Livin' on the MDedge

Stressed about weight gain? Well, stress causes weight gain


Stress, meet weight gain. Weight gain, meet stress

You’re not eating differently and you’re keeping active, but your waistline is expanding. How is that happening? Since eating healthy and exercising shouldn’t make you gain weight, there may be a hidden factor getting in your way. Stress. The one thing that can have a grip on your circadian rhythm stronger than any bodybuilder.

Vectorial illustration of a clock with human hands, representing the circadian rhythm of sleep and wakefulness. In the balanced cycle, a half circle contains the night and the other one the day. Francesca Bellini/iStock/Getty Images

Investigators at Weill Cornell Medicine published two mouse studies that suggest stress and other factors that throw the body’s circadian clocks out of rhythm may contribute to weight gain.

In the first study, the researchers imitated disruptive condition effects like high cortisol exposure and chronic stress by implanting pellets under the skin that released glucocorticoid at a constant rate for 21 days. Mice that received the pellets had twice as much white and brown fat, as well as much higher insulin levels, regardless of their unchanged and still-healthy diet.

In the second study, they used tagged proteins as markers to monitor the daily fluctuations of a protein that regulates fat cell production and circadian gene expression in mouse fat cell precursors. The results showed “that fat cell precursors commit to becoming fat cells only during the circadian cycle phase corresponding to evening in humans,” they said in a written statement.

“Every cell in our body has an intrinsic cell clock, just like the fat cells, and we have a master clock in our brain, which controls hormone secretion,” said senior author Mary Teruel of Cornell University. “A lot of forces are working against a healthy metabolism when we are out of circadian rhythm. The more we understand, the more likely we will be able to do something about it.”

So if you’re stressing out that the scale is or isn’t moving in the direction you want, you could be standing in your own way. Take a chill pill.

Who can smell cancer? The locust nose

If you need to smell some gas, there’s nothing better than a nose. Just ask a scientist: “Noses are still state of the art,” said Debajit Saha, PhD, of Michigan State University. “There’s really nothing like them when it comes to gas sensing.”

locust in researcher's hand Derrick L. Turner

And when it comes to noses, dogs are best, right? After all, there’s a reason we don’t have bomb-sniffing wombats and drug-sniffing ostriches. Dogs are better. Better, but not perfect. And if they’re not perfect, then human technology can do better.

Enter the electronic nose. Which is better than dogs … except that it isn’t. “People have been working on ‘electronic noses’ for more than 15 years, but they’re still not close to achieving what biology can do seamlessly,” Dr. Saha explained in a statement from the university.

Which brings us back to dogs. If you want to detect early-stage cancer using smell, you go to the dogs, right? Nope.

Here’s Christopher Contag, PhD, also of Michigan State, who recruited Dr. Saha to the university: “I told him, ‘When you come here, we’ll detect cancer. I’m sure your locusts can do it.’ ”

Yes, locusts. Dr. Contag and his research team were looking at mouth cancers and noticed that different cell lines had different appearances. Then they discovered that those different-looking cell lines produced different metabolites, some of which were volatile.

Enter Dr. Saha’s locusts. They were able to tell the difference between normal cells and cancer cells and could even distinguish between the different cell lines. And how they were able to share this information? Not voluntarily, that’s for sure. The researchers attached electrodes to the insects’ brains and recorded their responses to gas samples from both healthy and cancer cells. Those brain signals were then used to create chemical profiles of the different cells. Piece of cake.

The whole getting-electrodes-attached-to-their-brains thing seemed at least a bit ethically ambiguous, so we contacted the locusts’ PR office, which offered some positive spin: “Humans get their early cancer detection and we get that whole swarms-that-devour-entire-countrysides thing off our backs. Win win.”


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