Is food insecurity among older adults associated with higher subsequent dementia risk and memory decline?

By Dr. Liji Thomas, MDNov 22 2023Reviewed by Danielle Ellis, B.Sc.

There are approximately 6 million Americans aged 65 years or over who have Alzheimer's disease and Alzheimer's disease–related dementias (AD/ADRD); this number is expected to shoot up to 14 million, more than double the current total by 2060.

Food insecurity is also on the rise in American households, being reported in more than 7% of those harboring older people in 2021, up from 5% two decades ago. Moreover, estimates project that almost a tenth of people in their sixth decade will experience food insecurity. This is associated with higher risks of malnutrition, poor health, metabolic and cardiovascular disease, stress, depression, and dementia.

Programs like the Supplemental Nutrition Assistance Program (SNAP) are being run to alleviate food insecurity. Since dementia is essentially incurable at present and is inevitably progressive, the current research published in JAMA Network Open sought to identify the presence of a link between food insecurity and dementia using longitudinal data and compensating for other variables that may vary over the course of life. This could help strengthen food security programs to reduce the risk of elderly dementia.

The study included Americans aged at least 50 years from the US Health and Retirement Study. There were over 7,000 participants, all of whom had reported issues with food security in 2013 and who had data on their cognitive levels from studies conducted between 2014 and 2018.

The food security responses were used to classify the participants as anywhere between food secure and very low food secure. The memory score and the risk of dementia were estimated every two years using an appropriately framed and tested algorithm.

The mean age was 68 years, with about 60% being women. About 16% were Black, and two-thirds were White. The average level of education was found to be equivalent to 13 years of schooling.

What did the study show?

Almost a fifth of the participants were not food secure, with 10% and 8% being low and very low food secure, respectively. Among those aged 65 or more at the start of the study, the level of food insecurity was relatively lower at 11%, vs 28% of those below 65.

Food insecurity was more likely to be present also among women, Blacks, or Hispanics with less education and lower incomes. They were more likely to be on welfare and to rent their homes and less likely to be married.

The results of the study indicated that dementia risk was higher among the least food-secure, with the odds being more than a third higher compared to the food-secure group (~37% higher). In other words, food insecurity increases the risk of dementia at any age to that expected at an age 1.3 years later.

Moreover, both low and very low food security were linked to poorer memory at age  70, equivalent to being older by 0.7 and 1 more year for low and very low food insecurity, respectively. There was also a slightly increased pace of memory loss with age.

What are the implications?

The study obviously points to the potential for an association of increased dementia risk and lower memory levels with lower food security, along with a more rapid decline in memory over time. Further research is essential to validate these results and look at the place of food security interventions in preserving and improving cognitive function in aging people.

The data support the impact of the economic recession between 2007 and 2009 among older Americans, leading to increased food insecurity. In addition, it underlines the common risk of dementia and food insecurity in poorer Black or Hispanic communities, and more so among unwed women, emphasizing the effects of social and economic characteristics on health in later life.

Paradoxically, less than half of eligible older people use SNAP, as shown by earlier research, compared to 86% overall, though this may be related to lower levels of cognitive function. Making it easier to apply for and avail of such programs might be a big step towards promoting higher uptake of this program, especially in this subgroup.

"Our findings highlight the need to improve food security in older adults and that doing so may protect individuals from cognitive decline and dementia."