Can Stress Ruin A Healthy Diet?

I understand that stress can undermine the benefits of a healthy diet. This is discouraging news since stress is so hard to escape. How bad and long-lasting does stress have to be to have this effect?

– December 16, 2016

A study from Ohio State University looked at how stress can affect the health benefits of eating a meal made with monounsaturated fat compared to one made with saturated fat. The researchers, led by Janice Kiecolt-Glaser, director of the Ohio State Institute for Behavioral Medicine, noted that the study is the first to show that stress can cancel out the benefits associated with consuming healthy fat. Specifically, the investigation measured the effect of stress on inflammation in the body in response to eating meals of healthy or unhealthy fats.

We know that over time chronic, imperceptible low-level inflammation gives rise to many serious, age-related diseases, including heart disease, cancer and neurodegenerative conditions such as Alzheimer’s and Parkinson’s diseases, as well as to depression.

Chronic inflammation is associated with genetic factors, a sedentary lifestyle, too much stress, exposure to environmental toxins such as secondhand tobacco smoke, and with diet. I believe that most people in our part of the world go through life in a pro-inflammatory state primarily as a result of what they eat, but the other contributors shouldn’t be taken lightly, especially those that can be controlled.

For their study, the Ohio State researchers randomly assigned 58 women to eat one of two breakfasts that included biscuits and gravy, eggs, and turkey sausage. One meal was high in unhealthy saturated fat from palm oil while the other was made with monounsaturated sunflower oil. The breakfast was designed to mimic a typical fast-food meal, such as a Big Mac plus a medium order of fries or a Burger King Double Whopper with cheese. It provided 930 calories and 60 grams of fat.

After breakfast, the women had blood tests to measure 2 markers of inflammation: C-reactive protein and serum amyloid A, as well as cell adhesion molecules, which can predict the formation of plaque in arteries.

The researchers reported that unstressed women who ate the breakfast high in saturated fat had worse test results than unstressed women who ate a similar breakfast made primarily with monounsaturated fat. However, when any of the women reported having been under stress the previous day or before breakfast, the benefits of consuming the healthy fat disappeared.

The women’s stress levels were assessed with a standardized questionnaire when they arrived for breakfast. The researchers also asked about any stress they had experienced the previous day. Minor irritants were ignored. Stressors that did matter included such things as having to clean up paint that a child had spilled all over the floor or struggling to help a parent with dementia. “They’re not life-shattering events, but they’re not of the hangnail variety eithers,” Dr. Kiecolt-Glaser explained in a press release that accompanied publication of the study results.

Rather than focusing on the detriments of stress, the researchers noted that their findings could serve as a reminder that aiming for healthy food choices on a daily basis would give you an advantage when stress does strike and promotes inflammation.

I agree. I’m convinced that the single most important step you can take to counter chronic inflammation is to stop eating refined, processed and manufactured foods.

Andrew Weil, M.D.


Janice Kiecolt-Glaser et al, “Depression, daily stressors and inflammatory responses to high-fat meals: when stress overrides healthier food choices,” Molecular Psychiatry, September 20, 2016, doi:10.1038/mp.2016.149

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