Researchers suggest that people in the U.S. who are a part of the SNAP program may be at greater risk of all-cause and cardiovascular mortality.
Study leader Zach Conrad, Ph.D. - former postdoctoral fellow at the Friedman School of Nutrition Science and Policy at Tufts University in Medford, MA - and colleagues report their findings in the American Journal of Public Health.
SNAP is a food assistance program overseen by the U.S. Department of Agriculture (USDA).
Formerly known as the Food Stamps Program, SNAP offers food-purchasing assistance to individuals and families with a low income - defined as a gross monthly salary at or below 130 percent of the federal poverty line.
In 2015, the federal government spent approximately $75 billion on SNAP, helping around 1 in 6 low-income U.S. individuals to purchase food.
According to the USDA, SNAP is "the nation's first line of defense against hunger and offers a powerful tool to improve nutrition among low-income people."
Food items that are eligible for purchase with SNAP benefits include fruits, vegetables, meats, fish, poultry, breads, cereals, and dairy products, as well as plants and seeds that produce edible foods.
SNAP participants cannot use their benefits to purchase alcohol, cigarettes, or tobacco. However, "junk food" - such as soft drinks, candy, and cookies - can be purchased, since the 2008 Food and Nutrition Act defines eligible food as "any food or food product for home consumption."
Mortality risk increased twofold for SNAP participants
For their study, Conrad and colleagues analyzed data from the 2000-2009 National Health Interview Survey, which provided health information on 499,741 U.S. adults aged 25 and older.
The researchers set out to investigate the differences in mortality between three groups: individuals who took part in SNAP between 2000-2009, people who were eligible for SNAP benefits (based on income) but who did not participate in the program, and those who were ineligible for SNAP.
The survey data were linked to information on all-cause and cardiovascular mortality, provided by the Centers for Disease Control and Prevention (CDC).
Compared with individuals who were ineligible for SNAP, those who participated in SNAP were found to have a twofold greater risk of all-cause and cardiovascular mortality, and a threefold increased risk of diabetes mortality, over the 10-year period.
The risk of all-cause and cardiovascular mortality was 1.5 times higher for individuals who were eligible for SNAP but who did not participate, compared with ineligible adults, while the risk of diabetes mortality was almost twofold higher.
Looking at the data by race and ethnicity, the team found that the increased risk for all-cause and cardiovascular mortality was similar in both white and black individuals who took part in SNAP. Hispanics who participated in the program, however, were found to have a significantly lower mortality risk than that of other racial and ethnic groups.
The increased risk of diabetes mortality for SNAP participants was similar across all races and ethnicities, the team reports.
SNAP participants 'require greater support to improve health'
The study findings remained after accounting for a number of possible confounding factors, including age, body mass index (BMI), physical activity, smoking status, alcohol use, and insurance coverage.
However, the team found that differences in employment, education, and marital status between each of the three groups could partly explain the differences in mortality.
While the study is purely observational and cannot prove that SNAP participation is a direct cause of increased mortality risk, the researchers say that their findings indicate that more needs to be done to boost the health of SNAP participants.
"Our results suggest that the millions of low-income Americans who rely on SNAP for food assistance require even greater support to improve their health than they currently receive. Such efforts should be a priority for policymakers.
Mortality differences were consistent by age and gender, whereas racial and ethnic differences were more varied. This highlights the need for further careful investigation of the underlying drivers of the observed poor health, which can help guide improvements to the program."
Senior study author Dr. Dariush Mozaffarian, Friedman School of Nutrition Science and Policy
The team notes that SNAP participants tend to have a lower quality of diet than those who do not participate in the program, which can contribute to poor health.
Changing financial incentives for foods purchased under the SNAP program could be one way to improve participants' diets, the researchers suggest. They point out that state-level modifications to the SNAP program have shown that offering financial incentives can increase the consumption of healthful foods.
"SNAP is effective at reaching a population that is at increased risk of ill health," says Conrad. "Given that approximately 15 percent of the U.S. population participates in this important food assistance program, it is a vital component of the nation's public health programming infrastructure, and strategies to improve the health of its participants must be prioritized."