This is according to researchers from the Friedman School of Nutrition Science and Policy at Tufts University, in Greater Boston, Massachusetts.

In a similar way to how doctors prescribe medications, clinicians and policymakers hope that by prescribing free, healthy foods, they can remove financial barriers preventing individuals with diet-related illness from accessing fruits and vegetables. Produce prescriptions offer vouchers, debit cards, or loyalty cards to access free or discounted produce at grocery retail and farmer’s markets, and, typically, these schemes enrol food-insecure households. A Tufts-led pooled analysis of nine such programmes found they were associated with positive benefits, from halving food insecurity to lowering blood pressure. The study, the largest known evaluation of these programmes to date, was published in the American Heart Association journal, Circulation: Cardiovascular Quality and Outcomes.

The researchers analysed surveys and medical records from more than 1800 children and 2000 adults who had been identified as low-income and at risk for cardiometabolic diseases. Study participants had been enrolled in produce prescription programmes operating across 22 sites in 12 US states, from 2014 to 2020. Each programme was operated by Wholesome Wave, a national non-profit 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. Diabetic patients, for example, saw a 0.3-percentage-point drop in haemoglobin 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-8mm 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 wellbeing.

“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 programmes, which may play a role in improving care, in particular for lower-income adults with obesity, diabetes, or hypertension.”

The records reviewed related to patients enrolled in the nine produce prescription programmes 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 programmes, and $112 per household per month in programmes for children.

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

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, reasons further: “There is much we still need to learn about which programmes are likely to be effective, how long they should operate, what happens to patient health outcomes when they end, and more.”

Alignment with national food and nutrition policy

Researchers across institutions have been conducting analyses of these and similar programmes, with most finding net-positive benefits for patients but differences in the extent of those gains and how the programmes were implemented. Such studies can help shape the implementation of the Biden-Harris Administration’s National Strategy on Hunger, Nutrition and Health, which, among other things, calls for expanded produce prescription programmes 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,” reflects Alison Brown, a registered dietitian and programme director in the Prevention and Population Science Program 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.”

Further research will help fill some existing information gaps. The new study, for example, lacked a control group, so the benefits could be attributed to other factors. Some of the programmes were also in place during the Covid-19 pandemic, which may have impacted their efficacy, as participants were less likely to redeem their vouchers.