Food Insecurity and Cognitive Trajectories in Community-Dwelling Medicare Beneficiaries 65 Years and Older.

IMPORTANCE: Food insecurity has a known association with prevalent impaired cognition. However, it is unknown whether food insecurity has a longitudinal association with cognitive decline among older adults.

OBJECTIVE: To determine whether food insecurity is associated with a faster decline in cognitive function among community-dwelling older adults.

DESIGN, SETTING, AND PARTICIPANTS: This retrospective cohort study used data from a nationally representative sample of Medicare beneficiaries 65 years and older recruited for the National Health and Aging Trends Study (NHATS). Community-dwelling NHATS participants were followed up for a maximum of 7 years (mean [SD] follow-up duration, 5.4 [1.1] years). Data were collected from January 1, 2012, to December 31, 2020, and analyzed from December 23, 2021, to December 6, 2022.

EXPOSURES: Self-reported food insecurity assessed from 2012 to 2019.

MAIN OUTCOMES AND MEASURES: Primary outcomes were immediate memory, delayed memory, and executive function collected from 2013 to 2020. Immediate and delayed recall were assessed by a 10-item word-list memory task (range, 0-10, with higher scores indicating more words recalled). Executive function was measured by the clock drawing test (range, 0-5, with higher scores indicating more accurate depiction of a clock). Each year's cognitive functions were linked to the prior year's food insecurity data. Linear mixed-effects models with random slopes and intercepts were used to examine the association between food insecurity and cognitive decline. Analytic weights in each year were applied to represent community-dwelling Medicare beneficiaries 65 years and older in 2011.

RESULTS: Of 3037 participants, a weighted 57.8% (raw count, 1345) were younger than 75 years, 56.2% (raw count, 1777) were women, and most (84.9% [raw count, 2268]) were White. Over 7 years, 417 (weighted proportion, 12.1%) experienced food insecurity at least once. Food insecurity was associated with a faster decline in executive function in a fully adjusted model: the mean difference of annual change in executive function score between people exposed to and not exposed to food insecurity was -0.04 (95% CI, -0.09 to -0.003) points. However, food insecurity was not associated with changes in immediate and delayed memory (0.01 [95% CI, -0.05 to 0.08] and -0.01 [95% CI, -0.08 to 0.06], respectively).

CONCLUSIONS AND RELEVANCE: Among community-dwelling older adults, food insecurity was prevalent and associated with a decline in executive function. Interventions and policies aiming to increase healthy food access or reduce food insecurity should be assessed for their impact on older adults' cognitive outcome.