Increased consumption of fruit and vegetables has been shown to be associated with a reduced risk of coronary heart disease (CHD) in many epidemiological studies, however, the extent of the association is uncertain. We quantitatively assessed the relation between fruit and vegetable intake and incidence of CHD by carrying out a meta-analysis of cohort studies. Studies were included if they reported relative risks (RRs) and corresponding 95% confidence interval (CI) of CHD with respect to frequency of fruit and vegetable intake. Twelve studies, consisting of 13 independent cohorts, met the inclusion criteria. There were 278,459 individuals (9143 CHD events) with a median follow-up of 11 years. Compared with individuals who had less than 3 servings/day of fruit and vegetables, the pooled RR of CHD was 0.93 (95% CI: 0.86-1.00, P=0.06) for those with 3-5 servings/day and 0.83 (0.77-0.89, P<0.0001) for those with more than 5 servings/day. Subgroup analyses showed that both fruits and vegetables had a significant protective effect on CHD. Our meta-analysis of prospective cohort studies demonstrates that increased consumption of fruit and vegetables from less than 3 to more than 5 servings/day is related to a 17% reduction in CHD risk, whereas increased intake to 3-5 servings/day is associated with a smaller and borderline significant reduction in CHD risk. These results provide strong support for the recommendations to consume more than 5 servings/day of fruit and vegetables.

Background Although it has been hypothesized that the diabetes-depression relation is bidirectional, few studies have addressed this hypothesis in a prospective setting. Methods A total of 65381 women aged 50–75 years in 1996 were followed until 2006. Clinical depression was defined as having diagnosed depression or using antidepressants, and depressed mood was defined as having clinical depression or severe depressive symptomatology, i.e., a Mental Health Index (MHI-5) score ≤52. Self-reported type 2 diabetes was confirmed using a supplementary questionnaire validated by medical record review. Results During 10-year follow-up (531097 person-years), 2844 incident cases of type 2 diabetes were documented. Compared to referents (MHI-5 score 86–100) who had the least depressive symptomatology, participants with increased severity of symptoms (MHI-5 score 76–85, 53–75, depressed mood) showed a monotonic elevated risk of developing type 2 diabetes (P for trend = 0.002). The relative risk (RR) for individuals with depressed mood was 1.17 (95% confidence interval [CI], 1.05–1.30) after adjustment for various covariates, and participants using antidepressants were at a particularly higher risk (RR, 1.25; 95% CI, 1.10–1.41). In a parallel analysis, 7415 incident clinical depression were documented (474722 person-years). Compared to non-diabetics, the RRs of developing clinical depression after controlling for all covariates were 1.29 (95% CI, 1.18–1.40) for diabetic patients, and 1.25, 1.24, 1.53 in diabetics without medications, with oral hypoglycemic agents, and insulin therapy, respectively (all P<0.01). These associations remained significant after adjustment for diabetes-related comorbidities. Conclusions Our results provide compelling evidence that the diabetes-depression association is bidirectional.

Background Caffeine is the world’s most widely used central nervous system stimulant, with about 80% consumed in form of coffee. However, studies that analyzed prospectively the relation of coffee or caffeine consumption and depression risk are scarce. Methods A total of 50,739 U.S. women (mean age=63 years) free from depressive symptoms at baseline (1996) were prospectively followed until 2006. Caffeine and coffee consumption, and other caffeinated and decaffeinated beverages, were obtained from validated questionnaires completed between 1980 through 2002 and computed as cumulative average of consumption with a 2-year latency applied. Clinical depression was defined as reporting both physician-diagnosed depression and antidepressant use. Relative risks of clinical depression were estimate using Cox proportional hazards regression models. Results During 10 years of follow-up (1996–2006), 2,607 incident cases of depression were identified. Compared to women consuming caffeinated coffee less frequently (≤1 cup/wk), multivariate relative risk of depression was 0.85 (95% confidence interval [CI], 0.75 to 0.95) for those consuming 2–3 cups/d and 0.80 (95%CI, 0.64 to 0.99; P trend <0.001) for those consuming ≥4 cups/d. Multivariate relative risk for depression was 0.80 (95%CI, 0.68 to 0.95; P trend=0.02) for women in the highest (≥550 mg/d) vs. lowest (<100 mg/d) of the 5 caffeine consumption categories. Decaffeinated coffee was not associated with depression risk. Conclusions In this large longitudinal study we found that depression risk decreases with increasing caffeinated coffee consumption. Further investigations are needed to confirm this finding and to determine whether usual caffeinated coffee consumption may contribute to depression prevention.

Although physical activity (PA) has been inversely associated with depressive symptoms, it is not clear whether regular PA and television watching are associated with clinical depression risk. The authors conducted a prospective analysis involving 49,821 US women from the Nurses' Health Study who were free from depressive symptoms at baseline (1996). Information on PA was obtained from validated questionnaires completed in 1992, 1994, 1996, 1998, and 2000; analyses were conducted using the cumulative average of PA (minutes/day) with a 2-year latency period applied. Participants were asked about television-watching habits in 1992. Cox proportional hazards regression models adjusted for multiple risk factors were used to estimate relative risks of clinical depression (self-reported physician-diagnosed depression or use of antidepressants). During 10 years of follow-up (1996-2006), 6,505 incident cases of depression were documented. Higher levels of PA were associated with lower depression risk. The multivariate relative risk comparing the highest level of PA (≥ 90 minutes/day) with the lowest (<10 minutes/day) was 0.80 (95% confidence interval: 0.70, 0.92; P(trend) < 0.001). In contrast, the risk of depression increased with increasing television-watching time. The multivariate relative risk comparing women who spent 21 hours/week or more watching television with those who spent 0-1 hour/week was 1.13 (95% confidence interval: 1.00, 1.27; P(trend) = 0.01). Analyses simultaneously considering PA and television watching suggested that both contributed independently to depression risk.

Objective Although it has been hypothesized that the depression-obesity relation is bidirectional, few studies have addressed this hypothesis in a prospective setting. We aimed to examine the bidirectional relationship in middle-aged and elderly women. Subjects A total of 65,955 women aged 54–79 years in the Nurses’ Health Study were prospective followed from 1996 to 2006 with updated information on body weight, depression status and various covariates every two years. Depression was defined as self-report of physician-diagnosed depression and/or antidepressant use. Obesity was defined as a body mass index ≥30.0 kg/m2. The first three waves (1996–2000) were used as the baseline period, and the last three waves (2002–2006) were used as the follow-up period. Results After adjusting for baseline age, physical activity, comorbidities, body mass index (BMI) and other covariates, depression at the baseline period was associated with an increased risk of obesity at the follow-up period in all women (multivariate-adjusted odds ratio [OR], 1.38; 95% CI, 1.24–1.53) and baseline non-obese women (OR, 1.51; 95% CI, 1.36–1.67). In the opposite direction, after adjusting for baseline age, physical activity, comorbidities, depression status and other covariates, obese women at baseline had a moderately increased risk of depression at the follow-up period compared with normal weight women (OR, 1.11; 95% CI, 1.03–1.18); and this association was similar for new onset of depression (OR for obese vs. normal weight women, 1.10; 95% CI, 1.02–1.20). Conclusions Our results suggest a bidirectional association between depression and obesity in middle-aged and elderly women. Future studies are needed to confirm our findings in different populations, and investigate the potential mechanisms underlying this association. Our results underscore the importance of early detection and proper behavioral modifications to lower the burden of both conditions.