A study featured in The New England Journal of Medicine explored the potential link between diet and the risk of dementia in older adults. While previous research indicated that diet might influence dementia risk, it remained uncertain whether dietary changes could directly enhance cognitive function. The study involved 600 overweight older adults, averaging 70 years of age, who had a family history of dementia.

These participants were split into two groups: one following the MIND diet, a blend of the Mediterranean and DASH diets, and the other practising portion control on its own. Over the course of 3 years, both groups received personalised weekly guidance from dieticians for the first 6 months, followed by biweekly sessions. Their target was to lose 3% to 5% of their initial weight. The MIND group received "brain-healthy" foods weekly, such as olive oil, blueberries, and mixed nuts, while the control group got gift cards.

After 3 years, both groups experienced improved cognitive scores across various aspects compared to their starting points. However, there was no notable difference in cognitive scores between the MIND diet group and the control group. Interestingly, both groups lost around 5 kilogrammes on average, and brain scans of a subset of participants showed similar results for both groups.

Adherence to the MIND diet was confirmed through surveys and biomarker measurements. The noteworthy aspect is that both groups demonstrated cognitive improvements. This suggests that cognitive benefits might be linked to dietary changes and weight loss, or possibly other unrelated behaviours that participants engaged in. Overall, the study sheds light on the complexities of diet, cognitive health, and weight loss among older adults with a familial risk of dementia.