Systematic review of observational studies has revealed that fish consumption and levels of n-3 polyunsaturated fatty acids (PUFAs) such as eicosapentaenoic acid (EPA) and docosahexaenoic acid are ...associated with a reduced risk of depression. A reverse J-shaped effect of n-3 PUFAs was suggested. However, there is limited evidence from populations with high fish consumption and no studies have used a standard psychiatrist-based diagnosis of major depressive disorder (MDD). Therefore, this population-based, prospective study investigated the association of dietary fish, n-3 PUFA, and n-6 PUFA consumption with risk of psychiatrist-diagnosed MDD in Japan. A total of 12 219 subjects were enrolled from the Saku area in 1990. Of these, we extracted 1181 participants aged 63-82 years who completed food frequency questionnaires in both 1995 and 2000 and also underwent a mental health examination in 2014-2015. Odds ratios (ORs) and 95% confidence intervals (CIs) for MDD according to fish intake and PUFA quartiles were calculated. Current MDD was diagnosed in 95 patients. We found a reduced risk of MDD in the third quartile for fish intake (111.1 g per day, OR=0.44, 95% CI=0.23-0.84), second quartile for EPA (307.7 mg per day, OR=0.54, 95% CI=0.30-0.99) and third quartile for docosapentaenoic acid (DPA) (123.1 mg per day, OR=0.42, 95% CI=0.22-0.85). ORs adjusted for cancer, stroke, myocardial infarction and diabetes remained significant for fish and DPA intake. Our results suggest that moderate fish intake could be recommended for the prevention of MDD in aged Japanese individuals.
Abstract
Background
In the general population, an increase in low-density lipoprotein cholesterol (LDL-C) predicts higher cardiovascular disease risk, and lowering LDL-C can prevent cardiovascular ...disease and reduces mortality risk. Interestingly, in cohort studies that include very old populations, no or inverse associations between LDL-C and mortality have been observed. This study aims to investigate whether the association between LDL-C and mortality in the very old is modified by a composite fitness score.
Methods
A 2-stage meta-analysis of individual participant data from the 5 observational cohort studies. The composite fitness score was operationalized by performance on a combination of 4 markers: functional ability, cognitive function, grip strength, and morbidity. We pooled hazard ratios (HR) from Cox proportional-hazards models for 5-year mortality risk for a 1 mmol/L increase in LDL-C. Models were stratified by high/low composite fitness score.
Results
Composite fitness scores were calculated for 2 317 participants (median 85 years, 60% females participants), of which 994 (42.9%) had a high composite fitness score, and 694 (30.0%) had a low-composite fitness score. There was an inverse association between LDL-C and 5-year mortality risk (HR 0.87 95% CI: 0.80–0.94; p < .01), most pronounced in participants with a low-composite fitness score (HR 0.85 95% CI: 0.75–0.96; p = .01), compared to those with a high composite fitness score (HR = 0.98 95% CI: 0.83–1.15; p = .78), the test for subgroups differences was not significant.
Conclusions
In this very old population, there was an inverse association between LDL-C and all-cause mortality, which was most pronounced in participants with a low-composite fitness scores.