In what is believed to be the largest study of these programs, researchers studied 3,881 people from low-income neighborhoods who received food vouchers through nine programs in a dozen states, from California to Florida. The participants received vouchers or cards worth $15 to $300 per month to buy more fruit and vegetables from farmers markets and grocery stores.
The research focused on how much produce adults and children ate before and after receiving the fruit and vegetable “prescription,” as well as measures of cardiovascular health, levels of food insecurity and their self-reported health status.
They found that adults who participated in the programs ended up eating about 30 percent more produce per day, according to the research published Tuesday in the journal Circulation: Cardiovascular Quality and Outcomes.
At the end of the programs, adults reported eating an average of 0.85 additional cups of fruits and vegetables per day. Children in the study ate 0.26 cups more — or about 7 percent more — than they did before the programs.
Most Americans don’t eat the recommended amount of fruits and vegetables per day, according to the Centers for Disease Control and Prevention. The U.S. Agriculture Department estimates a person would need to spend $63 to $78 per month to eat the recommended daily amount of fruit and vegetables. And a poor diet can lead to worse health over time.
“We have an ongoing epidemic of diet-related illness,” said Kurt Hager, an instructor at the University of Massachusetts’s T.H. Chan School of Medicine and the lead author of the study. “Physicians, historically, have had very few tools to improve the nutrition of their patients besides from some limited access to nutrition counseling.”
Based on the before-and-after comparison of participants, the size of the effect of more fruits and vegetables on blood pressure was “about half that of commonly prescribed medications, which is notable for a simple change in diet,” Hager said.
The adults and children in the programs either had or were at risk of developing heart disease or Type 2 diabetes, and they were enrolled either because they had been dealing with food insecurity — a lack of access to sufficient, nutritious food — or because they were recruited from a health center serving a low-income neighborhood. None of these programs has been studied or evaluated before. Each program lasted an average of six months and took place between 2014 and 2020.
Produce prescription programs have expanded in the past decade and especially in the past two to three years since the coronavirus pandemic. Existing studies on prescription produce programs showed vouchers for produce will get people to eat more fruits and vegetables, but it wasn’t clear whether eating more apples and carrots was associated with better health outcomes, such as lower blood pressure, Hager said.
“The covid-19 pandemic really underscored the high rates of diet-related illness in the U.S.,” Hager said. “Heart disease and diabetes became leading risk factors for covid-19 hospitalization and death.”
Still, more research is needed to determine whether fruits and vegetables actually contributed to better health for participants, Hager said. The study, which was funded by the Rockefeller Foundation and Kaiser Permanente, has some limitations. It did not include a control group and was not a randomized controlled trial, meaning other factors could have influenced the results. Because it was a retrospective review of the results of these programs, it is not clear whether the reported improvements in certain markers could have been because of other reasons.
It’s also not known if people had better health because they were eating more fruits and vegetables, or if the associated improvements in cardiometabolic health occurred because the money for fruits and vegetables addressed a household’s larger food insecurity. About 56 percent of the households in the study were experiencing food insecurity.
“These programs might work by removing the stress and anxiety of not knowing where your next meal is coming from,” Hager said. By the end of the programs, the odds of a household still being food insecure decreased by one-third.
Kevin G.M. Volpp, the director of the Center for Health Incentives and Behavioral Economics at the University of Pennsylvania, said studies like Hager’s cannot serve as proof that these programs lead to an improvement in blood pressure or blood sugar levels. “We really need randomized trials to answer that question more systematically,” Volpp said.
Eating a wide-ranging diet of fruits, vegetables, whole grains and legumes will probably improve your health. However, “we can’t really precisely estimate” how much produce someone should eat per day without more rigorous data, Volpp said.
Mitchell S.V. Elkind, the American Heart Association’s chief clinical science officer and a professor of neurology and epidemiology at Columbia University, called the study “a wonderful analysis” that suggests there are benefits to prescription produce programs. But researchers need to conduct a randomized trial, “just like you would do for a drug,” he said.
The journal Circulation is published by the American Heart Association.
The Rockefeller Association has funded a larger, “seven-to-10-year” initiative by the American Heart Association to conduct more research to determine whether “prescribing food” is a cost-effective way to manage and reduce the risk of these chronic conditions, Elkind said.
“If we don’t figure this out, our health-care costs are going to continue to skyrocket and we’ll continue to have some of the worst heart attacks, mortality rates and obesity rates in the world,” Elkind said. “We have to be better on this.”
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