Study Links High-Quality Plant-Based Diets to Lower Dementia Risk in Large Cohort

A study published on October 23, 2024, in the journal Neurology examined the relationship between plant-based diets and the risk of Alzheimer's disease and related dementias. The research involved 92,933 participants from the Multiethnic Cohort Study, tracked for an average of 11 years, with an average starting age of 59.

Participants included African American, Japanese American, Latino, Native Hawaiian, and white individuals.

Researchers assessed three dietary patterns: overall plant food consumption without regard to quality; a healthful plant-based index featuring whole grains, fruits, vegetables, vegetable oils, nuts, legumes, tea, and coffee; and an unhealthy plant-based index including refined grains, fruit juices, potatoes, and added sugars.

The study did not specifically evaluate vegetarian or vegan diets. Dietary data were collected via self-reported questionnaires.

the follow-up period, 21,248 participants developed dementia.

Individuals consuming the highest amounts of overall plant foods had a 12% lower risk of dementia compared to those consuming the least. For the healthful plant-based index, the highest adherence group showed a 7% lower risk. In contrast, those with the highest adherence to the unhealthy plant-based index faced a 6% higher dementia risk compared to the lowest group.

Analysis of dietary changes over a decade revealed that shifting toward unhealthy plant foods was associated with a 25% higher dementia risk, while moving away from such foods correlated with an 11% lower risk.

The study has limitations, including reliance on self-reported dietary data, which may involve recall inaccuracies.

It establishes associations but does not prove causation, and factors like physical activity or other health conditions were not fully controlled. Future research could explore mechanisms linking specific plant foods to brain health. Dr.

Song-Yi Park, lead author from the University of Hawaii at Manoa's Cancer Center, stated that the findings underscore the importance of diet quality in plant-based eating patterns. The research suggests potential benefits for older adults adopting such diets to mitigate dementia risk. Public health implications include guidance on selecting nutrient-dense plant foods to support cognitive health.