Folsom, CA—A new epidemiological study suggests that consuming walnuts may be associated with a lower prevalence and frequency of depression symptoms among American adults, according to a press release from the California Walnut Commission.
The press release says that after evaluating study participants for depression, researchers found that depression scores were 26% lower for walnut consumers and 8% lower for consumers of other nuts, compared to those who did not consumer any nuts.
For the study—titled “Lower Depression Scores among Walnut Consumers in NHANES”—researchers examined data from the National Health and Nutrition Examination Survey, which draws from a large sampling of the U.S. population. More than 26,000 American adults were asked about their dietary intake over the course of one to two days and depression symptoms over the previous two weeks. The release says that participants ranked how often they experienced factors such as irregular sleep, feeling tired, and trouble concentrating. Walnut consumers were more likely to have greater interest in activities, higher energy levels, less hopelessness, better concentration, and greater optimism.
Results were obtained after controlling for age, sex, race, income, BMI, smoking, alcohol consumption, and marital status, the release says. On average, walnut consumers ate just under a ¼ cup serving.
Dr. Lenore Arab of the David Geffen School of Medicine at the University of California, Los Angeles, said in the release, “According to the CDC, one out of every six adults will have depression at some time in their life. It is important to find low-cost interventions, such as dietary changes, that are easy to implement and may help reduce the incidence of depression. Walnuts have previously been investigated for their role in cardiovascular and cognitive health, and now we see an association with depression symptoms—providing another reason to include them in a healthy eating plan.”
The release noted that participants were only asked about dietary choices over the course of a couple days, which may not be representative of usual consumption patterns. Depression can change typical appetite and eating patterns, confounding cause and effect. And because of the cross-sectional nature of the study, the findings cannot prove causality.