Study suggests DASH diet may improve mental well-being in addition to lowering blood pressure

By Bhavana KunkalikarReviewed by Benedette Cuffari, M.Sc.May 3 2023

The Dietary Approaches to Stop Hypertension (DASH) diet has been shown to significantly lower blood pressure levels among hypertensive patients. However, despite available evidence supporting the beneficial effects of the DASH diet for physical health, only a few studies have examined the psychological effects of this diet.

In a recent study published in the journal Nutrition Reviews, researchers explore the effect of the DASH diet on mental well-being.

Study: Dietary Approaches to Stop Hypertension (DASH) diet and mental well-being: A systematic review. Image Credit: Wachiwit / Shutterstock.com

About the study

Between May 2021 and July 2021, researchers performed a thorough search for articles from PubMed, Web of Science, and PsycINFO databases. These databases were systematically searched up to May 2021.

The searched terms included dietary approaches to stop hypertension or DASH diet and mental health, depression, psychology, emotion, psychosocial, mood, anxiety, mental, quality of life, body image, eating disorders, affect, binge eating, bulimia, anorexia, eating disorders not otherwise specified, or EDNOS. 

Abstracts and titles of all searched articles were examined for eligibility. Studies that involved an intervention cohort of the DASH diet or a score estimating the compliance to the DASH diet estimated a minimum of one relevant outcome related to mental well-being, were interventional or observational studies, and were performed on human subjects were included in the current analysis.

Results

The final sample consisted of 16 studies, 10 observational studies and six randomized controlled trials (RCTs). Of the 10 observational studies, five were cross-sectional, four were longitudinal, and one was both cross-sectional and longitudinal. The sample size in the studies ranged from 36 to 19,270.

None of the RCTs assessed the incidence of clinically diagnosed depression. One observational study examined the correlation between DASH diet compliance and the development of clinically diagnosed depression by studying longitudinal information of healthy adult residents of Spain and controlling for sex, age, socioeconomic variables, total energy intake, health behaviors, weight alterations, and personality traits of dependency and competitiveness. A weak positive correlation was noted between incident depression and the Dixon DASH index.

A nonlinear and U-shaped association was observed between clinically diagnosed depression and Fung's, Gunther's, and Mellen's DASH diet indices. Medium compliance to the DASH diet estimated by these indexes was related to significantly lower hazard ratios of depression development.

When DASH diet compliance was divided into two groups of low and high adherence, only Fung's DASH index exhibited an inverse correlation with incident depression for less conservative and more conservative definitions.

One study revealed a negative correlation coefficient for the relationship between depressive symptoms and the DASH diet when examined by the Depression Anxiety Stress Scale-21 (DASS-21) without any covariate adjustment. Two RCTs noted that the DASH diet was associated with a positive effect on mood and emotions.

In one study wherein emotional symptoms were defined as "downhearted" and "unhappy" in comparison to their counterparts from the cohort, children from the DASH diet cohort exhibited significant improvements in their emotional symptoms after controlling for sociodemographic variables, energy consumption, baseline values, and parental education and occupation.

Studies that assessed the relationship between quality of life and the DASH diet revealed conflicting findings. Two RCTs noted that the DASH diet improved scores for the Subjective Symptoms Assessment Profile.

One study also reported that after the administration of the six-month intervention, DASH diet participants significantly enhanced their quality of life compared to their counterparts from the control cohort who consumed their usual diet.

Conclusions

The study findings showed that the DASH diet can have a positive influence on mental well-being. However, some findings were inconsistent, which could be accounted for by variations in assessment methods of the DASH diet and outcomes associated with mental health.

Future studies with effective methodological quality could verify the positive effects of the DASH diet on mental health, which, in turn, could help health practitioners design more comprehensive health techniques. A combination of nutritional and psychological perspectives is likely to improve overall well-being.