they are at risk for dementia or clinical manifestations of the disease — just like vascular disease quantifies the risk of stroke or heart attack, not risk of developing ‘vascular disease’ if the underlying vascular disease is already present,” said Sperling.

A large part of the controversy is related to terminology and the “stigma” of the “A” word in the same way there used to be fear around using the “C” word — cancer, said Sperling.

“Once people began talking about cancer publicly as a potentially treatable disease and began getting screened and diagnosed before symptoms of cancer were manifest, this has had a tremendous impact on public health.”

She clarified that her work group does not recommend screening asymptomatic people with Alzheimer’s disease biomarkers. “We actually need to prove that treating at the preclinical stage of the disease is able to prevent clinical impairment and dementia,” she said, adding “hopefully, we are getting closer to this.”

Dubois reported no relevant disclosures. Petersen reported receiving personal fees from Roche, Genentech, Eli Lilly and Company, Eisai, and Novo Nordisk outside the submitted work and royalties from Oxford University Press, UpToDate, and Medscape educational activities.

A version of this article appeared on Medscape.com.

A growing body of research explores the link between stroke risk and regular consumption of coffee, tea, soda, and alcohol. This research roundup reviews the latest findings, highlighting both promising insights and remaining uncertainties to help guide discussions with your patients.

Coffee and Tea: Good or Bad? 

In the INTERSTROKE study, high coffee consumption (> 4 cups daily) was associated with an significantly increased risk for all strokes (odds ratio [OR], 1.37) or ischemic stroke (OR, 1.31), while low to moderate coffee had no link to increased stroke risk. In contrast, tea consumption was associated with lower odds of all stroke (OR, 0.81 for highest intake) or ischemic stroke (OR, 0.81). 

In a recent UK Biobank study, consumption of coffee or tea was associated with reduced risk for stroke and dementia, with the biggest benefit associated with consuming both beverages. 

Specifically, the investigators found that individuals who drank two to three cups of coffee and two to three cups of tea per day had a 30% decrease in incidence of stroke and a 28% lower risk for dementia versus those who did not.

A recent systematic review and dose-response meta-analysis showed that each daily cup increase in tea was associated with an average 4% reduced risk for stroke and a 2% reduced risk for cardiovascular disease (CVD) events. 

The protective effect of coffee and tea on stroke risk may be driven, in part, by flavonoids, which have antioxidant and anti-inflammatory properties, as well as positive effects on vascular function.

“The advice to patients should be that coffee and tea may protect against stroke, but that sweetening either beverage with sugar probably should be minimized,” said Cheryl Bushnell, MD, MHS, of Wake Forest University School of Medicine in Winston-Salem, North Carolina, and chair of the American Stroke Association (ASA) 2024 Guideline for the Primary Prevention of Stroke. 

Taylor Wallace, PhD, a certified food scientist, said, “most people should consume a cup or two of unsweetened tea per day in moderation for cardiometabolic health. It is an easy step in the right direction for good health but not a cure-all.”

When it comes to coffee, adults who like it should drink it “in moderation — just lay off the cream and sugar,” said Wallace, adjunct associate professor at George Washington University, Washington, DC, and Tufts University, Boston, Massachusetts.

“A cup or two of black coffee with low-fat or nonfat milk with breakfast is a healthy way to start the day, especially when you’re like me and have an 8-year-old that is full of energy!” Wallace said. 
 

The Skinny on Soda

When it comes to sugar-sweetened and diet beverages, data from the Nurses’ Health Study and Health Professionals Follow-Up Study, showed a 16% increased risk for stroke with one or more daily servings of sugar-sweetened or low-calorie soda per day (vs none), independent of established dietary and nondietary cardiovascular risk factors. 

In the Women’s Health Initiative Observational Study of postmenopausal women, a higher intake of artificially sweetened beverages was associated with increased risk for all stroke (adjusted hazard ratio [aHR], 1.23), ischemic stroke (aHR, 1.31), coronary heart disease (aHR, 1.29) and all-cause mortality (aHR, 1.16).

In the Framingham Heart Study Offspring cohort, consumption of one can of diet soda or more each day (vs none) was associated with a nearly threefold increased risk for stroke and dementia over a 10-year follow-up period. 

A separate French study showed that total artificial sweetener intake from all sources was associated with increased overall risk for cardiovascular and cerebrovascular disease.

However, given the limitations of these studies, it’s hard to draw any firm conclusions, Wallace cautioned. 

“We know that sugar-sweetened beverages are correlated with weight gain and cardiometabolic dysfunction promotion in children and adults,” he said. 

Yet, “there really isn’t any convincing evidence that diet soda has much impact on human health at all. Most observational studies are mixed and likely very confounded by other diet and lifestyle factors. That doesn’t mean go overboard; a daily diet soda is probably fine, but that doesn’t mean go drink 10 of them every day,” he added. 
 

Alcohol: Moderation or Abstinence?

Evidence on alcohol use and stroke risk have been mixed over the years. For decades, the evidence was suggestive that a moderate amount of alcohol daily (one to two drinks in men and one drink in women) may be beneficial at reducing major vascular outcomes.

Yet, over the past few years, some research has found no evidence of benefit with moderate alcohol intake. And the detrimental effects of excessive alcohol use are clear. 

A large meta-analysis showed that light to moderate alcohol consumption (up to one drink per day) was associated with a reduced risk for ischemic stroke. However, heavy drinking (more than two drinks per day) significantly increased the risk for both ischemic and hemorrhagic stroke.

A separate study showed young adults who are moderate to heavy drinkers are at increased risk for stroke — and the risk increases with more years of imbibing.

In the INTERSTROKE study, high to moderate alcohol consumption was associated with increased stroke risk, whereas low alcohol consumption conferred no increased risk. 

However, Bushnell pointed out that the study data was derived from based on self-report, and that other healthy behaviors may counteract the risk for alcohol consumption.

“For alcohol, regardless of stroke risk, the most important data shows that any alcohol consumption is associated with worse cognitive function, so generally, the lower the alcohol consumption the better,” Bushnell said. 

She noted that, currently, the American Heart Association (AHA)/ASA recommend a maximum of two drinks per day for men and one drink per day for women to reduce stroke risk.

“However, the data for the risk for cognitive impairment with any alcohol is convincing and should be kept in mind in addition to the maximum alcohol recommended by the AHA/ASA,” Bushnell advised. 

“We know excessive intake puts you at major risk for CVD, cancer, cognitive decline, and a whole host of other health ailments — no question there,” said Wallace.

The impact of moderate intake, on the other hand, is less clear. “Alcohol is a highly biased and political issue and the evidence (or lack thereof) on both sides is shoddy at best,” Wallace added.

A key challenge is that accurate self-reporting of alcohol intake is difficult, even for scientists, and most studies rely on self-reported data from observational cohorts. These often include limited dietary assessments, which provide only a partial picture of long-term consumption patterns, Wallace noted. 

“The short answer is we don’t know if moderation is beneficial, detrimental, or null with respect to health,” he said.

Bushnell reports no relevant disclosures. Wallace (www.drtaylorwallace.com) is CEO of Think Healthy Group; editor of The Journal of Dietary Supplements, deputy editor of The Journal of the American Nutrition Association (www.nutrition.org), nutrition section editor of Annals of Medicine, and an advisory board member with Forbes Health.

A version of this article appeared on Medscape.com.

A growing body of research explores the link between stroke risk and regular consumption of coffee, tea, soda, and alcohol. This research roundup reviews the latest findings, highlighting both promising insights and remaining uncertainties to help guide discussions with your patients.

Coffee and Tea: Good or Bad? 

In the INTERSTROKE study, high coffee consumption (> 4 cups daily) was associated with an significantly increased risk for all strokes (odds ratio [OR], 1.37) or ischemic stroke (OR, 1.31), while low to moderate coffee had no link to increased stroke risk. In contrast, tea consumption was associated with lower odds of all stroke (OR, 0.81 for highest intake) or ischemic stroke (OR, 0.81). 

In a recent UK Biobank study, consumption of coffee or tea was associated with reduced risk for stroke and dementia, with the biggest benefit associated with consuming both beverages. 

Specifically, the investigators found that individuals who drank two to three cups of coffee and two to three cups of tea per day had a 30% decrease in incidence of stroke and a 28% lower risk for dementia versus those who did not.

A recent systematic review and dose-response meta-analysis showed that each daily cup increase in tea was associated with an average 4% reduced risk for stroke and a 2% reduced risk for cardiovascular disease (CVD) events. 

The protective effect of coffee and tea on stroke risk may be driven, in part, by flavonoids, which have antioxidant and anti-inflammatory properties, as well as positive effects on vascular function.

“The advice to patients should be that coffee and tea may protect against stroke, but that sweetening either beverage with sugar probably should be minimized,” said Cheryl Bushnell, MD, MHS, of Wake Forest University School of Medicine in Winston-Salem, North Carolina, and chair of the American Stroke Association (ASA) 2024 Guideline for the Primary Prevention of Stroke. 

Taylor Wallace, PhD, a certified food scientist, said, “most people should consume a cup or two of unsweetened tea per day in moderation for cardiometabolic health. It is an easy step in the right direction for good health but not a cure-all.”

When it comes to coffee, adults who like it should drink it “in moderation — just lay off the cream and sugar,” said Wallace, adjunct associate professor at George Washington University, Washington, DC, and Tufts University, Boston, Massachusetts.

“A cup or two of black coffee with low-fat or nonfat milk with breakfast is a healthy way to start the day, especially when you’re like me and have an 8-year-old that is full of energy!” Wallace said. 
 

The Skinny on Soda

When it comes to sugar-sweetened and diet beverages, data from the Nurses’ Health Study and Health Professionals Follow-Up Study, showed a 16% increased risk for stroke with one or more daily servings of sugar-sweetened or low-calorie soda per day (vs none), independent of established dietary and nondietary cardiovascular risk factors. 

In the Women’s Health Initiative Observational Study of postmenopausal women, a higher intake of artificially sweetened beverages was associated with increased risk for all stroke (adjusted hazard ratio [aHR], 1.23), ischemic stroke (aHR, 1.31), coronary heart disease (aHR, 1.29) and all-cause mortality (aHR, 1.16).

In the Framingham Heart Study Offspring cohort, consumption of one can of diet soda or more each day (vs none) was associated with a nearly threefold increased risk for stroke and dementia over a 10-year follow-up period. 

A separate French study showed that total artificial sweetener intake from all sources was associated with increased overall risk for cardiovascular and cerebrovascular disease.

However, given the limitations of these studies, it’s hard to draw any firm conclusions, Wallace cautioned. 

“We know that sugar-sweetened beverages are correlated with weight gain and cardiometabolic dysfunction promotion in children and adults,” he said. 

Yet, “there really isn’t any convincing evidence that diet soda has much impact on human health at all. Most observational studies are mixed and likely very confounded by other diet and lifestyle factors. That doesn’t mean go overboard; a daily diet soda is probably fine, but that doesn’t mean go drink 10 of them every day,” he added. 
 

Alcohol: Moderation or Abstinence?

Evidence on alcohol use and stroke risk have been mixed over the years. For decades, the evidence was suggestive that a moderate amount of alcohol daily (one to two drinks in men and one drink in women) may be beneficial at reducing major vascular outcomes.

Yet, over the past few years, some research has found no evidence of benefit with moderate alcohol intake. And the detrimental effects of excessive alcohol use are clear. 

A large meta-analysis showed that light to moderate alcohol consumption (up to one drink per day) was associated with a reduced risk for ischemic stroke. However, heavy drinking (more than two drinks per day) significantly increased the risk for both ischemic and hemorrhagic stroke.

A separate study showed young adults who are moderate to heavy drinkers are at increased risk for stroke — and the risk increases with more years of imbibing.

In the INTERSTROKE study, high to moderate alcohol consumption was associated with increased stroke risk, whereas low alcohol consumption conferred no increased risk. 

However, Bushnell pointed out that the study data was derived from based on self-report, and that other healthy behaviors may counteract the risk for alcohol consumption.

“For alcohol, regardless of stroke risk, the most important data shows that any alcohol consumption is associated with worse cognitive function, so generally, the lower the alcohol consumption the better,” Bushnell said. 

She noted that, currently, the American Heart Association (AHA)/ASA recommend a maximum of two drinks per day for men and one drink per day for women to reduce stroke risk.

“However, the data for the risk for cognitive impairment with any alcohol is convincing and should be kept in mind in addition to the maximum alcohol recommended by the AHA/ASA,” Bushnell advised. 

“We know excessive intake puts you at major risk for CVD, cancer, cognitive decline, and a whole host of other health ailments — no question there,” said Wallace.

The impact of moderate intake, on the other hand, is less clear. “Alcohol is a highly biased and political issue and the evidence (or lack thereof) on both sides is shoddy at best,” Wallace added.

A key challenge is that accurate self-reporting of alcohol intake is difficult, even for scientists, and most studies rely on self-reported data from observational cohorts. These often include limited dietary assessments, which provide only a partial picture of long-term consumption patterns, Wallace noted. 

“The short answer is we don’t know if moderation is beneficial, detrimental, or null with respect to health,” he said.

Bushnell reports no relevant disclosures. Wallace (www.drtaylorwallace.com) is CEO of Think Healthy Group; editor of The Journal of Dietary Supplements, deputy editor of The Journal of the American Nutrition Association (www.nutrition.org), nutrition section editor of Annals of Medicine, and an advisory board member with Forbes Health.

A version of this article appeared on Medscape.com.

A growing body of research explores the link between stroke risk and regular consumption of coffee, tea, soda, and alcohol. This research roundup reviews the latest findings, highlighting both promising insights and remaining uncertainties to help guide discussions with your patients.

Coffee and Tea: Good or Bad? 

In the INTERSTROKE study, high coffee consumption (> 4 cups daily) was associated with an significantly increased risk for all strokes (odds ratio [OR], 1.37) or ischemic stroke (OR, 1.31), while low to moderate coffee had no link to increased stroke risk. In contrast, tea consumption was associated with lower odds of all stroke (OR, 0.81 for highest intake) or ischemic stroke (OR, 0.81). 

In a recent UK Biobank study, consumption of coffee or tea was associated with reduced risk for stroke and dementia, with the biggest benefit associated with consuming both beverages. 

Specifically, the investigators found that individuals who drank two to three cups of coffee and two to three cups of tea per day had a 30% decrease in incidence of stroke and a 28% lower risk for dementia versus those who did not.

A recent systematic review and dose-response meta-analysis showed that each daily cup increase in tea was associated with an average 4% reduced risk for stroke and a 2% reduced risk for cardiovascular disease (CVD) events. 

The protective effect of coffee and tea on stroke risk may be driven, in part, by flavonoids, which have antioxidant and anti-inflammatory properties, as well as positive effects on vascular function.

“The advice to patients should be that coffee and tea may protect against stroke, but that sweetening either beverage with sugar probably should be minimized,” said Cheryl Bushnell, MD, MHS, of Wake Forest University School of Medicine in Winston-Salem, North Carolina, and chair of the American Stroke Association (ASA) 2024 Guideline for the Primary Prevention of Stroke. 

Taylor Wallace, PhD, a certified food scientist, said, “most people should consume a cup or two of unsweetened tea per day in moderation for cardiometabolic health. It is an easy step in the right direction for good health but not a cure-all.”

When it comes to coffee, adults who like it should drink it “in moderation — just lay off the cream and sugar,” said Wallace, adjunct associate professor at George Washington University, Washington, DC, and Tufts University, Boston, Massachusetts.

“A cup or two of black coffee with low-fat or nonfat milk with breakfast is a healthy way to start the day, especially when you’re like me and have an 8-year-old that is full of energy!” Wallace said. 
 

The Skinny on Soda

When it comes to sugar-sweetened and diet beverages, data from the Nurses’ Health Study and Health Professionals Follow-Up Study, showed a 16% increased risk for stroke with one or more daily servings of sugar-sweetened or low-calorie soda per day (vs none), independent of established dietary and nondietary cardiovascular risk factors. 

In the Women’s Health Initiative Observational Study of postmenopausal women, a higher intake of artificially sweetened beverages was associated with increased risk for all stroke (adjusted hazard ratio [aHR], 1.23), ischemic stroke (aHR, 1.31), coronary heart disease (aHR, 1.29) and all-cause mortality (aHR, 1.16).

In the Framingham Heart Study Offspring cohort, consumption of one can of diet soda or more each day (vs none) was associated with a nearly threefold increased risk for stroke and dementia over a 10-year follow-up period. 

A separate French study showed that total artificial sweetener intake from all sources was associated with increased overall risk for cardiovascular and cerebrovascular disease.

However, given the limitations of these studies, it’s hard to draw any firm conclusions, Wallace cautioned. 

“We know that sugar-sweetened beverages are correlated with weight gain and cardiometabolic dysfunction promotion in children and adults,” he said. 

Yet, “there really isn’t any convincing evidence that diet soda has much impact on human health at all. Most observational studies are mixed and likely very confounded by other diet and lifestyle factors. That doesn’t mean go overboard; a daily diet soda is probably fine, but that doesn’t mean go drink 10 of them every day,” he added. 
 

Alcohol: Moderation or Abstinence?

Evidence on alcohol use and stroke risk have been mixed over the years. For decades, the evidence was suggestive that a moderate amount of alcohol daily (one to two drinks in men and one drink in women) may be beneficial at reducing major vascular outcomes.

Yet, over the past few years, some research has found no evidence of benefit with moderate alcohol intake. And the detrimental effects of excessive alcohol use are clear. 

A large meta-analysis showed that light to moderate alcohol consumption (up to one drink per day) was associated with a reduced risk for ischemic stroke. However, heavy drinking (more than two drinks per day) significantly increased the risk for both ischemic and hemorrhagic stroke.

A separate study showed young adults who are moderate to heavy drinkers are at increased risk for stroke — and the risk increases with more years of imbibing.

In the INTERSTROKE study, high to moderate alcohol consumption was associated with increased stroke risk, whereas low alcohol consumption conferred no increased risk. 

However, Bushnell pointed out that the study data was derived from based on self-report, and that other healthy behaviors may counteract the risk for alcohol consumption.

“For alcohol, regardless of stroke risk, the most important data shows that any alcohol consumption is associated with worse cognitive function, so generally, the lower the alcohol consumption the better,” Bushnell said. 

She noted that, currently, the American Heart Association (AHA)/ASA recommend a maximum of two drinks per day for men and one drink per day for women to reduce stroke risk.

“However, the data for the risk for cognitive impairment with any alcohol is convincing and should be kept in mind in addition to the maximum alcohol recommended by the AHA/ASA,” Bushnell advised. 

“We know excessive intake puts you at major risk for CVD, cancer, cognitive decline, and a whole host of other health ailments — no question there,” said Wallace.

The impact of moderate intake, on the other hand, is less clear. “Alcohol is a highly biased and political issue and the evidence (or lack thereof) on both sides is shoddy at best,” Wallace added.

A key challenge is that accurate self-reporting of alcohol intake is difficult, even for scientists, and most studies rely on self-reported data from observational cohorts. These often include limited dietary assessments, which provide only a partial picture of long-term consumption patterns, Wallace noted. 

“The short answer is we don’t know if moderation is beneficial, detrimental, or null with respect to health,” he said.

Bushnell reports no relevant disclosures. Wallace (www.drtaylorwallace.com) is CEO of Think Healthy Group; editor of The Journal of Dietary Supplements, deputy editor of The Journal of the American Nutrition Association (www.nutrition.org), nutrition section editor of Annals of Medicine, and an advisory board member with Forbes Health.

A version of this article appeared on Medscape.com.

TOPLINE:

Weekend exercise, involving one or two sessions per week, is associated with a similar reduction in risk for mild dementia as that reported with more frequent exercise, a new study shows. Investigators say the findings suggest even limited physical activity may offer protective cognitive benefits.

METHODOLOGY:

• Researchers analyzed the data of 10,033 participants in the Mexico City Prospective Study who were aged 35 years or older.
• Physical activity patterns were categorized into four groups: No exercise, weekend warriors (one or two sessions per week), regularly active (three or more sessions per week), and a combined group.
• Cognitive function was assessed using the Mini-Mental State Examination (MMSE).
• The analysis adjusted for confounders such as age, sex, education, income, blood pressure, smoking status, body mass index, civil status, sleep duration, diet, and alcohol intake.
• The mean follow-up duration was 16 years.

TAKEAWAY:

• When mild dementia was defined as an MMSE score ≤ 22, dementia prevalence was 26% in those who did not exercise, 14% in weekend warriors, and 18.5% in the regularly active group.
• When mild dementia was defined as an MMSE score ≤ 23, dementia prevalence was 30% in those who did not exercise, 20% in weekend warriors, and 22% in the regularly active group.
• Compared with people who did not exercise and after adjusting for confounding factors, risk for mild dementia was 13%-25% lower in weekend warriors, 11%-12% lower in the regular activity group, and 12%-16% lower in the two groups combined.
• The findings were consistent in men and women.

IN PRACTICE:

“To the best of our knowledge, this is the first prospective cohort study to show that the weekend warrior physical activity pattern and the regularly active physical activity pattern are associated with similar reductions in the risk of mild dementia. This study has important implications for policy and practice because the weekend warrior physical activity pattern may be a more convenient option for busy people around the world,” the authors wrote.

SOURCE:

The study was led by Gary O’Donovan, Faculty of Medicine, University of the Andes, Bogotá, Colombia. It was published online in the British Journal of Sports Medicine.

LIMITATIONS:

The survey respondents may not have been truly representative of middle-aged adults. Further, there were no objective measures of physical activity. The observational nature of the study does not provide insights into causality.

DISCLOSURES:

The study was funded by the Mexican Health Ministry, the National Council of Science and Technology for Mexico, Wellcome, and the UK Medical Research Council. No conflicts of interest were disclosed.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.
 

A version of this article appeared on Medscape.com.

TOPLINE:

Weekend exercise, involving one or two sessions per week, is associated with a similar reduction in risk for mild dementia as that reported with more frequent exercise, a new study shows. Investigators say the findings suggest even limited physical activity may offer protective cognitive benefits.

METHODOLOGY:

• Researchers analyzed the data of 10,033 participants in the Mexico City Prospective Study who were aged 35 years or older.
• Physical activity patterns were categorized into four groups: No exercise, weekend warriors (one or two sessions per week), regularly active (three or more sessions per week), and a combined group.
• Cognitive function was assessed using the Mini-Mental State Examination (MMSE).
• The analysis adjusted for confounders such as age, sex, education, income, blood pressure, smoking status, body mass index, civil status, sleep duration, diet, and alcohol intake.
• The mean follow-up duration was 16 years.

TAKEAWAY:

• When mild dementia was defined as an MMSE score ≤ 22, dementia prevalence was 26% in those who did not exercise, 14% in weekend warriors, and 18.5% in the regularly active group.
• When mild dementia was defined as an MMSE score ≤ 23, dementia prevalence was 30% in those who did not exercise, 20% in weekend warriors, and 22% in the regularly active group.
• Compared with people who did not exercise and after adjusting for confounding factors, risk for mild dementia was 13%-25% lower in weekend warriors, 11%-12% lower in the regular activity group, and 12%-16% lower in the two groups combined.
• The findings were consistent in men and women.

IN PRACTICE:

“To the best of our knowledge, this is the first prospective cohort study to show that the weekend warrior physical activity pattern and the regularly active physical activity pattern are associated with similar reductions in the risk of mild dementia. This study has important implications for policy and practice because the weekend warrior physical activity pattern may be a more convenient option for busy people around the world,” the authors wrote.

SOURCE:

The study was led by Gary O’Donovan, Faculty of Medicine, University of the Andes, Bogotá, Colombia. It was published online in the British Journal of Sports Medicine.

LIMITATIONS:

The survey respondents may not have been truly representative of middle-aged adults. Further, there were no objective measures of physical activity. The observational nature of the study does not provide insights into causality.

DISCLOSURES:

The study was funded by the Mexican Health Ministry, the National Council of Science and Technology for Mexico, Wellcome, and the UK Medical Research Council. No conflicts of interest were disclosed.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.
 

A version of this article appeared on Medscape.com.

TOPLINE:

Weekend exercise, involving one or two sessions per week, is associated with a similar reduction in risk for mild dementia as that reported with more frequent exercise, a new study shows. Investigators say the findings suggest even limited physical activity may offer protective cognitive benefits.

METHODOLOGY:

• Researchers analyzed the data of 10,033 participants in the Mexico City Prospective Study who were aged 35 years or older.
• Physical activity patterns were categorized into four groups: No exercise, weekend warriors (one or two sessions per week), regularly active (three or more sessions per week), and a combined group.
• Cognitive function was assessed using the Mini-Mental State Examination (MMSE).
• The analysis adjusted for confounders such as age, sex, education, income, blood pressure, smoking status, body mass index, civil status, sleep duration, diet, and alcohol intake.
• The mean follow-up duration was 16 years.

TAKEAWAY:

• When mild dementia was defined as an MMSE score ≤ 22, dementia prevalence was 26% in those who did not exercise, 14% in weekend warriors, and 18.5% in the regularly active group.
• When mild dementia was defined as an MMSE score ≤ 23, dementia prevalence was 30% in those who did not exercise, 20% in weekend warriors, and 22% in the regularly active group.
• Compared with people who did not exercise and after adjusting for confounding factors, risk for mild dementia was 13%-25% lower in weekend warriors, 11%-12% lower in the regular activity group, and 12%-16% lower in the two groups combined.
• The findings were consistent in men and women.

IN PRACTICE:

“To the best of our knowledge, this is the first prospective cohort study to show that the weekend warrior physical activity pattern and the regularly active physical activity pattern are associated with similar reductions in the risk of mild dementia. This study has important implications for policy and practice because the weekend warrior physical activity pattern may be a more convenient option for busy people around the world,” the authors wrote.

SOURCE:

The study was led by Gary O’Donovan, Faculty of Medicine, University of the Andes, Bogotá, Colombia. It was published online in the British Journal of Sports Medicine.

LIMITATIONS:

The survey respondents may not have been truly representative of middle-aged adults. Further, there were no objective measures of physical activity. The observational nature of the study does not provide insights into causality.

DISCLOSURES:

The study was funded by the Mexican Health Ministry, the National Council of Science and Technology for Mexico, Wellcome, and the UK Medical Research Council. No conflicts of interest were disclosed.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.
 

A version of this article appeared on Medscape.com.

Cannabis use may lead to thinning of the cerebral cortex in adolescents, research in mice and humans suggested.

The multilevel study demonstrated that tetrahydrocannabinol (THC), an active substance in cannabis, causes shrinkage of dendritic arborization — the neurons’ network of antennae that play a critical role in communication between brain cells.

The connection between dendritic arborization and cortical thickness was hinted at in an earlier study by Tomáš Paus, MD, PhD, professor of psychiatry and addictology at the University of Montreal, Quebec, Canada, and colleagues, who found that cannabis use in early adolescence was associated with lower cortical thickness in boys with a high genetic risk for schizophrenia.

“We speculated at that time that the differences in cortical thickness might be related to differences in dendritic arborization, and our current study confirmed it,” Paus said.

That confirmation came in the mouse part of the study, when coauthor Graciela Piñeyro, MD, PhD, also of the University of Montreal, counted the dendritic branches of mice exposed to THC and compared the total with the number of dendritic branches in unexposed mice. “What surprised me was finding that THC in the mice was targeting the same type of cells and structures that Dr. Paus had predicted would be affected from the human studies,” she said. “Structurally, they were mostly the neurons that contribute to synapses in the cortex, and their branching was reduced.”

Paus explained that in humans, a decrease in input from the affected dendrites “makes it harder for the brain to learn new things, interact with people, cope with new situations, et cetera. In other words, it makes the brain more vulnerable to everything that can happen in a young person’s life.”

The study was published online on October 9 in the Journal of Neuroscience.
 

Of Mice, Men, and Cannabis

Although associations between cannabis use by teenagers and variations in brain maturation have been well studied, the cellular and molecular underpinnings of these associations were unclear, according to the authors.

To investigate further, they conducted this three-step study. First, they exposed adolescent male mice to THC or a synthetic cannabinoid (WIN 55,212-2) and assessed differentially expressed genes, spine numbers, and the extent of dendritic complexity in the frontal cortex of each mouse.

Next, using MRI, they examined differences in cortical thickness in 34 brain regions in 140 male adolescents who experimented with cannabis before age 16 years and 327 who did not.

Then, they again conducted experiments in mice and found that 13 THC-related genes correlated with variations in cortical thickness. Virtual histology revealed that these 13 genes were coexpressed with cell markers of astrocytes, microglia, and a type of pyramidal cell enriched in genes that regulate dendritic expression.

Similarly, the WIN-related genes correlated with differences in cortical thickness and showed coexpression patterns with the same three cell types.

Furthermore, the affected genes were also found in humans, particularly in the thinner cortical regions of the adolescents who experimented with cannabis.

By acting on microglia, THC seems to promote the removal of synapses and, eventually, the reduction of the dendritic tree in mice, Piñeyro explained. That’s important not only because a similar mechanism may be at work in humans but also because “we now might have a model to test different types of cannabis products to see which ones are producing the greatest effect on neurons and therefore greater removal of synapses through the microglia. This could be a way of testing drugs that are out in the street to see which would be the most or least dangerous to the synapses in the brain.”
 

‘Significant Implications’

Commenting on the study, Yasmin Hurd, PhD, Ward-Coleman chair of translational neuroscience at the Icahn School of Medicine at Mount Sinai and director of the Addiction Institute of Mount Sinai in New York City, said, “These findings are in line with previous results, so they are feasible. This study adds more depth by showing that cortical genes that were differentially altered by adolescent THC correlated with cannabis-related changes in cortical thickness based on human neuroimaging data.” Hurd did not participate in the research.

“The results emphasize that consumption of potent cannabis products during adolescence can impact cortical function, which has significant implications for decision-making and risky behavior as well. It also can increase vulnerability to psychiatric disorders such as schizophrenia.”

Although a mouse model is “not truly the same as the human condition, the fact that the animal model also showed evidence of the morphological changes indicative of reduced cortical thickness, [like] the humans, is strong,” she said.

Additional research could include women and assess potential sex differences, she added.

Ronald Ellis, MD, PhD, an investigator in the Center for Medicinal Cannabis Research at the University of California, San Diego School of Medicine, said, “The findings are plausible and extend prior work showing evidence of increased risk for psychotic disorders later in life in adolescents who use cannabis.” Ellis did not participate in the research.

“Future studies should explore how these findings might vary across different demographic groups, which could provide a more inclusive understanding of how cannabis impacts the brain,” he said. “Additionally, longitudinal studies to track changes in the brain over time could help to establish causal relationships more robustly.

“The take-home message to clinicians at this point is to discuss cannabis use history carefully and confidentially with adolescent patients to better provide advice on its potential risks,” he concluded.

Paus added that he would tell patients, “If you’re going to use cannabis, don’t start early. If you have to, then do so in moderation. And if you have family history of mental illness, be very careful.”

No funding for the study was reported. Paus, Piñeyro, Hurd, and Ellis declared having no relevant financial relationships. 
 

A version of this article appeared on Medscape.com.

Cannabis use may lead to thinning of the cerebral cortex in adolescents, research in mice and humans suggested.

The multilevel study demonstrated that tetrahydrocannabinol (THC), an active substance in cannabis, causes shrinkage of dendritic arborization — the neurons’ network of antennae that play a critical role in communication between brain cells.

The connection between dendritic arborization and cortical thickness was hinted at in an earlier study by Tomáš Paus, MD, PhD, professor of psychiatry and addictology at the University of Montreal, Quebec, Canada, and colleagues, who found that cannabis use in early adolescence was associated with lower cortical thickness in boys with a high genetic risk for schizophrenia.

“We speculated at that time that the differences in cortical thickness might be related to differences in dendritic arborization, and our current study confirmed it,” Paus said.

That confirmation came in the mouse part of the study, when coauthor Graciela Piñeyro, MD, PhD, also of the University of Montreal, counted the dendritic branches of mice exposed to THC and compared the total with the number of dendritic branches in unexposed mice. “What surprised me was finding that THC in the mice was targeting the same type of cells and structures that Dr. Paus had predicted would be affected from the human studies,” she said. “Structurally, they were mostly the neurons that contribute to synapses in the cortex, and their branching was reduced.”

Paus explained that in humans, a decrease in input from the affected dendrites “makes it harder for the brain to learn new things, interact with people, cope with new situations, et cetera. In other words, it makes the brain more vulnerable to everything that can happen in a young person’s life.”

The study was published online on October 9 in the Journal of Neuroscience.
 

Of Mice, Men, and Cannabis

Although associations between cannabis use by teenagers and variations in brain maturation have been well studied, the cellular and molecular underpinnings of these associations were unclear, according to the authors.

To investigate further, they conducted this three-step study. First, they exposed adolescent male mice to THC or a synthetic cannabinoid (WIN 55,212-2) and assessed differentially expressed genes, spine numbers, and the extent of dendritic complexity in the frontal cortex of each mouse.

Next, using MRI, they examined differences in cortical thickness in 34 brain regions in 140 male adolescents who experimented with cannabis before age 16 years and 327 who did not.

Then, they again conducted experiments in mice and found that 13 THC-related genes correlated with variations in cortical thickness. Virtual histology revealed that these 13 genes were coexpressed with cell markers of astrocytes, microglia, and a type of pyramidal cell enriched in genes that regulate dendritic expression.

Similarly, the WIN-related genes correlated with differences in cortical thickness and showed coexpression patterns with the same three cell types.

Furthermore, the affected genes were also found in humans, particularly in the thinner cortical regions of the adolescents who experimented with cannabis.

By acting on microglia, THC seems to promote the removal of synapses and, eventually, the reduction of the dendritic tree in mice, Piñeyro explained. That’s important not only because a similar mechanism may be at work in humans but also because “we now might have a model to test different types of cannabis products to see which ones are producing the greatest effect on neurons and therefore greater removal of synapses through the microglia. This could be a way of testing drugs that are out in the street to see which would be the most or least dangerous to the synapses in the brain.”
 

‘Significant Implications’

Commenting on the study, Yasmin Hurd, PhD, Ward-Coleman chair of translational neuroscience at the Icahn School of Medicine at Mount Sinai and director of the Addiction Institute of Mount Sinai in New York City, said, “These findings are in line with previous results, so they are feasible. This study adds more depth by showing that cortical genes that were differentially altered by adolescent THC correlated with cannabis-related changes in cortical thickness based on human neuroimaging data.” Hurd did not participate in the research.

“The results emphasize that consumption of potent cannabis products during adolescence can impact cortical function, which has significant implications for decision-making and risky behavior as well. It also can increase vulnerability to psychiatric disorders such as schizophrenia.”

Although a mouse model is “not truly the same as the human condition, the fact that the animal model also showed evidence of the morphological changes indicative of reduced cortical thickness, [like] the humans, is strong,” she said.

Additional research could include women and assess potential sex differences, she added.

Ronald Ellis, MD, PhD, an investigator in the Center for Medicinal Cannabis Research at the University of California, San Diego School of Medicine, said, “The findings are plausible and extend prior work showing evidence of increased risk for psychotic disorders later in life in adolescents who use cannabis.” Ellis did not participate in the research.

“Future studies should explore how these findings might vary across different demographic groups, which could provide a more inclusive understanding of how cannabis impacts the brain,” he said. “Additionally, longitudinal studies to track changes in the brain over time could help to establish causal relationships more robustly.

“The take-home message to clinicians at this point is to discuss cannabis use history carefully and confidentially with adolescent patients to better provide advice on its potential risks,” he concluded.

Paus added that he would tell patients, “If you’re going to use cannabis, don’t start early. If you have to, then do so in moderation. And if you have family history of mental illness, be very careful.”

No funding for the study was reported. Paus, Piñeyro, Hurd, and Ellis declared having no relevant financial relationships. 
 

A version of this article appeared on Medscape.com.

Cannabis use may lead to thinning of the cerebral cortex in adolescents, research in mice and humans suggested.

The multilevel study demonstrated that tetrahydrocannabinol (THC), an active substance in cannabis, causes shrinkage of dendritic arborization — the neurons’ network of antennae that play a critical role in communication between brain cells.

The connection between dendritic arborization and cortical thickness was hinted at in an earlier study by Tomáš Paus, MD, PhD, professor of psychiatry and addictology at the University of Montreal, Quebec, Canada, and colleagues, who found that cannabis use in early adolescence was associated with lower cortical thickness in boys with a high genetic risk for schizophrenia.

“We speculated at that time that the differences in cortical thickness might be related to differences in dendritic arborization, and our current study confirmed it,” Paus said.

That confirmation came in the mouse part of the study, when coauthor Graciela Piñeyro, MD, PhD, also of the University of Montreal, counted the dendritic branches of mice exposed to THC and compared the total with the number of dendritic branches in unexposed mice. “What surprised me was finding that THC in the mice was targeting the same type of cells and structures that Dr. Paus had predicted would be affected from the human studies,” she said. “Structurally, they were mostly the neurons that contribute to synapses in the cortex, and their branching was reduced.”

Paus explained that in humans, a decrease in input from the affected dendrites “makes it harder for the brain to learn new things, interact with people, cope with new situations, et cetera. In other words, it makes the brain more vulnerable to everything that can happen in a young person’s life.”

The study was published online on October 9 in the Journal of Neuroscience.
 

Of Mice, Men, and Cannabis

Although associations between cannabis use by teenagers and variations in brain maturation have been well studied, the cellular and molecular underpinnings of these associations were unclear, according to the authors.

To investigate further, they conducted this three-step study. First, they exposed adolescent male mice to THC or a synthetic cannabinoid (WIN 55,212-2) and assessed differentially expressed genes, spine numbers, and the extent of dendritic complexity in the frontal cortex of each mouse.

Next, using MRI, they examined differences in cortical thickness in 34 brain regions in 140 male adolescents who experimented with cannabis before age 16 years and 327 who did not.

Then, they again conducted experiments in mice and found that 13 THC-related genes correlated with variations in cortical thickness. Virtual histology revealed that these 13 genes were coexpressed with cell markers of astrocytes, microglia, and a type of pyramidal cell enriched in genes that regulate dendritic expression.

Similarly, the WIN-related genes correlated with differences in cortical thickness and showed coexpression patterns with the same three cell types.

Furthermore, the affected genes were also found in humans, particularly in the thinner cortical regions of the adolescents who experimented with cannabis.

By acting on microglia, THC seems to promote the removal of synapses and, eventually, the reduction of the dendritic tree in mice, Piñeyro explained. That’s important not only because a similar mechanism may be at work in humans but also because “we now might have a model to test different types of cannabis products to see which ones are producing the greatest effect on neurons and therefore greater removal of synapses through the microglia. This could be a way of testing drugs that are out in the street to see which would be the most or least dangerous to the synapses in the brain.”
 

‘Significant Implications’

Commenting on the study, Yasmin Hurd, PhD, Ward-Coleman chair of translational neuroscience at the Icahn School of Medicine at Mount Sinai and director of the Addiction Institute of Mount Sinai in New York City, said, “These findings are in line with previous results, so they are feasible. This study adds more depth by showing that cortical genes that were differentially altered by adolescent THC correlated with cannabis-related changes in cortical thickness based on human neuroimaging data.” Hurd did not participate in the research.

“The results emphasize that consumption of potent cannabis products during adolescence can impact cortical function, which has significant implications for decision-making and risky behavior as well. It also can increase vulnerability to psychiatric disorders such as schizophrenia.”

Although a mouse model is “not truly the same as the human condition, the fact that the animal model also showed evidence of the morphological changes indicative of reduced cortical thickness, [like] the humans, is strong,” she said.

Additional research could include women and assess potential sex differences, she added.

Ronald Ellis, MD, PhD, an investigator in the Center for Medicinal Cannabis Research at the University of California, San Diego School of Medicine, said, “The findings are plausible and extend prior work showing evidence of increased risk for psychotic disorders later in life in adolescents who use cannabis.” Ellis did not participate in the research.

“Future studies should explore how these findings might vary across different demographic groups, which could provide a more inclusive understanding of how cannabis impacts the brain,” he said. “Additionally, longitudinal studies to track changes in the brain over time could help to establish causal relationships more robustly.

“The take-home message to clinicians at this point is to discuss cannabis use history carefully and confidentially with adolescent patients to better provide advice on its potential risks,” he concluded.

Paus added that he would tell patients, “If you’re going to use cannabis, don’t start early. If you have to, then do so in moderation. And if you have family history of mental illness, be very careful.”

No funding for the study was reported. Paus, Piñeyro, Hurd, and Ellis declared having no relevant financial relationships. 
 

A version of this article appeared on Medscape.com.