Fruit and vegetable consumption and all-cause mortality: evidence from a large Australian cohort study

Abstract

Background: There is growing evidence for a relationship between fruit and vegetable consumption and all-cause mortality. Few studies, however, specifically explored consuming raw versus cooked vegetables in relation to health and mortality outcomes. The purpose of this study was to examine the relation of all-cause mortality with: a) fruit and vegetable consumption, either combined or separately; b) the consumption of raw versus cooked vegetables in a large cohort of Australian middle-aged and older adults.

Methods: The sample included 150,969 adults aged 45 years and over from the 45 and Up Study, a prospective cohort study conducted in New South Wales, Australia. Self-reported baseline questionnaire data (2006-09) were linked to mortality data up to June 2014. Fruit and vegetable consumption was assessed by validated short questions. Crude and adjusted hazard ratios were calculated using Cox proportional hazard models. Covariates included socio-demographic characteristics, health-related and dietary variables.

Results: During a mean follow-up of 6.2 years, 6038 (4 %) participants died from all causes. In the fully adjusted models, increasing consumption of fruit and vegetables combined was associated with reductions in all-cause mortality, with the highest risk reduction seen up to 7 serves/day or more of fruit and vegetables (P for trend = 0.002, hazard ratio for highest versus lowest consumption quartile: 0.90; 95 % confidence interval: 0.84, 0.97). Separate consumption of fruit and vegetables, as well as consumption of raw or cooked vegetables, were associated with a reduced risk of all-cause mortality in the crude and minimally adjusted models (all P for trend <0.05). With the exception of raw vegetables, these associations remained significant in the fully adjusted models (all P for trend <0.05). Age and sex were significant effect modifiers of the association between fruit and vegetable consumption and all-cause mortality.

Conclusions: Fruit and vegetable consumption were inversely related to all-cause mortality in this large Australian cohort. Further studies examining the effects of raw versus cooked vegetables are needed.