A new analysis suggests the MIND diet may offer the greatest cognitive benefits for older adults with early biological signs of Alzheimer's disease.
Researchers examined data from a three-year clinical trial involving more than 600 adults ages 65 to 84.
The findings add nuance to earlier results, but researchers say more studies are needed before drawing firm conclusions.
As people look for ways to support healthy aging, the foods they eat have become an area of growing interest. While no single diet can prevent dementia, researchers have been studying whether certain eating patterns may help protect memory and thinking skills over time.
A new analysis from researchers at Rush University Medical Center takes a closer look at the MIND diet, an eating plan that combines elements of the Mediterranean and DASH diets while emphasizing foods such as leafy green vegetables, berries, whole grains, nuts, beans, olive oil, fish, and poultry. The researchers wanted to know whether the diet's effects differed depending on a person's underlying Alzheimer's disease biology.
“In our analysis of data from the MIND trial, we found that the association between the dietary intervention and cognition varied by how much beta-amyloid and phosphorylated tau individuals had in the blood at the start of the study, raising the possibility that the MIND diet may be more beneficial for individuals with higher levels of these blood biomarkers,” researcher Klodian Dhana, MD, PhD, said in a news release.
How the study was conducted
The researchers analyzed data from the MIND clinical trial, a randomized study that enrolled 604 community-dwelling adults between the ages of 65 and 84 who did not have cognitive impairment but were considered at higher risk because they had a family history of dementia, were overweight or obese, and had relatively poor diets at the start of the study.
Participants followed either the MIND diet or a control diet for three years, and both groups received the same amount of dietary counseling and support for modest weight loss.
Unlike the original 2023 report, which looked at the overall trial population, this new analysis grouped participants based on blood biomarkers associated with Alzheimer's disease. Researchers then compared changes in overall cognitive performance across those different biomarker groups.
What the results could mean for consumers
The analysis found that participants with low levels of phosphorylated tau-181 (p-tau181), a biomarker linked to early Alzheimer's disease, appeared to receive the greatest cognitive benefit from following the MIND diet.
Among people with higher levels of the biomarker, the diet did not appear to provide the same advantage. Researchers say this suggests the timing of dietary changes may matter, with interventions potentially having a greater effect earlier in the disease process.
The findings also help explain why the original trial showed only a modest overall difference between the MIND and control diets. In that study, both groups improved cognitively and lost about 11 pounds over three years, making it difficult to determine how much of the benefit came from the diet itself versus weight loss or other healthy lifestyle changes.
For consumers, the study reinforces that healthy eating remains an important part of overall wellness, but it is not a guaranteed way to prevent cognitive decline. Researchers say future studies will be needed to determine which people are most likely to benefit from dietary interventions and when those changes may have the greatest impact.