For decades, several national and international dietary guidelines emphasized consumption of vegetables and fruit as a component of a healthy diet. Many public health campaigns have therefore been launched to promote the importance of eating fruits and vegetables on a daily basis. Despite these efforts, our current fruit and vegetable intake remains suboptimal, particularly among low-income and vulnerable communities.
The level of fruit and vegetable intake conferring optimal protection against premature mortality or the development of chronic diseases remains an extremely important question. A team of well-known experts in nutritional epidemiology led by Dr. Frank B. Hu, member of the International Chair on Cardiometabolic Risk, has recently examined this issue and the results were reported in the AHA journal Circulation. The authors followed 66,719 women from the Nurses’ Health Study and 42,016 men from the Health Professionals Follow-up Study who were free from cardiovascular disease (CVD), cancer and diabetes at baseline. They also conducted a meta-analysis that included 26 studies with data on fruit and vegetable intake and mortality, including their own Nurses’ Health Study and the Health Professionals Follow-up Study.
The dose-response analysis of the association between fruit and vegetable intake and mortality risk revealed that the lowest mortality rate was observed with 5 servings of fruits and vegetables daily with no evidence of additional risk reduction provided by higher intakes. Similar conclusions were reached not only in the Nurses’ Health Study and the Health Professionals Follow-up Study but also in the large meta-analysis study which included 1,892,885 participants (145,015 deaths were recorded over the follow-up periods). Regarding cause-specific mortality, a threshold of approximately 5 daily servings was also associated with a lower risk of cancer mortality, CVD mortality and respiratory disease mortality, but no association was found with neurodegenerative disease mortality. Additional analyses also revealed that higher intakes of most fruit and vegetable subgroups were associated with a lower mortality risk, with the exception of higher intakes of starchy vegetables that were not associated with a lower mortality risk. Finally, fruit juice and potato intakes were not associated with total and cause-specific mortality.
These results confirm and support most of the current dietary recommendations to eat 5 portions of fruit (2 portions) and vegetables (3 portions) on a daily basis. The finding that no further benefits were observed above this threshold also has important public health implications. Indeed, the issue of equitable access to fruit and vegetables remains unsettled for the most vulnerable socioeconomic groups. With this paper, we hope that these groups, who have to cope with food insecurity, would be able to reach the optimal consumption target more easily.