“While groups like the American Heart Association recommend four to five servings each of fruits and vegetables daily, consumers likely get inconsistent messages about what defines optimal daily intake of fruits and vegetables such as the recommended amount, and which foods to include and avoid,” said lead study author Dong D. Wang, M.D., Sc.D., an epidemiologist, nutritionist and a member of the medical faculty at Harvard Medical School and Brigham and Women’s Hospital in Boston.
It has been well documented that diets rich in fruits and vegetables help to reduce the risk of numerous chronic health conditions such as obesity, cardiovascular disease, and some cancers which are the leading causes of death. Despite this knowledge, according to the CDC, only 1 in 10 adults are eating enough fruits and vegetables.
For this study data from the Nurses’ Health Study and the Health Professionals Follow Up Study were analyzed, the reports followed over 100,000 people for up to 30 years, and they provided detailed information on the participant’s diets every 204 years. These results were compared with 26 additional studies involving about 1.9 million people across 29 nations examining the link between fruit and vegetable consumption and death.
Based on their findings the researchers suggest that 5 daily servings of fruits and vegetables appear to be the ideal number to promote longevity, with participants consuming 3 servings of vegetables and 3 servings of fruits daily having the longest lifespans.
Compared to those eating 2 servings of each daily, those eating the mix of 5 lowered their overall risk of premature death by 13%, risk of dying from heart disease decreased by 12%, risk of cancer decreased by 10%, and the risk of death from respiratory disease decreased by 35%.
No additional benefits were associated with consuming more than 5 servings, and not fruits and vegetables offered the same benefits. Starchy foods such as corn, potatoes, peas, and fruit juices were not associated with reduced risk of death from all causes or specific chronic diseases. Green leafy vegetables, fruits, and other vegetables rich in beta carotene and vitamin C showed the strongest benefits.
“Our analysis in the two cohorts of U.S. men and women yielded results similar to those from 26 cohorts around the world, which supports the biological plausibility of our findings and suggests these findings can be applied to broader populations,” Wang said.
Wang suggests that this study identified the evidence-based succinct public health message of the 5 a day mix as being an optimal intake of fruits/veggies. “This amount likely offers the most benefit in terms of prevention of major chronic disease and is a relatively achievable intake for the general public,” he said. “We also found that not all fruits and vegetables offer the same degree of benefit, even though current dietary recommendations generally treat all types of fruits and vegetables, including starchy vegetables, fruit juices and potatoes, the same.”
Due to the limited nature of observational studies this research can only show an association between fruit and vegetable consumption and the risk of death, it is not able to confer a direct cause and effect relationship.
“The American Heart Association recommends filling at least half your plate with fruits and vegetables at each meal,” said Anne Thorndike, M.D., M.P.H., chair of the American Heart Association’s nutrition committee and an associate professor of medicine at Harvard Medical School in Boston. “This research provides strong evidence for the lifelong benefits of eating fruits and vegetables and suggests a goal amount to consume daily for ideal health. Fruits and vegetables are naturally packaged sources of nutrients that can be included in most meals and snacks, and they are essential for keeping our hearts and bodies healthy.”
Co-authors are Yanping Li, Ph.D.; Shilpa N. Bhupathiraju, Ph.D.; Bernard A. Rosner, Ph.D.; Qi Sun, M.D., Sc.D.; Edward L. Giovannucci; Eric B. Rimm, Sc.D.; JoAnn E. Manson, M.D., M.P.H., Dr.P.H., FAHA; Walter C. Willett, M.D., Dr.P.H.; Meir J. Stampfer, M.D., Dr.P.H.; and Frank B. Hu, M.D., Ph.D.
The study was funded by the National Institutes of Health, the American Heart Association and the National Institute of Diabetes and Digestive and Kidney Diseases of the National Institutes of Health.
