Inverse Association between Fruit and Vegetable Intake and All-Cause Mortality: Japan Public Health Center-Based Prospective Study

Abstract

Background: A dose-response and nonlinear association between fruit and vegetable intake and mortality has been reported in Europe and the United States, but little is known about this association in Asia.

Objectives: This study aimed to evaluate the association of fruit and vegetable intake with all-cause, cancer, cardiovascular, and respiratory disease mortality in a Japanese cohort.

Methods: In the Japan Public Health Center-based prospective study, we included 94,658 participants (mean age: 56.4; 46.0% male) without cancer and cardiovascular disease at baseline. Information on fruit and vegetable intake was collected using a validated FFQ. The Cox proportional hazard model was used to estimate HRs and 95% CIs of each quintile of fruit and vegetable intake, separately, in relation to all-cause and cause-specific mortality using the first quintile as a reference. Nonlinear associations were evaluated using a likelihood ratio test, comparing a linear model with a restricted cubic spline model.

Results: During a median of 20.9 follow-up years (IQR: 19.6-23.8 y), 23,687 all-cause deaths were documented. After adjusting for age, sex, and potential confounding factors, fruit and vegetable intake was nonlinearly and significantly associated with lower all-cause mortality, with the fourth and fifth quintiles having comparable HRs (fruit: fourth quintile HR: 0.91; 95% CI: 0.87, 0.95 and fifth quintile HR: 0.92; 95% CI: 0.88, 0.96; P-nonlinearity < 0.001; vegetable: fourth quintile HR: 0.92; 95% CI: 0.88, 0.97 and fifth quintile HR: 0.93; 95% CI: 0.89, 0.98; P-nonlinearity = 0.002). Fruit intake was significantly associated with lower cardiovascular mortality (HR in the fifth quintile: 0.91; 95% CI: 0.83, 0.99; P-nonlinearity = 0.01).

Conclusions: In the Japanese population, higher intake of fruits and vegetables was nonlinearly associated with decreased all-cause mortality. These findings may contribute to the establishment of dietary recommendations for enhancing life expectancy in Asia.

Keywords: epidemiology; fruit intake; life expectancy; mortality; vegetable intake.