Just as stress can affect nutrition, nutrition can affect stress

Are you feeling stressed?  If you’re like most people, chances are the answer is yes.  As if the daily pressures of life weren’t enough, the COVID-19 pandemic has pushed stress levels to new heights.  A recent study, for example, found that 38% of study participants had experienced some degree of distress due to COVID-19.  Moreover, an additional 16% were highly distressed “and likely in need of mental health services.”

These relationships are clinically meaningful, yet there has been so little clinical research in this area.

As nutrition scientists, practitioners and policymakers, we are particularly interested in learning how stress affects nutrition and, conversely, how nutrition affects stress.  Dr. Elissa Epel, Professor and Vice Chair of the Department of Psychiatry & Behavioral Sciences at the University of California, San Francisco, has dedicated much of her career to addressing these questions.  According to Dr. Epel, “these relationships are clinically meaningful, yet there has been so little clinical research in this area.”  Recently, Dr. Epel shared her insights into the complex relationships between stress, nutrition, and chronic disease during Food and the Aging Brain: Updates on Nutrition and Cognitive Health in Older Adults, a webinar sponsored by the Food Forum, with support from Sarah Ohlhorst, ASN’s Chief Science Policy Officer, who served on the planning committee.  

During the webinar, Dr. Epel explained how stress triggers our drive for comfort food, including excess sugar-sweetened beverages and sweets such as baked goods.  At the same time, during times of stress, we tend to lower our intake of whole foods, fruits, and vegetables.  This, in turn, leads to a higher risk of insulin resistance, excess visceral fat, and type 2 diabetes.

Stress has its own deleterious effects on health, but eating junk food while stressed synergistically leads to metabolic havoc.

Interestingly, stress appears to have its own impact on health outcomes independent of its impact on the food we select.  Dr. Epel pointed to an animal model study in which rodents were fed a “junk food” diet.  A subset of the rodents were exposed to chronic stress (such as predator odors).  The junk food alone did not lead to an increase in visceral fat among the rodents, but when the animals were also stressed, the combination of stress and poor diet substantially increased visceral fat and the risk of early metabolic disease.

Dr. Epel and colleagues have found that these same relationships exist among people.  In one study, for example, highly stressed maternal caregivers exhibited greater compulsive eating and increased abdominal fat over several years.

Just as stress can affect nutrition, nutrition can affect stress.  As evidence, Dr. Epel discussed the results of population-based studies that found that dietary patterns emphasizing whole foods were associated with lower depression, anxiety and stress, whereas a typical Western dietary pattern was associated with a higher risk of poor mental health.  In addition, Dr. Epel’s research has found that mindful eating during pregnancy, particularly among low-income women with overweight, can reduce stress eating and improve glucose control.

Studies published in ASN journals echo Dr. Epel’s findings demonstrating how stress and our overall emotional state shape our eating behavior and food choices.  For example, in his Advances in Nutrition review, “The Effects of Psychological and Environmental Stress on Micronutrient Concentrations in the Body: A Review of the Evidence,” Adrian L. Lopresti noted that “although research is somewhat limited and the robustness of research is variable, the bulk of evidence suggests psychological and physical stress can influence concentrations of several micronutrients.”  In particular, the author pointed to studies that found a link between stress and the depletion of magnesium, zinc, calcium, and iron concentrations.

Chronic stress played a role in negatively influencing dietary behaviors.

A study published in Current Developments in Nutrition, “Chronic Stress and Unhealthy Dietary Behaviors among Low-Income African-American Female Caregivers,” found that “chronic stress played a role in negatively influencing dietary behaviors.”  In particular, a connection was seen between chronic stress and a higher consumption of soda and fatty foods.  The authors, Sungwoo Lim et al., noted that “almost 41% of this association was explained by an indirect pathway through depressive symptoms.”

A similar study published in The American Journal of Clinical Nutrition, “Occupational Burnout, Eating Behavior, and Weight among Working Women,” found that women experiencing occupational burnout, resulting from chronic on-the-job stress, “may be more vulnerable to emotional eating and uncontrolled eating and have a hindered ability to make changes in their eating behavior.”  Among subjects who were overweight or obese, authors Nina J. Nevanperä et al. noted, “failure to make changes due to burnout and reduced resources may impair self-esteem and self-efficacy, which are important for achieving success in weight maintenance.”

Another facet of stress eating is emotional eating, which refers to how we eat in response to negative emotions often brought on by stress.  The topic was addressed in “The Associations between Emotional Eating and Consumption of Energy-Dense Snack Foods Are Modified by Sex and Depressive Symptomatology,” published in The Journal of Nutrition.  Authors Géraldine M. Camilleri et al. observed “a positive association between emotional eating and energy-dense snack-food intake.”  Interestingly, among women the presence of depressive symptoms exacerbated this association; however, among men the relation between emotional eating and energy-dense snack foods was found only among men who did not exhibit depressive symptoms.

The COVID-19 pandemic has underscored the need to better understand the relationship between nutrition and stress so that we can better help people maintain their health during these highly stressful times.  If you are conducting research in this area, please consider publishing your research results in an ASN journal.  We’ll make sure your important findings are quickly disseminated around the world, helping to build a strong body of evidence to inform clinical practice and further research in this important and timely area of research.