Chronic Stress Increases Risk of Diet-Related Metabolic Issues

Statistics show that almost 35 percent of Americans are affected by a metabolic syndrome, a combination of factors including heart disease, stroke and/or diabetes, which is often times exacerbated by stress.

A recent study conducted by researchers from UC San Francisco examined how highly stressed individuals who regularly consume high-fat, high-sugar foods are more prone to health risks than those with less stress who follow the same unhealthy diet.  

"Chronic stress can play an important role in influencing biology, and it's critical to understand the exact pathways through which it works," said Kirstin Aschbacher, PhD, an assistant professor in the UCSF Department of Psychiatry and lead author, via a press release. "Many people think a calorie is a calorie, but this study suggests that two women who eat the same thing could have different metabolic responses based on their level of stress. There appears to be a stress pathway that works through diet - for example, it could be similar to what we see in animals, where fat cells grow faster in response to junk food when the body is chronically stressed."

Researchers note that this is the first study to suggest that chronic stress combined with an unhealthy diet in humans can lead to metabolic disorders.

For the study, researchers examined a group of 61 disease-free women. Thirty-three were chronically stressed and caring for a spouse or parent with dementia while 28 had low stress. Dietary habits were recorded throughout the year.

"We can see this relationship exists by simply measuring stress and dietary intake, and looking inside at metabolic health," said senior author Elissa Epel, via the release. "Diet appears to be a critical variable that can either amplify or protect against the metabolic effects of stress, but we still don't know the details of how much it takes. It will be helpful to see what happens in our next study, when we have high stress people eat a high sugar diet for a couple weeks."

Next, researchers measured participants' waistlines and their fat distribution, including ultrasound scans to better assess how deep abdominal fat deposits were located. Insulin resistance and oxidative damage was also measured to better predict higher rates of death from diabetes.

"We found that more frequent high fat, high sugar consumption significantly predicted a larger waistline, more truncal fat, higher oxidative damage, and more insulin resistance, but only among the group of women exposed to chronic stress," said Aschbacher, via the release. "The chronically stressed women didn't report eating more high sugar, high fat foods than the low stressed women; however, they did have higher levels of a stress-related biomarker, peripheral Neuropeptide Y (NPY)."

Study findings showed that stress increases the risk of peripheral NPY. With a diet high in junk food, this can create larger abdominal fat cells and an increased risk of metabolic dysregulation.

"The medical community is starting to appreciate how important chronic stress is in promoting and worsening early disease processes," said Aschbacher. "But there are no guidelines for 'treating' chronic stress. We need treatment studies to understand whether increasing stress resilience could reduce the metabolic syndrome, obesity or diabetes."

More information regarding the findings can be seen via the journal Psychoneuroendocrinology.