In a March 2022 Scientific Note, reported the World Health Organization, “The COVID-19 pandemic has had a severe impact on the mental health and well-being of people around the world while raising concerns about increased suicidal behaviors. “. Specifically, the WHO noted that “the COVID-19 pandemic resulted in a 27.6% increase in cases of major depressive disorder and a 25.6% increase in cases of anxiety disorders globally in 2020” . Additionally, “women were more affected than men, and young people, especially those between the ages of 20 and 24, were more affected than older adults.”
Not all people with mental disorders respond well to traditional pharmaceutical and psychological treatments. In fact, 30-40% of people with depression do not find sufficient relief with pharmacological or psychological treatment. In response, the American Society for Nutrition (ASN) has encouraged research into the link between nutrition and mental health for many years. Additionally, these studies indicate the role that nutrition may play in maintaining good mental health as well as in managing mental health disorders. Below are highlights of original research studies and reviews published in the four ASN journals that are leading to a better understanding of nutrition and mental health.
The effect of a Mediterranean diet on symptoms of depression in young men (the “AMMEND study: a Mediterranean diet in men with depression”): a randomized controlled trial, The American Journal of Clinical NutritionApril 2022
Jessica Bayes, ASN member et al. conducted a 12-week randomized controlled trial to assess the effect of a Mediterranean diet in the treatment of moderate to severe depression in 72 men, aged 18-25. The participants, all of whom had been diagnosed with major depressive disorder, were divided into two groups: a dietary intervention group and a control group. The dietary intervention group attended a 60-minute nutritional counseling appointment led by a clinical nutritionist who offered personalized dietary advice, goal setting, and mindful eating strategies to support adherence to the Mediterranean diet. They also received information on portion sizes, sample meal plans, recipes, dining options and a daily online eating history survey. In contrast, participants in the control group attended supportive “friendship” sessions in which the researchers discussed neutral topics of interest such as movies, sports, and hobbies. Friendship support was chosen for its ability to control for factors that may confound the results of randomized controlled trials. At the end of the study, the authors determined that the diet intervention group experienced “significant improvements in depressive symptoms with no observed side effects.” Specifically, the authors observed a mean reduction of 20.6 points on the Beck Depression Inventory Scale – Version II in the dietary intervention group compared to a reduction of 6.2 points for the group witness.
Chronic stress and unhealthy eating behaviors among low-income African American caregivers, Current developments in nutritionMarch 2020
Working with data collected over four years as part of the Detroit Dental Health Project, Sungwoo Lim et al. assessed the association between chronic stress and unhealthy eating behaviors in 912 low-income African American caregivers in Detroit, Michigan. The average caregiver was 28 years old and raising two children. About half of the caregivers had a household income of less than $10,000 and did not have a high school diploma. Sixty-six percent of caregivers said they experienced discrimination a few times a month or more. Twenty-five percent of caregivers reported an unhealthy diet characterized by excessive consumption of high-fat foods and carbonated drinks. The authors believe that this unhealthy diet was “significantly associated with chronic stress”, as caregivers with chronic stress were more than twice as likely to consume an unhealthy diet. Moreover, “nearly 41% of this association was explained by an indirect route through depressive symptoms”. In summary, the authors believe their research “provides evidence for developing a more targeted intervention to promote healthy eating behaviors among chronically stressed minority caregivers.”
Persistent food insecurity is associated with mental health problems among women living with or at risk of HIV in the United States, The Nutrition DiaryFebruary 2019
Emily L. Tuthill et al. investigated the association between food insecurity and depression among women participating in the Women’s Interagency HIV Study, a prospective cohort study of women at risk of or living with HIV in the United States. The 2,551 study participants, with an average age of 48, completed 6 biannual food security and mental health assessments. Using multiple regression analysis, the authors estimated the association between these variables. The results of the study indicate that “food insecurity, particularly when persistent, was associated with more depressive symptoms, increased risk of probable depression, and poor mental well-being in women infected with HIV and at risk”. Specifically, women with persistent food insecurity had a depression score 6.86 points higher than women with intermittent food insecurity or no food insecurity, according to the Center for Epidemiologic Studies Depression Scale, which assesses depressive symptoms on a scale of 0 to 60. The authors call for the “development of multilevel programs and intervention strategies guided by a syndemic orientation…to optimize the health of HIV-infected and at-risk women” .
The role of gut microbiota in dietary interventions for depression and anxiety, Advances in nutritionMarch 2020
Nutrition scientists have studied diet and mood as well as the microbiome-gut-brain axis, which examines the influence of the gut microbiota on neurobiology and behavior, with the aim of developing treatment strategies for mental health disorders that could complement traditional pharmaceutical and psychological strategies. . According to ASN member Tracey LK Bear et al. “Because diet has a great influence on the composition and function of the gut microbiota, it is likely that changes in the gut microbiota contribute to how diet (whole diet and individual diet components) can affect the depression and anxiety.” The authors of this review further note that “limited research in this area is sometimes contradictory, and primarily in rodents, but shows a pattern of findings indicating that the gut microbiota may play an important role and should be considered in dietary intervention studies”. The authors also believe that there may be critical developmental windows during which the gut microbiota has the greatest effect on mental health, such as in early life, adolescence and during gestation.
As these studies suggest, there is a two-way relationship between nutrition and mental health: just as nutrition can affect mental health, mental health can affect nutrition. We invite you to explore the full collection of ASN journals to learn more about nutrition and mental health to support your own research or clinical practice. Keyword searches using terms such as ‘depression’, ‘anxiety’ or ‘mental health’ will lead you to a range of original and relevant research studies and reviews.