Recently, nutrition scientists have begun to explore how nutrition not only affects physical health, but also mental health through a variety of complex pathways and mechanisms.  The American Society for Nutrition (ASN) journals have been at the forefront of this research.  While the following articles shed new light on our understanding of the link between nutrition and mental health, for immediate assistance in a crisis, call 911. It is important to take care of your mental health and seek support if you need it.

Find additional mental health resources from the National Institutes of Health (NIH) here.

The American Journal of Clinical Nutrition

Randomized trials should be undertaken to examine whether diets rich in low-glycemic index foods could serve as treatments for depression.

Published June 2015, “High Glycemic Index Diet as a Risk factor for Depression: Analyses from the Women’s Health Initiative” ranks among the top 5% of all research outputs scored by Altmetric.  Working with data collected over a three-year period from participants in the Women’s Health Initiative Observational Study, ASN member James E. Gangwisch et al. sought to discover the relationship between dietary glycemic index, glycemic load, and other carbohydrate measures with depression among postmenopausal women.

The authors found a “progressively higher dietary glycemic index to be associated with increasing odds of depression incidence in carefully controlled analyses.”  In particular, they noted that added sugars, but not total sugars or total carbohydrates, were strongly associated with the incidence of depression, perhaps because these added sugars have a higher glycemic index than sugars found naturally in food.  Based on their findings, the authors believe “randomized trials should be undertaken to examine the question of whether diets rich in low-glycemic index foods could serve as treatments and primary preventive measures for depression in postmenopausal women.”

The Journal of Nutrition

When female volunteers were dehydrated, vigor, fatigue, and aggregate mood were adversely affected.

Severe dehydration results in acute confusion and delirium; however, ASN member Lawrence E. Armstrong et al. wanted to know if mild dehydration at levels that may occur in healthy individuals during their ordinary daily activities might also degrade cognitive performance, alter mood, or produce other adverse symptoms.  To conduct their research, the authors recruited 25 women who participated in three 8-hour activities designed to induce mild dehydration.  A placebo control group was also recruited for comparison.  The results, published in “Mild Dehydration Affects Mood in Healthy Young Women,” indicate that “when female volunteers, at rest or during exercise, were dehydrated (mean loss of 1.36% body mass), vigor, fatigue, and aggregate mood, assessed by total mood disturbance score, were adversely affected.”  Interestingly, while mild dehydration negatively affected the mood of study participants, the authors did not see any significant decline in their cognitive performance.

Advances in Nutrition

Polyphenol consumption has the potential to lower the risk of developing depression as well as alleviate depressive symptoms.

Scientific reviews concur that a Mediterranean diet may have the potential to reduce depressive symptoms.  Jessica Bayes et al. set out to review whether the reduction in depressive symptoms might be due to the abundance of polyphenol-rich foods found in a Mediterranean diet, including berries, fruits and whole grains, publishing their findings in “Effects of Polyphenols in a Mediterranean Diet on Symptoms of Depression: A Systematic Literature Review.”  Following a comprehensive literature search, the authors identified 37 studies that met their criteria, including 17 experimental studies and 20 observational studies.  Of these studies, 29 found “a statistically significant effect of polyphenols for depression.”  Moreover, the authors found that polyphenol consumption not only had the potential to lower the risk of developing depression, they also found evidence suggesting polyphenols can effectively alleviate depressive symptoms.  Calling for additional research, the authors underscored the lack of studies on young adults and men, which “limits the relevance of these findings to a broader audience.”

Current Developments in Nutrition

Findings suggest that maternal prenatal stress can be an important risk factor for suboptimal fetal iron stores.

A 2020 study, “Maternal Prenatal Psychosocial Stress and Pre-pregnancy BMI Associations with Fetal Iron Status,” sheds new light on a possible link between the mental health of mothers and the nutritional status of their babies.  Working with a cohort of 493 pregnant women, ASN member Rebecca K. Campbell et al. determined that prenatal psychosocial stress and psychological dysfunction, including the experience of traumatic life events, depression and anxiety, were associated with lower fetal iron stores at birth.  These findings corroborated the results of two prior studies that reported associations between prenatal stress and fetal iron status.  According to the authors, “our findings suggest that maternal prenatal stress, especially when combined with excess pre-pregnancy BMI, can be an important risk factor for suboptimal fetal iron stores, with possible implications for fetal and early childhood neurocognitive development.”

As more research is conducted into the link between nutrition and mental health, the findings from these studies may help to develop nutritional guidelines that support better mental health.  If you are conducting research that examines the relationship between nutrition and mental health, please consider submitting your findings for publication in an ASN journal for dissemination around the world.