Plant-based diet quality linked to lower Alzheimer's risk in later life

A large Multiethnic Cohort study published in Neurology followed about 93,000 adults for an average of 11 years and found associations between higher-quality plant-based diets and lower dementia risk, while less healthy plant-based patterns were linked to higher risk.

A new analysis in the journal Neurology examined how the quality of plant-based diets relates to Alzheimer’s disease and related dementias. The research used the Multiethnic Cohort, which includes participants from five racial and ethnic groups, and compared patterns of healthful and unhealthful plant-food consumption. Study authors also looked at changes in diet quality over time to see how shifting patterns related to later dementia risk. Experts who spoke with the article noted the study is observational and that further research was suggested. Study findings: - The study enrolled almost 93,000 adults with an average age of 59 from multiple racial and ethnic groups in the Multiethnic Cohort. - Participants completed food questionnaires and were scored on overall plant-food intake as well as on healthful versus unhealthful plant-based diet indices. - Over an average follow-up of 11 years, participants in the highest overall plant-food group had a 12% lower dementia risk compared with those in the lowest group. - When classified by plant-diet quality, the healthiest group had a 7% lower dementia risk and the unhealthiest plant-based group had a 6% higher dementia risk. - In a subset followed for about 10 years, participants who shifted toward a more unhealthful plant-based diet had a 25% higher dementia risk, while those who moved away from an unhealthful plant-based diet had an 11% lower risk. - The authors and interviewed clinicians noted that this was an observational study showing associations and called for intervention studies and further work on which dietary changes and interactions with other risk factors matter. Summary: The study reports associations between higher-quality plant-based eating patterns and lower rates of dementia, and between unhealthful plant-based patterns and higher rates. Researchers also found that changes in diet quality over time were linked to changes in dementia risk, and they recommend further intervention studies to test causality and to identify which specific dietary factors and interactions are most relevant.