Scientific Study

Background & aims: Evidence on the association between nut consumption and depression is mainly based on cross-sectional studies. This study aims to analyse whether nut consumption is prospectively associated with the risk of depression in adults. Methods: This study was conducted using the United Kingdom (UK) Biobank resource. Data from middle-aged and older UK adults who participated in this cohort between 2007-2012 (baseline) and 2013-2020 (follow-up) were analysed. Baseline information on nut consumption was obtained with the Oxford WebQ 24-h questionnaire. Depression, defined as a self-reported physician diagnosis of depression or antidepressant use, was assessed at baseline and follow-up. Hazard regression models estimating the predictive ability of nut consumption for the risk of developing depression were adjusted for sociodemographic, lifestyle, and health confounders. Results: A total of 13,504 participants (mean age 57.5 ± 7.2 years, 50.7% female) free of depression at baseline were included in the analyses. After a mean follow-up of 5.3 ± 2.4 years, 1122 (8.3%) incident cases of depression were identified. Compared with no nut consumption, the daily consumption of >0 to 1 serving of 30 g of nuts was associated with a lower risk of depression (hazard ratio, HR = 0.83; 95% confidence interval, CI: 0.71-0.97) regardless of all potential confounders considered. In stratified analyses, a decreased risk of depression was more clearly observed in UK adults with adequate weight control, a healthy lifestyle, and better health status than in their counterparts (p < 0.05). Conclusions: Low-to-moderate nut consumption (>0 to 1 serving of 30 g/day) was associated with a 17% lower risk of depression during a 5.3-year follow-up compared with no nut consumption in a large sample of middle-aged and older UK adults. This protective association is enhanced in the absence of other known risk factors for depression. https://doi.org/10.1016/j.clnu.2023.07.020