Background: Nut intake has been associated with lower mortality, but few studies have investigated causes of death other than cardiovascular disease, and dose-response relationships remain unclear.
Methods: We investigated the relationship of nut (tree nut, peanut) and peanut butter intake with overall and cause-specific mortality. In the Netherlands Cohort Study, 120,852 men and women aged 55-69 years provided information on dietary and lifestyle habits in 1986. Mortality follow-up until 1996 consisted of linkage to Statistics Netherlands. Multivariate case-cohort analyses were based on 8823 deaths and 3202 subcohort members with complete data on nuts and potential confounders. We also conducted meta-analyses of our results with those published from other cohort studies.
Results: Total nut intake was related to lower overall and cause-specific mortality (cancer, diabetes, cardiovascular, respiratory, neurodegenerative diseases, other causes) in men and women. When comparing those consuming 0.1-<5, 5-<10 and 10+ g nuts/day with non-consumers, multivariable hazard ratios for total mortality were 0.88, 0.74 and 0.77 [95% confidence interval (CI), 0.66-0.89], respectively (Ptrend = 0.003). Cause-specific hazard ratios comparing 10+ vs 0 g/day varied from 0.56 for neurodegenerative to 0.83 for cardiovascular disease mortality. Restricted cubic splines showed nonlinear dose-response relationships with mortality. Peanuts and tree nuts were inversely related to mortality, whereas peanut butter was not. In meta-analyses, summary hazard ratios for highest vs lowest nut consumption were 0.85 for cancer, and 0.71 for respiratory mortality.
Conclusions: Nut intake was related to lower overall and cause-specific mortality, with evidence for nonlinear dose-response relationships. Peanut butter was not related to mortality.
Keywords: Nuts; cohort studies; mortality; neoplasms; peanuts; respiratory tract diseases.
© The Author 2015; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association.