Fruit and Vegetable Intake and Mortality: Results From 2 Prospective Cohort Studies of US Men and Women and a Meta-Analysis of 26 Cohort Studies
Dong D. Wang, Circulation Mar 2021
BACKGROUND: The optimal intake levels of fruit and vegetables for
maintaining long-term health are uncertain.
METHODS: We followed 66719 women from the Nurses’ Health Study
(1984–2014) and 42016 men from the Health Professionals Follow-up Study
(1986–2014) who were free from cardiovascular disease (CVD), cancer, and
diabetes at baseline. Diet was assessed using a validated semiquantitative
food frequency questionnaire at baseline and updated every 2 to 4 years.
We also conducted a dose-response meta-analysis, including results from
our 2 cohorts and 24 other prospective cohort studies.
RESULTS: We documented 33898 deaths during the follow-up. After
adjustment for known and suspected confounding variables and risk
factors, we observed nonlinear inverse associations of fruit and vegetable
intake with total mortality and cause-specific mortality attributable to
cancer, CVD, and respiratory disease (all Pnonlinear<0.001). Intake of ≈5
servings per day of fruit and vegetables, or 2 servings of fruit and 3
servings of vegetables, was associated with the lowest mortality, and
above that level, higher intake was not associated with additional risk
reduction. In comparison with the reference level (2 servings/d), daily
intake of 5 servings of fruit and vegetables was associated with hazard
ratios (95% CI) of 0.87 (0.85–0.90) for total mortality, 0.88 (0.83–0.94)
for CVD mortality, 0.90 (0.86–0.95) for cancer mortality, and 0.65 (0.59–
0.72) for respiratory disease mortality. The dose-response meta-analysis
that included 145015 deaths accrued in 1892885 participants yielded
similar results (summary risk ratio of mortality for 5 servings/d=0.87 [95%
CI, 0.85–0.88]; Pnonlinear<0.001). Higher intakes of most subgroups of fruits
and vegetables were associated with lower mortality, with the exception
of starchy vegetables such as peas and corn. Intakes of fruit juices and
potatoes were not associated with total and cause-specific mortality.
CONCLUSIONS: Higher intakes of fruit and vegetables were associated
with lower mortality; the risk reduction plateaued at ≈5 servings of
fruit and vegetables per day. These findings support current dietary
recommendations to increase intake of fruits and vegetables, but not fruit
juices and potatoes.
