Five servings a day lower the risk
Increased consumption of fruit and vegetables has been recommended as a key component of a healthy diet for the prevention of chronic diseases
In recent years, there has been growing evidence that fruit and vegetable consumption is related to mortality, including mortality from cardiovascular disease and cancer. The results, however, are not entirely consistent.
In this new study Dr. Frank Hu, MD, PhD, Departments of Nutrition and Epidemiology, Harvard School of Public Health, Boston, and Dr. Wei Bao, MD, PhD, postdoctoral fellow, Epidemiology Branch, Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Rockville along with colleagues from China and the U.S. , examined the association between fruits and vegetables and risk of all cause, cardiovascular, and cancer mortality and the dose relationship.
Researchers searched Medline, Embase, and the Cochrane library through August 30, 2013 for prospective cohort studies hat reported risk estimates for all cause, cardiovascular, and cancer mortality by levels of fruit and vegetable consumption.
The researchers had examined 16 studies that included 833.234 participants
During the follow-up period from 4.2 to 26 years there were 56,423 deaths (11,512 from heart disease and 16,817 from cancer) among the participants. Higher consumption of fruit and vegetables was associated with a lower risk of all-cause mortality.
The researchers found five servings of fruits and vegetables were associated to the reduced risk. The average risk reduction from all causes was reduced by 5% for each additional serving and 4% for cardiovascular death.
There was a threshold around five servings of fruit and vegetables a day, after which the risk of all-cause mortality did not reduce further. Higher consumption of fruit and vegetables was not appreciably associated with risk of cancer mortality.
In their conclusion the researchers write “This meta-analysis provides further evidence that a higher consumption of fruit and vegetables is associated with a lower risk of all-cause mortality, particularly cardiovascular mortality.” “The results support current recommendations to increase consumption to promote health and overall longevity.”
The researchers note there were limitations to this study including that the inverse association between fruit and vegetable consumption and mortality could be related to a generally more healthy diet and lifestyle.
This study is published in BMJ's Journal of Epidemiology and Community Health.
Citation; BMJ 2014;349:g4490