A fair number of the patients I see are already eating a healthy diet but they’re still not feeling well. Once we delve deep into their history and their lives, it becomes very clear that stress is at the bedrock of their illness. It’s extremely frustrating to be eating well all the time but still experiencing symptoms.
We know that stress shuts down digestion including suppression of stomach acid, bile flow, and pancreatic function. All of these are necessary for healthy digestion but if we’re stressed while we are eating, that healthy food we’re putting into our bodies won’t get digested properly and it may have some more interesting effects on the body.
Stress also immediately changes the behavior of your gut bacteria which also influences how your food is digested and absorbed.
I decided to look deeper into this connection and I found a very interesting paper entitled, “Depression, Daily Stressors, and Inflammatory Responses to High-Fat Meals: When Stress Overrides Healthier Food Choices.” The paper was published in the journal Molecular Psychiatry in March of 2017.
Let’s dig in and break down what the researchers found. 58 healthy women with a mean age of 53 received either a high saturated fat meal or a high oleic sunflower oil meal. An inventory of stressful events was assessed prior to consuming the meal.
The researchers found as expected that women without any prior day stressors showed increased signs of inflammation after the high saturated fat meal but no increase in inflammation after the sunflower oil meal.
This is expected because too much saturated fat increases inflammation and monounsaturated oils that are high in oleic acid such as sunflower oil or olive oil do not increase inflammation when eaten in excess. In fact, olive oil has been shown in studies not to increase inflammation when eaten in excess and also it has been shown to decrease inflammation.
However, any of the women who had prior day stressors showed an increase in inflammation after eating the high saturated fat meal as well as the high sunflower oil meal. The results looked identical after eating both types of fat. This clearly showed that if you have been under stress, eating fats that don’t increase inflammation such as sunflower or olive oil will still increase inflammation.
They also found that the more daily stressors the subjects had leading up to the meals, the greater the levels of inflammation after the sunflower oil meal but not the saturated fat meal. So saturated fat had a cut-off effect when more stressors were accumulated.
Additionally, any of the women who had a history of major depressive disorder showed an abnormal increase in blood pressure after the high-fat meal of both types. The authors go on to discuss how this increase in inflammation promotes plaquing of the arteries and can lead to diabetes by increasing insulin resistance.
The authors also discuss the connection between a history of depression and how people respond to stressors. Those with any history of depression or PTSD show an amplified response to stressors compared to those without such history.
Previous studies have also shown that marital stress can lead to higher insulin and triglyceride levels post-meal.
What did they eat?
The subjects at eggs, turkey sausage, biscuits, and gravy which contained 60 grams of fat, 59 grams of carbohydrates, and 36 grams of protein. The authors point out that these types of numbers are similar to that of a Burger King Double Whopper with cheese or a Big Mac cheeseburger and medium French fries.
How was inflammation measured?
Blood testing included CRP(c-reactive protein), serum amyloid A, sICAM-1, and sVCAM-1. SICAM-1 and sVCAM-1 are specific indicators of increased damage to arteries thus potentially leading to atherosclerosis.
Dr. Hedberg’s Comments
It is interesting that more daily stressors did not increased inflammation above a certain point in those who ate the high saturated fat meal but inflammation did increase in those who ate the high sunflower oil meal. Saturated fat appears to have a limiting effect on inflammation to a certain point.
The first weakness of this study and the authors point this out, is that these meals contained refined flour without much fiber. Perhaps a healthier meal with added vegetables, more protein, and whole grains or fruit combined with the high fat would yield different results.
Additionally, 38 out of the 58 subjects were healthy breast cancer survivors. Cancer is an extremely traumatic diagnosis which can lead to significant stress while going through treatment. A healthier population may have been a better choice for study participants.
Despite the weaknesses, this study does do an excellent job of showing the negative effects of stress on what we eat. What I would take away from this is that we need to put all of our efforts into reducing stress, even more so than with food. Diet can become stressful and confusing by itself but when we add daily stressors to the mix our bodies won’t respond the way we would like.
One could also take away from this that we shouldn’t feel too guilty if we binge on junk food when we’re really stressed, because inflammation will still increase even if we are eating healthier foods. If you’re going to cheat, and we all do sometimes, you might as well eat what you want and not try to do “healthy cheating.”
I hope this is a reminder to focus on stress reduction techniques as much as possible so all your efforts to eat healthily don’t go to waste.