Self-reported dark chocolate consumption and depressive symptoms among community-dwelling older adults in Nagoya, Japan: a cross-sectional study

Introduction Evidence regarding the association between dark chocolate consumption and depressive symptoms remains limited, particularly among older adults. Objective To examine the association between self-reported dark chocolate consumption and depressive symptoms among community-dwelling older adults in Nagoya, Japan. Methods This cross-sectional study included 3,910 adults aged ≥ 70 years, of whom 2,957 were analyzed. Depressive symptoms were assessed using the Japanese version of the 15-item Geriatric Depression Scale (GDS-15-J). Dark chocolate consumption and depressive symptoms were assessed at the same study time point. Participants were classified into four groups: rare or no chocolate consumption, chocolate consumption without dark chocolate, dark chocolate consumption once or twice per week or more for ≤2 years, and dark chocolate consumption once or twice per week or more for >2 years. Logistic regression estimated odds ratios (ORs) and 95% confidence intervals (CIs) after adjustment of demographic, socioeconomic, lifestyle, and clinical covariates. Sensitivity analyses assessed robustness. Results Among the 2,957 participants, 48.4% were women, and the mean age was 78.0 ± 5.0 years. Dark chocolate consumption for >2 years was reported by 24.6%. In the fully adjusted model, participants reporting dark chocolate consumption for >2 years had lower estimated odds of depressive symptoms than those who reported rare or no chocolate consumption, although the confidence interval included the null (OR, 0.73; 95% CI, 0.53–1.01; p = 0.055). Multiple imputation yielded a similar estimate (OR, 0.69; 95% CI, 0.51–0.94; p = 0.020). Analyses restricted to participants with Mini-Mental State Examination (MMSE) scores ≥ 27 and ≥28 also yielded estimates in the same direction (OR, 0.66; 95% CI, 0.43–1.00; p = 0.051 and OR, 0.68; 95% CI, 0.42–1.12; p = 0.132, respectively). Among chocolate consumers, dark chocolate consumption for >2 years was associated with lower odds of depressive symptoms than chocolate consumption without dark chocolate (OR, 0.62; 95% CI, 0.43–0.88; p = 0.008). Conclusion Self-reported dark chocolate consumption for >2 years may be associated with lower odds of depressive symptoms among community-dwelling older adults in Nagoya, Japan. Prospective and interventional studies are needed to clarify the temporal and causal nature of this association.