A daily diet focused on fruits and vegetables has long been associated with living a longer, healthier life. However, it is less well-understood exactly how many of each is most protective against life-shortening conditions like heart disease and cancer.
A recent Harvard-led study that analyzed the diets of more than 2 million adults provides a more definitive answer. It shows that eating five daily servings – of which two are fruits and three are vegetables – may be the optimal combination for longevity.
A team of doctors and nutritionists analyzed data from two large, 30-year U.S. dietary studies that included more than 100,000 people. They combined the findings with those from 26 international studies encompassing nearly 2 million more participants from North and South America, Europe, Asia, Africa and Australia.
This massive amount of data showed that two fruit and three vegetable servings per day were associated with the greatest longevity. More than five daily servings, however, did not produce any additional benefit.
Compared to those in the study who consumed just two servings of fruit and vegetables per day, participants who consumed five servings had a 13% lower risk of death from all causes; a 12% lower risk of death from cardiovascular disease, including heart disease and stroke; a 10% lower risk of death from cancer; and a 35% lower risk of death from respiratory diseases such as chronic obstructive pulmonary disease (COPD).
Not all foods commonly thought of as being in the fruit and vegetable category were found to offer benefits, though. For example, starchy vegetables such as peas and corn, fruit juices and potatoes were not associated with reduced risk of chronic disease or of death. Green leafy vegetables like spinach and kale along with fruits and vegetables rich in beta carotene and vitamin C – such as citrus fruits, berries and carrots – were associated with the most life-extending benefits.
“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., an associate professor of medicine at Harvard Medical School. “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.”