More and more, consumers are looking for foods beneficial to overall wellness, including both body and mind.1 This comes at a time when the CDC recognizes that almost one in twelve adults have suffered from depression in a given two-week period,2 making it imperative to find accessible strategies, like dietary changes, that can positively impact this condition. Fortunately, there is growing evidence supporting certain foods, like walnuts, for their potential beneficial role in cognitive factors like memory and mental health conditions such as depression.
A new epidemiological study suggests consuming walnuts may be associated with a lower prevalence and frequency of depression symptoms among American adults.3 After evaluating study participants for depression, researchers found depression scores were 26 percent lower for walnut consumers and eight percent lower for consumers of other nuts, compared to those who did not consume nuts at all.
Researchers examined data on over 26,000 American adults from the National Health and Nutrition Examination Survey (NHANES), which draws from a large sampling of the U.S. population. Findings based upon a widely-accepted questionnaire, revealed depression scores to be significantly lower among those who consumed nuts, particularly walnuts, compared to those who did not consume nuts, even after controlling for age, sex, race, income, BMI, and other lifestyle factors. Average intake among consumers was approximately 24 grams or just under one quarter cup of walnuts per day (typical serving size is 1 ounce). Researchers found those who ate walnuts were more likely to have greater interest in activities, higher energy levels, less hopelessness (among women), better concentration, and greater optimism. While an association between nut consumption and depression scores existed for both men and women, the findings suggest the benefit may be more prevalent among women.
Findings from this study contribute to the growing body of published research exploring the potential role of walnuts in cognitive health. While outcomes from the project provide a basis for future research on foods that may have an impact on mental health, it is important to consider the limitations. Due to the cross-sectional nature of the study, the findings cannot prove causality. Depression may also change typical appetite and eating behaviors resulting in apparent associations that are not causal. In addition, participants were asked about their dietary choices over the course of one to two days, which may not be representative of usual consumption patterns.
When compared to other tree nuts, walnuts have a unique fatty acid profile. They contain mostly polyunsaturated fats, including a significant amount of the plant-based omega-3 alpha-linolenic acid (2.5 g/oz), which is more than any other nut. Check out this collection of simple snacks to feel satisfied and fueled throughout the day.
1 California Walnuts Attitude & Usage Survey of 3,032 Americans 18-55 years, Edelman Intelligence, April 2017.
2 Brody DJ, Pratt LA, Hughes J. Prevalence of depression among adults aged 20 and over: United States, 2013–2016. NCHS Data Brief, no 303. Hyattsville, MD: National Center for Health Statistics. 2018.
3 Arab L, Guo R, Elashoff D. Lower Depression Scores among Walnut Consumers in NHANES. Nutrients. 2019;11(2):275. doi.org/10.3390/nu11020275
