Association between the food environment and the risk of ischemic stroke

A healthy diet is critical for stroke prevention. The role of the food environment is less clear. This study evaluated the association between the food environment and incident ischemic stroke in a large population-based study.

All first-ever ischemic strokes among residents of Nueces County, Texas from 2000-2023 were identified and geocoded by patient home address. The primary exposure was the modified retail food environment index (mRFEI), reflecting the mix of healthy and unhealthy food sources in each census tract (range 0-1, higher=healthier, modeled continuously), obtained from the National Neighborhood Data Archive. Population data were obtained from the US Census and American Community Survey. Stroke incidence rates were estimated using Poisson regression on cross-classified aggregate data. Covariates included age, sex, ethnicity, and neighborhood socioeconomic status (nSES).

A total of 6,716 first-ever ischemic strokes occurred in the study region from 2000-2023. Unexpectedly, higher (healthier) mRFEI values were associated with lower (poorer) nSES. Before adjustment, there was a marginal association between higher mRFEI scores and greater stroke incidence (incidence rate ratio [IRR] of 75^th vs 25^th percentile=1.07; 95%CI=0.99, 1.15; p=0.07). After adjustment, this association was attenuated and not statistically significant (IRR=1.00, 95%CI=0.95, 1.06; p=0.91). Post-hoc analyses evaluated healthy and unhealthy food sources separately and expanded the neighborhood to include adjacent tracts, yielding similar results.

No association was observed between the food environment and stroke incidence. These results add to a growing literature suggesting that improved access to healthy food sources alone may not be sufficient to reduce incidence of stroke and other cardiovascular events.