Background
Despite findings from cross-sectional studies, how food insecurity experience/Supplemental Nutrition Assistance Program (SNAP) status relates to cognitive decline over time has not been fully understood.

Objectives
We aimed to investigate the longitudinal associations between food insecurity/SNAP status and cognitive function in older adults (≥65 y).

Methods
Longitudinal data from the National Health and Aging Trends Study 2012–2020 were analyzed (n = 4578, median follow-up years = 5 y). Participants reported food insecurity experience (5-item) and were classified as food sufficient (FS, no affirmative answer) and food insufficient (FI, any affirmative answer). The SNAP status was defined as SNAP participants, SNAP eligible nonparticipants (
200% Federal Poverty Line, FPL), and SNAP ineligible nonparticipants (>200% FPL). Cognitive function was measured via validated tests in 3 domains, and the standardized domain-specific and combined cognitive function z-scores were calculated. Mixed-effect models with a random intercept were used to study how FI or SNAP status was associated with combined and domain-specific cognitive z-scores over time, adjusting for static and time-varying covariates.

Results
At baseline, 96.3% of the participants were FS and 3.7% were FI. In a subsample (n = 2832), 10.8% were SNAP participants, 30.7% were SNAP eligible nonparticipants, and 58.6% were SNAP ineligible nonparticipants. Compared with the FS group in the adjusted model (FI vs. FS), FI was associated with faster decline in the combined cognitive function scores [−0.043 (−0.055, −0.032) vs. −0.033 (−0.035, −0.031) z-scores per year, P-interaction = 0.064]. Cognitive decline rates (z-scores per year) in the combined score were similar in SNAP participants (β = −0.030; 95% CI: −0.038, −0.022) and SNAP ineligible nonparticipants (β = −0.028; 95% CI: −0.032, −0.024), both of which were slower than the rate in SNAP eligible nonparticipants (β = −0.043; 95% CI: −0.048, −0.038; P-interaction < 0.0001).

Conclusions
Food sufficiency and SNAP participation may be protective factors preventing accelerated cognitive decline in older adults.

https://www.sciencedirect.com/science/article/pii/S0022316622132578