An elemental diet was more than 90% effective in inducing histologic remission in eosinophilic esophagitis patients, reported Dr. Ángel Arias and colleagues in the June issue of Gastroenterology.
The Six Food Elimination Diet was also highly efficacious, reinforcing the idea that dietary modification "should be considered as a first-line therapy in both children and adults affected by this disease," wrote the investigators (doi:10.1053/j.gastro.2014.02.006).
Dr. Arias of the Complejo Hospitalario La Mancha Centro, in Alcázar de San Juan, Spain, searched the MEDLINE, EMBASE, and SCOPUS databases for studies performed prior to June 2013 investigating the efficacy of dietary interventions in eosinophilic esophagitis (EoE).
Abstracts and other relevant material from conferences including Digestive Disease Week, the American College of Gastroenterology meeting, and European Gastroenterology Week were also included.
Overall, 33 studies were included, 23 of which were full articles with the remainder being abstracts; there were a total of 1,128 children and 189 adults included in the analysis.
Of the 13 studies that assessed the efficacy of exclusive feeding with an amino acid–based elemental diet (involving 411 children and 18 adults), 90.8% of patients achieved histologic remission of EoE, defined as fewer than 15 eosinophils per high-power field on esophageal biopsy (95% confidence interval, 84.7%-95.5%).
The next best diet, the Six Food Elimination Diet (SFED), offered a 72.1% efficacy rate (95% CI, 65.8%-78.1%) across 75 children and 122 adults and was "the only one assessed in more adults than children."
On the other hand, the strategy of eliminating foods that gave a positive result in skin allergy tests was assessed in 14 studies (594 children and 32 adults), and demonstrated an overall efficacy of just 45.5% (95% CI, 35.4%-55.7%).
Other less-studied diets included gluten-free and cow’s milk elimination diets, both of which seemed to result in histologic remission (58.7% and 68.2%, respectively).
However, "because studies assessing these dietary treatments are still scarce, making conclusions from them can be risky," wrote the authors.
"For example, although the overall efficacy of a gluten-free diet in achieving histologic remission of EoE was 58.7%, the remission rate ranged from 23.1% to 85.6%," they reported.
"Despite its obvious success, the multiple drawbacks of elemental diets, which include the need to avoid all table food, its unpleasant taste, and high cost, and the psychological effects produced by the social limitations that this diet entails, have probably contributed to the fact that this dietary intervention has been restricted almost exclusively to pediatric patients," commented Dr. Arias.
"In fact, no research on adults was available until 2013, with the reported remission rates being comparable with those documented in children."
On the other hand, the relatively high efficacy of the SFED diet, which avoids many of the disadvantages of the elemental diet, seems to make this the best choice for "children and motivated adult patients," added the researchers.
Future studies and meta-analyses should address whether diet adherence results in changes in esophageal fibrosis as well as quality of life issues brought on by diet adherence.
The authors disclosed no relevant financial conflicts.