Non-alcoholic beverage consumption and risk of depression: epidemiological evidence from observational studies

Recent epidemiological studies have examined associations between various types of non-alcoholic beverage consumption and risk of depression, but the associations were inconsistent. To provide a quantitative assessment of this association, we performed a systematic review and meta-analysis of observational studies.

We searched PubMed and Web of Science databases through February 2017 for eligible studies and examined the reference lists of the retrieved articles. A random-effects model was used to calculate pooled relative risks (RR) with 95% CIs after adjusting for important confounders.

We identified fifteen observational studies (9 cross-sectional studies; 6 prospective studies) of beverage consumption and depression, including 20,572 cases of depression among 347,691 participants. For coffee and tea consumption, the pooled RRs of depression for the high vs. low categories of consumption were 0.73 (95% CI 0.59-0.90) and 0.71 (95% CI 0.55-0.91), respectively. For soft drinks, however, the pooled RR for the high vs. low category of consumption was 1.36 (95% CI 1.24-1.50). The inverse association with coffee or tea consumption and the positive association with soft drink consumption for risk of depression did not vary by gender, country, high consumption category, and adjustment factors such as alcohol, smoking and physical activity.

Our findings suggest that high consumption of coffee and tea may reduce the risk of depression, while high consumption of soft drinks may increase the risk of depression. Further well-designed large prospective studies are needed to provide definitive evidence to address the effects of various types of beverages on risk of depression.