After years of vilifying it, we’ve finally welcomed dietary fat back into our lives with open arms. Why? We now know that good fats can lower bad cholesterol, tamp down inflammation, and reduce risk of death by 27 percent, according to Harvard research.
But, a new Ohio State University study suggests all the great benefits that come from eating good fat can be overridden by stress.
In the study, published in the journal Molecular Psychiatry, researchers recruited 58 women, 38 of which were breast cancer survivors. The women visited Ohio State two days a week and ate a high-calorie, high-fat breakfast consisting of biscuits and gravy, eggs, and turkey sausage. There were randomly assigned to eat one higher in less-healthy saturated fat derived from palm oil and one higher in healthier unsaturated fat from a sunflower oil high in oleic acid. The researchers chose to mimic a typical fast-food meal; the biscuits-and-gravy breakfast was almost identical in macros to that of a Big Mac and medium fries or a Burger King Double Whopper with cheese—yielding 930 calories and 60 grams of fat. The women were given 20 minutes to eat.
Participants’ blood was drawn multiple times during their visits to analyze two markers of inflammation: C-reactive protein and serum amyloid A. Researchers also evaluated markers, called cell adhesion molecules, thought to predict a greater likelihood of plaque buildup in arteries.
The women were asked about the previous day’s experiences to determine if they were stressed. The researchers say minor irritants didn’t count as a stressful day; stressors included things like having to clean up paint a child spilled all over the floor and struggling to help a parent with dementia who was resisting help. “They’re not life-shattering events, but they’re not of the hangnail variety either,” lead study author Jan Kiecolt-Glaser said in a press release.
At the study’s conclusion, un-stressed women who ate a biscuits-and-gravy breakfast made with saturated fat fared worse in blood tests looking for precursors of disease than women who ate an identical breakfast made primarily with monounsaturated sunflower oil. But, when women had a stressful event before the breakfast test, the hardships of the previous day appeared to erase any benefits linked to the healthy fat choice, the researchers say (31 women reported at least one recent stressor at either of the two visits, 21 had experienced stress before both visits, and six reported no significant stressful experiences prior to their visits).
All four unhealthy markers were higher following the unhealthy saturated fat meal compared to the unsaturated fat meal, even after controlling for blood levels before eating, age difference, abdominal fat, and physical activity—all factors that can skew results. And stress raised levels of all four harmful blood markers in the healthier unsaturated fat meal group.
Researchers knew both diet and stress could alter inflammation in the body and trigger conditions like heart disease, diabetes, and rheumatoid arthritis. But this is the first time the interplay between stress, diet, and inflammatory markers has been measured. Stress makes a marked impact not just on your mental health, but on your all-around well-being, so much so that eating a breakfast with “bad fat” wasn’t any better than eating one with “good fat.”
Up next, researchers might explore the relationship among stress, fat source, and healthier meals higher in fiber and fruits and vegetables, and lower in calories.
To reduce inflammation in your body and ward off chronic disease, the researchers suggest eating healthier foods that are associated with the Mediterranean diet—foods high in oleic acid (think: olive oil), says co-author Martha Belury.
Kiecolt-Glaser and Belury also stress that while inflammation creeps up over time to contribute to disease, don’t think it’s a free pass to eat whatever you want when you’re stressed. It’s tempting; but Belury says reaching for healthier choices every day can you put you in a better position, health-wise, when stress strikes.