Research Clarifies Optimal Mix of Fruit, Vegetable Servings for Sustained Health

March 8, 2021
Jill Murphy, Associate Editor

According to the study, diets rich in fruits and vegetables help reduce the risk for numerous chronic health conditions that are leading causes of death, including cardiovascular disease and cancer.

Studies representing nearly 2 million adults worldwide found that eating about 5 daily servings of fruits and vegetables, in which 2 are fruits and 3 are vegetables, is likely the optimal amount for a longer life, according to new research published in the American Heart Association journal Circulation.

According to the study, diets rich in fruits and vegetables help reduce the risk for numerous chronic health conditions that are leading causes of death, including cardiovascular disease and cancer. However, approximately 1 in 10 adults eat enough fruits or vegetables, as reported by the CDC.

“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, MD, ScD, an epidemiologist, nutritionist and a member of the medical faculty at Harvard Medical School and Brigham and Women’s Hospital in Boston, in a press release.

Wang and his team analyzed data from the Nurses’ Health Study and the Health Professionals Follow-Up Study, which included more than 100,000 adults who were followed for up to 30 years. Both datasets included detailed dietary information repeatedly collected every 2 to 4 years. Further, for this analysis, researchers also pooled data on fruit and vegetable intake and death from 26 studies that included approximately 1.9 million participants from 29 countries and territories in North and South America, Europe, Asia, Africa, and Australia.

The analysis revealed that intake of approximately 5 servings of fruits and vegetables daily was associated with the lowest risk of death, whereas eating more than 5 servings was not associated with additional benefit. Further, eating approximately 2 servings daily of fruits and 3 servings daily of vegetables was associated with the greatest longevity.

Compared to those who consumed 2 servings of fruit and vegetables per day, participants who consumed 5 servings a day of fruits and vegetable 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 disease, such as chronic obstructive pulmonary disease (COPD), according to the study authors.

However, not all foods that one might consider to be fruits and vegetables offered the same benefits. For example, starchy vegetables, fruit juices, and potatoes were not associated with reduced risk of death from all causes or specific chronic diseases. On the other hand, green leafy vegetables and fruit and vegetables rich in beta carotene and vitamin C showed benefits.

“Our analysis in the two cohorts of US 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 in a press release.

Wang added that this study identifies an optimal intake level of fruits and vegetables and supports the evidence-based, succinct public health message of “5-a-day,” meaning people should ideally consume 5 servings of fruit and vegetables each day.

“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,” Wang said in a press release. “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.”

Further, a limitation of the research is that it is observational, showing an association between fruit and vegetable consumption and risk of death, as it does not confer a direct cause-and-effect relationship, according to the study authors.

“The American Heart Association recommends filling at least half your plate with fruits and vegetables at each meal,” said Anne Thorndike, MD, MPH, 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.”

REFERENCE

The right ‘5-a-day’ mix is 2 fruit and 3 vegetable servings for longer life. American Heart Association. https://newsroom.heart.org/news/the-right-5-a-day-mix-is-2-fruit-and-3-vegetable-servings-for-longer-life. Published March 1, 2021. Accessed March 2, 2021.