Produce Prescription Programs Yield Positive Health Benefits for Participants CREDIT Alonso Nichols/Tufts University

Around the country, non-profits and local governments are testing the idea of food as medicine through “produce prescription programs”—with promising results, according to researchers from the Friedman School of Nutrition Science and Policy at Tufts University.

By prescribing free, healthy foods similar to how doctors prescribe medications, clinicians and policy makers hope to remove financial barriers to accessing fruits and vegetables to individuals with diet-related illness. Specifically, produce prescriptions offer vouchers, debit cards, or loyalty cards to access free or discounted produce at grocery retail and farmer’s markets and typically enroll food-insecure households. A Tufts-led pooled analysis of nine such programs found these programs were associated with positive benefits, from halving food insecurity to lowering blood pressure. The study, which is the largest known evaluation of these programs to date, was published August 29 in the American Heart Association journal Circulation: Cardiovascular Quality and Outcomes.

The researchers analyzed surveys and medical records from over 1,800 children and 2,000 adults who had been identified as low-income and at risk for cardiometabolic diseases. Study participants had been enrolled in produce prescription programs operating across 22 sites in 12 U.S. states from 2014 to 2020. Each program was operated by Wholesome Wave, a national nonprofit that works to address disparities in diet-related disease and enhance nutrition equity by making fruits and vegetables more accessible and affordable to low-income community members through systems change.

The data showed an increase in fruit and vegetable intake (by about a serving per day among adults) as well as improved clinical biomarkers of cardiometabolic health for adults. For example, diabetic patients saw a 0.3 percentage point drop in hemoglobin A1C, an indicator for average blood sugar levels in the previous three months, and a decrease in body mass index by 0.4 kg/m² among those with overweight or obesity. In patients with hypertension, blood pressure also dropped by 5-to-8 millimeters of mercury. The improvement for these clinical biomarkers of cardiometabolic health were greater among participants with uncontrolled diabetes, obesity, or stage 2 hypertension.  

The study also revealed improvements in fruit and vegetable intake, food security, and self-reported health status among child participants. While body mass index was not noticeably reduced in children, the researchers say these benefits reflect critical measures for their development, long-term health and well-being.

“We were excited to see the results, which showed that participants who receive this incentive consume more fruits and vegetables, yielding clinically relevant outcomes,” says senior study author Fang Fang Zhang, a nutritional epidemiologist and Neely Family Professor at the Friedman School. “We need larger-scale implementation of these programs, which may play a role in improving care, in particular for lower-income adults with obesity, diabetes, or hypertension.”

The records reviewed were from patients who were enrolled in the nine produce prescription programs for an average of six months, usually after being referred by their physician. Most participants received a voucher or card that could be redeemed at selected grocery stores and/or farmers’ markets. Prescriptions covered an average of $43 per household per month in adult programs, and $112 per household per month in programs for children.

“Our findings provide important new evidence from a diverse set of programs for meaningful benefits of produce prescriptions, highlighting the need for clinical, policy, and healthcare payer and providers’ efforts to implement produce prescription programs,” says Zhang.

“There is much we still need to learn about which programs are likely to be effective, how long they should operate, what happens to patient health outcomes when they end and more,” says first author Kurt Hager, who completed the work as a doctoral student at the Friedman School and is now an instructor at the University of Massachusetts Chan Medical School. “The future of Food is Medicine will likely see pilots and expansion occurring alongside ongoing evaluations that will continually improve the quality of services provided.”

Researchers across institutions have been conducting analyses of these and similar programs, with most finding net positive benefits for patients, but differences in the extent of those gains and how the programs were implemented. Such studies can help to guide the implementation of the Biden-Harris Administration’s National Strategy on Hunger, Nutrition and Health, which, among other things, calls for expanded produce prescription programs for people enrolled in Medicaid, Medicare, Veterans Affairs, and the Indian Health Service.

“This research is a step in the right direction and in alignment with the comprehensive National Strategy on Hunger, Nutrition, and Health,” says Alison Brown, a registered dietician and program director in the Prevention and Population Science Program in the Division of Cardiovascular Sciences at the National Heart, Lung, and Blood Institute, part of the National Institutes of Health. “However, more rigorous ‘food is medicine’ studies are needed to add to our scientific knowledge and inform evidence-based policies.”

Extreme dietary habits for carbohydrates and fats affect life expectancy: findings from a large-scale cohort study in Japan CREDIT Reiko Matsushita

A new study, published in The Journal of Nutrition, suggests that extreme dietary habits involving carbohydrates and fats affect life expectancy. Researchers from Nagoya University Graduate School of Medicine in Japan led by Dr. Takashi Tamura found that a low carbohydrate intake in men and a high carbohydrate intake in women are associated with a higher risk of all-cause and cancer-related mortality and that women with higher fat intake may have a lower risk of all-cause mortality. Their findings suggest that people should pursue a balanced diet rather than heavily restricting their carbohydrate or fat intake. 

While low-carbohydrate and low-fat diets are becoming popular as a way to promote weight loss and improve blood glucose levels, their long-term effects on life expectancy are less clear. Interestingly, recent studies conducted in Western countries suggest that extreme dietary habits for carbohydrates and fats are associated with a higher risk of mortality. However, few studies have explored these associations in East Asian populations, including Japanese individuals who typically have relatively low fat and high-carbohydrate dietary intakes. 

The authors conducted a follow-up survey over a period of 9 years with 81,333 Japanese people (34,893 men and 46,440 women) to evaluate the association between carbohydrate and fat intakes and the risk of mortality. Daily dietary intakes of carbohydrates, fats, and total energy were estimated using a food frequency questionnaire and calculated as a percentage of total energy intake for carbohydrates and fats. Carbohydrate intake quality (i.e., refined compared with minimally processed carbohydrate intake) and fat intake quality (i.e., saturated compared with unsaturated fat intake) were also assessed to examine the impact of food quality on the association with mortality. 

They found that men who consumed less than 40% of their total energy from carbohydrates experienced significantly higher risks of all-cause and cancer-related mortality. The trend was observed regardless of whether refined or minimally processed carbohydrate were considered. On the other hand, among women with 5 years or longer of follow-up, those with a high carbohydrate intake of more than 65% had a higher risk of all-cause mortality. No clear association was observed between refined or minimally processed carbohydrate intake and the risk of mortality in women. 

For fats, men with a high fat intake of more than 35% of their total energy from fats had a higher risk of cancer-related mortality. They also found that a low intake of unsaturated fat in men was associated with a higher risk of all-cause and cancer-related mortality. In contrast, total fat intake and saturated fat intake in women showed an inverse association with the risk of all-cause and cancer-related mortality. They concluded that this finding does not support the idea that high fat intake is detrimental to longevity in women.  

“The finding that saturated fat intake was inversely associated with the risk of mortality only in women might partially explain the differences in the associations between the sexes,” Dr. Tamura stated. “Alternatively, components other than fat in the food sources of fat may be responsible for the observed inverse association between fat intake and mortality in women.” 

This study is extremely important because restricting carbohydrates and fats, such as extremely low-carbohydrate and low-fat diets, are now popular dieting strategies aimed at improving health, including the management of metabolic syndrome. However, this study shows that low-carbohydrate and low-fat diets may not be the healthiest strategy for promoting longevity, as their short-term benefits could potentially be outweighed by long-term risk.  

Overall, an unfavorable association with mortality was observed for low-carbohydrate intake in men and for high carbohydrate intake in women, whereas high fat intake could be associated with a lower mortality risk in women. The findings suggest that individuals should carefully consider how to balance their diet and ensure that they are taking in energy from a variety of food sources, while avoiding extremes. 

Research Highlights:

• Adults at risk for heart disease who participated in produce prescription programs for an average of six months increased their consumption of fruits and vegetables and had reduced blood pressure, body mass index and blood sugar levels.
• Among adults and children, produce prescription programs also appeared to decrease food insecurity — the lack of equitable and stable availability, access, affordability and consumption of healthy foods and drinks — and improve self-reported health status.

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People at increased risk for cardiovascular disease who participated in produce prescription programs increased their consumption of fruits and vegetables, which was associated with improved body mass index (BMI), blood sugar and blood pressure levels, as well as a decrease in food insecurity. This new research was published today in Circulation: Cardiovascular Quality and Outcomes, a peer-reviewed American Heart Association journal.

Produce prescription programs enable doctors to prescribe fruits and vegetables in addition to medications. Patients receive electronic cards or vouchers to access free or discounted produce of their choice at retail grocery or farmers’ markets, explained study lead author Kurt Hager, Ph.D., M.S., an instructor at UMass Chan Medical School in Worcester, Massachusetts.

Although previous research has examined the effects of small, individual produce prescription programs, this analysis is believed to be the largest produce prescription study by pooling data from nine programs across the U.S. to assess health outcomes after about six months.

“We know that food insecurity impacts health through several important pathways, including overall dietary quality, but also through stress and anxiety, mental health and tradeoffs between paying for food and other basic needs such as housing costs, utilities and medications,” said Hager, who completed these analyses while a doctoral student at the Friedman School of Nutrition Science and Policy at Tufts University in Boston. “These results indicate produce prescriptions may lay an important foundation for improved health and well-being.”

Study participants received a median of $63 per month to purchase produce at local stores and farmers markets. In addition, participants attended nutrition classes. At the beginning and after completing the program — which ranged from 4 to 10 months— participants completed questionnaires about fruit and vegetable consumption, food insecurity and health status. Routine testing of blood pressure; weight and height; and hemoglobin A1c (HbA1c) -a measure of blood sugar – was completed at enrollment and at the conclusion of the program. The study did not include a control group and compared outcomes among participants before and after program participation.

The analysis of all participants found:

• Adults reported that their intake of fruits and vegetables increased by nearly one cup per day (0.85 cups per day). Among children, intake of fruits and vegetables increased by about a quarter of a cup per day (0.26 cups per day).
• Systolic blood pressure — blood pressure during heartbeats — decreased more than 8 millimeters of mercury (mm Hg); while diastolic blood pressure — blood pressure between heartbeats — decreased nearly 5 mm Hg among adults who had high blood pressure at enrollment in the study.
• Blood sugar, as measured by HbA1C levels, decreased by 0.29 to 0.58 percentage points among adults with diabetes.
• BMI significantly improved, with a reduction of 0.52 kilograms per square meter (kg/m2) among adults with obesity. Among children, however, BMI did not change.
• Adults were 62% more likely and children were more than twice as likely to report better health status by program completion.
• Overall, participants were one-third less likely to report food insecurity after completing the programs compared to before the programs.

“Poor nutrition and nutrition insecurity are major drivers of chronic disease globally, including cardiometabolic conditions like Type 2 diabetes and their cardiovascular consequences, including heart failure, heart attack and stroke,” according to Mitchell Elkind, M.D., M.S., FAHA, chief clinical science officer of the American Heart Association and a tenured professor of neurology and epidemiology at Columbia University. “This analysis of produce prescription programs illustrates the potential of subsidized produce prescriptions to increase consumption of nutritious fruits and vegetables, reduce food insecurity and, hopefully, improve subjective and objective health measures. Future research will need to include randomized controlled trials to offset any potential bias and prove more rigorously the benefits of produce prescription programs. The American Heart Association’s new Food Is Medicine Initiative will be focused on supporting such trials.”