Association between consumption of fruits and vegetables in midlife and depressive symptoms in late life: the Singapore Chinese Health Study

Abstract

Objectives: Epidemiological evidence of how midlife intake of fruits and vegetables affects the likelihood of depressive symptoms in late life remains limited and controversial. We examined this association in an Asian cohort.

Design: Prospective population-based cohort study.

Setting: Chinese living in Singapore.

Participants: A total of 13,738 adults from the Singapore Chinese Health Study.

Measurements: The consumption of 14 fruits and 25 vegetables were assessed using a validated 165-item food-frequency questionnaire at baseline (1993-1998), when participants were aged 45-74 years (mean age 52.4 years). Depressive symptoms were evaluated using the Geriatric Depression Scale during the third follow-up interviews (2014-2016), when participants were aged 61-96 years (mean age 72.5 years), and depression was defined by ≥5 out of 15 scores. Multivariable logistic regression models were used to calculate odds ratios (ORs) and 95% confidence intervals (CIs).

Results: After a mean follow-up of 19.6 years, depressive symptoms were identified among 3,180 participants. Consumption of fruits was inversely associated with the odds of depressive symptoms in a dose-response manner: comparing extreme quartiles, the OR (95% CI) of depressive symptoms was 0.71 (0.63-0.81; P-trend <0.01). Intake of several types of fruits, especially orange, tangerine, banana, papaya and watermelon, was associated with reduced odds, and this inverse association was similar across subgroups of fruits categorized by glycemic index. Conversely, intake of vegetables was not associated with the odds of depressive symptoms.

Conclusions: Our findings support population-based recommendation of having sufficient fruit intake early in life to reduce the likelihood of depressive symptoms in late life.

Keywords: Asian; Cohort study; Depression; Fruit; Vegetable.

Fig. 1

Dose-response associations of intake quantity of fruits and vegetables with depressive symptoms in late life, the Singapore Chinese Health Study. Notes: Covariates in the restricted cubic spline regression model were the same as in the final models of Table 2. Panel A. Linear inverse association was observed for fruit intake (P-overall <0.01, P-nonlinearity = 0.10) and the OR (95% CI) per SD increment of fruit intake was 0.86 (0.82−0.91); P <0.01). Panel B. Neither linear nor nonlinear association was observed for vegetable intake (P-overall = 0.16, P-nonlinearity = 0.08).

Fig. 2

Multivariable-adjusted ORs and 95% CIs of depressive symptoms for different types of fruits, the Singapore Chinese Health Study. All models were adjusted for age at the third follow-up, sex, dialect group, level of education, marital status at the third follow-up, body mass index, cigarette smoking, alcohol drinking, dietary intake of red meat and vegetables, total energy intake, physical activity, sleep duration, baseline medical history of hypertension, diabetes, cardiovascular diseases, and instrumental limitations, self-rated health, and social activity at the third follow-up. Serving size was referred to the United States Department of Agriculture's (USDA) National Nutrient Database (http://ndb.nal.usda.gov).