The MIND Diet May Lower Dementia Risk Among Middle-Aged, Older Adults

The Mediterranean Dietary Approaches to Stop Hypertension (DASH) Intervention for Neurodegenerative Delay (MIND) diet is associated with a decreased risk of developing dementia in older adults, according to an analysis of observational studies published in JAMA Psychiatry.

Amongst potential risk factors for dementia, dietary factors, including food groups, specific nutrients, and dietary patterns have been the subject of much interest. Previous research has found that the MIND diet, — a combination of the Mediterranean and DASH diets — which focuses on plant-based foods, limited intake of animal-based foods and those high in saturated fat, and promotes berries and leafy green vegetables, has shown promising results in lowering the risk for Alzheimer disease (AD) and slowing cognitive decline.

For the study, researchers aimed to assess the association of the MIND diet with the risk for dementia by analyzing 3 prospective studies and a meta-analysis.

The researchers conducted a cohort study from 3 prospective studies: the UK’s Whitehall II cohort, and the US’s Health and Retirement Study and the Framingham Heart Study Offspring cohorts, in which the MIND diet was utilized. All studies assessed diet prior to the diagnosis of dementia. Individuals aged 45 years and older who completed 1 or more valid food frequency questionnaires (FFQs) were included in the study. Participants who developed dementia in the first 2 years of follow-up or had dementia at baseline were excluded from the study.

In each study, requisite MIND diet scores were obtained, ranging from 0-15, with a higher score signifying a higher adherence to the diet. Primary outcome of interest was all-cause dementia.

Additionally, a meta-analysis was conducted on cohort studies that assessed the association of the MIND diet and incident dementia.

A total of 18,136 men and women were evaluated in the 3 studies with a total of 775 participants who developed incident all-cause dementia. These were the mean baseline MIND diet scores across all 3 cohorts:

• Whitehall II: 8.3
• Health and Retire Study:7.1
• Framingham Offspring: 8.1

Median follow-ups were 12.9 years, 5.0 years, and 10.7 years, respectively.

Multivariable adjusted models found pooled hazard ratios (HRs) to be 0.81 (95% CI, 0.67-0.98) for the highest vs lowest tertiles of MIND score.

In these cohorts, the HRs for every 3-point increment were:

• Whitehall II: 0.97 (95% CI, 0.72-1.30; P for trend = .83))
• Health and Retire Study: 0.82 (95% CI, 0.68-0.99; P for trend = .04)
• Framingham Offspring: 0.76 (95% CI, 0.57- 1.00; P for trend = .04)

Lower consumptions of red meat and higher consumption of vegetables, berries, nuts, and beans are all potential contributors these findings.

Subgroup analysis did not find any association between smokers and dementia (HR, 1.10; 95% CI, 0.68-1.75). No significant associations were found when evaluating by sex, age, and body mass index (BMI).

Sensitivity analysis found similar results. Using alternate cutoffs for MIND scores, HR for a score of 7.0-8.9 was 0.95 (95% CI, 0.80-1.13) and 0.75 (95% CI, 0.60-0.93) for a score of 9.0-15.0, compared with MIND score less than 7.0.

In reference to the meta-analysis, 11 cohort studies were included and found 5,279 incident dementia cases from 224,029 participants. Comparing highest vs lowest tertile of MIND diet score, HR was found to be 0.83 (95% CI, 0.76-0.90; P for trend = .01) for every 3-point increment.

Limitations of the study included the inability to differentiate subtypes of dementia due to inconsistent definitions across cohorts.

“In this analysis of 3 cohort studies and a meta-analysis, findings suggest that adherence to the MIND diet was prospectively associated with lower dementia risk, although moderate heterogeneity was observed across studies,” the researchers wrote. They concluded, “Future studies are needed to evaluate and refine the MIND diet in different populations and to identify the optimal intervention time window for dementia prevention.”