Research Finds Food Swamps May Increase Stroke Risk in Older Adults

New research has found that living near a “food swamp”—an area with a higher density of fast food and junk food options rather than healthy options—may increase the risk of stroke in adults 50 years of age and older.

The term “food swamp” originated more than a decade ago to define communities where fast-food chains and convenience stores are the dominant sources of food, as opposed to grocery stores or places with healthy food options. Food swamps often coincide with food deserts, where a lack of grocery stores makes it more difficult to get produce and nutritious foods.

“Despite major advances in stroke care, stroke continues to be a significant problem, and some people will remain at risk despite optimal medical treatment,” said lead author Dixon Yang, MD, in a press release. “An unhealthy diet negatively impacts blood pressure, blood glucose, and cholesterol levels that increases the risk of stroke. Independent of one’s own demographics or socioeconomic status, living in a neighborhood with an abundance of poor food choices may be an important factor to consider for many people.”

A 2022 policy statement by the American Heart Association urged policies that ensure nutrition security for all people across their lifespan, including education and tools to prepare, eat, and store nutritious foods. According to the policy statement, the availability, accessibility, and affordability of nutritious foods is not equitable in the United States, with 12.8% of the population having both lower income and limited access to a grocery store, supermarket, or supercenter in 2015.

The potential association between food swamps and stroke is not well understood. In the current study, the authors analyzed whether food swamp environments might be associated with greater odds of stroke by reviewing data from the Health and Retirement Study. These data were then cross-referenced with food environment information from the US Department of Agriculture to derive a retail food environment index (RFEI), which indicates the ratio of fast food restaurants and convenience stores to the number of retail healthy food options within neighborhoods.

The study included 17,875 adults with an average age of 64 years, 54% of whom were women, and 84% of whom were white. Statistical weighting was applied to represent the general US population. Two categories were created for the retail food environment index—a ratio lower than 5 or a ratio of 5 or more.

“The two categories were chosen for comparison because prior research has shown that a retail food environment index ratio of 5 or higher may predict the prevalence of people with obesity in a neighborhood,” Yang said in the press release.

Of those studied, 3.8% self-reported that they had had a stroke. The analysis found that 28% of people lived in an area with a RFEI score below 5, while 72% lived in areas ranked as 5 or higher on the index. Those in the higher RFEI group had 13% higher odds of incident stroke compared to those who lived in neighborhoods with an index score below 5.

The overall median RFEI across all communities was a ratio of 6. Yang noted that this means many participants lived in an area with 6 times the amount of unhealthy to healthy food retailers.

“Our research highlights the potential importance of an area’s retail food options as a structural factor affecting stroke, especially since most participants resided in areas with 6 times the amount of relative unhealthy to healthy food choices,” Yang said in the press release.

Notably, however, the study was limited by its cross-sectional design, which captured only a single period of time. Therefore, researchers were unable to prove cause and effect between retail food environment index and stroke. In addition, stroke was self-reported and there was no information on type of stroke.

“At this early stage of our research, it’s important to raise awareness that a person’s neighborhood and food environment are potentially important factors affecting their health, especially among people who may have difficulty in reaching optimal cardiovascular health targets,” Yang said in the press release. “In the future, it may help to focus on community-based interventions or dietary guidance to improve cardiovascular health, thereby hopefully reducing the risk of stroke.”

REFERENCE

Living near a “food swamp” may increase stroke risk among adults 50 and older. News release. American Heart Association; February 2, 2023. Accessed February 7, 2023. https://newsroom.heart.org/news/living-near-a-food-swamp-may-increase-stroke-risk-among-adults-50-and-older?preview=6fa7