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

Abstract

ImportanceFood 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.ObjectiveTo determine whether food insecurity is associated with a faster decline in cognitive function among community-dwelling older adults.Design, Setting, and ParticipantsThis 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.ExposuresSelf-reported food insecurity assessed from 2012 to 2019.Main Outcomes and MeasuresPrimary 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.ResultsOf 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 RelevanceAmong 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.

Associations of Food Insecurity and Memory Function Among Middle to Older–Aged Adults in the Health and Retirement Study

“…This finding is consistent with and contributes to the nascent literature examining the association between food insecurity and cognition in middle to older–aged adults; although relatively small in magnitude, the observed association is consistent in direction with results from 3 longitudinal studies linking food insecurity to faster cognitive decline, 16 , 17 , 19 including memory decline. 16 , 17 There are several pathways through which this association may develop.…”

“…Covariates of interest included time-invariant baseline confounders measured in 1998 and time-varying confounders that were recorded at each wave and time-updated between 1998 and 2016. Based on earlier literature, 10 , 11 , 12 , 16 , 17 , 18 , 19 , 36 , 37 , 38 , 39 these confounders were hypothesized to affect both food insecurity status and cognitive function and decline; we used a directed acyclic graph to specify our assumptions regarding the associations between confounders, food insecurity exposure, and memory over time ( Figure 1 ). As shown in the directed acyclic graph, we posited the existence of exposure-confounder feedback whereby the time-varying confounders are both influenced by exposure to food insecurity at one time point and affect food insecurity status at a later time point.…”

“… 3 Among middle to older–aged adults, research on food insecurity and health is relatively scarce, 4 although earlier evidence has shown food insecurity to be associated with various physical and mental health outcomes, 4 , 5 , 6 , 7 , 8 , 9 including cognition. 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 As population aging accelerates, understanding the association between food insecurity and brain health among older adults is a national public health priority. 20 …”

“…To date, most research on food insecurity and cognition in middle to older–age adults has examined this association using cross-sectional data and has suggested that food insecurity is associated with poorer global cognition and lower performance on assessments of executive function and memory 10 , 11 , 12 ; by comparison, very few studies in adults have examined this association longitudinally. 16 , 17 , 18 , 19 For example, a longitudinal study of Puerto Rican adults aged 49 to 75 years living in Boston, Massachusetts, reported that food insecurity was associated with a significantly faster 2-year decrease in global cognition and executive function, and a smaller and nonsignificant decrease in memory function. 17 More recently, in a cohort of US adults older than 65 years with 9 years of follow-up, food insufficiency at baseline was associated with a faster annual decrease in global cognition and immediate and delayed recall, but not executive function.…”

“… 18 In the only study, to our knowledge, to examine both food insecurity status and cognition longitudinally, community-dwelling Medicare beneficiaries (aged ≥65 years) who were food insecure at any visit during a 7-year follow-up period had a faster decrease in executive function, but not memory, compared with those who were always food secure. 19 …”