In a recent study posted to The Lancets SSRN* preprint server, researchers investigated the longitudinal relationships between adherence to the Mediterranean-dietary approaches to stop hypertension (DASH) Intervention for Neurodegenerative Delay (MIND) dietary plan and the markers of brain structural alterations among the United Kingdom Biobank (UKBB) study participants.
Study: Mediterranean-DASH Intervention for Neurodegenerative Delay Diet in Relations to Brain Structural Markers and Their Changes. Image Credit: luigigiordano/Shutterstock.com
*Important notice: SSRN publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be regarded as conclusive, guide clinical practice/health-related behavior, or treated as established information.
Background
Aging has increased the prevalence of age-associated neurological disorders, including dementia and Parkinson's disease (PD).
Because decreased brain health can lead to various negative consequences, including dementia and functional decline, discovering effective dietary techniques for safeguarding long-term brain health is critical in an aging world.
The MIND dietary plan, which emphasizes natural plant-origin foods while limiting high-saturated-fat and animal-origin food intake, is linked to a decreased incidence of all-cause dementia, Parkinson's disease, and slower cognitive decline.
However, research linking the MIND dietary plan to alterations in brain anatomical indicators is limited and inconsistent. Furthermore, past research has concentrated on a small number of indicators evaluated only once among a limited number of participants.
About the study
In the present study, researchers investigated brain structural and volumetric alterations among individuals adhering to the MIND dietary plan.
The team included 26,466 individuals from the UKBB study who completed online questionnaires for their 1.0-day dietary recall assessments between 2009 and 2012.
Magnetic resonance imaging (MRI) was performed between 2014 and 2020 to assess alterations in structural markers of the brain. The team evaluated the relationship between the scores for the MIND dietary plan and Z-scores for 17 brain structural markers.
The link between MIND scores and longitudinal alterations in brain structure was evaluated in a subset of 2,963 individuals who underwent repeated MR imaging between 2018 and 2022 [a two-year interval (median) between the assessments]. The participants did not have a history of stroke or dementia.
The MIND scores were determined according to the consumption of 10 healthy food groups (leafy greens, other vegetables, nuts, olive oil, berries, beans, whole grains, non-fried poultry, wine, and non-fried fish) and five unhealthy food groups (cheese, margarine, butter, red meat, sweets and pastries, and fast or fried foods).
The primary study outcomes were the volumes of the total brain, grey and white matter, and the volumes of the subcortical regions.
Questionnaires filled out at study initiation were used to obtain data on covariates such as age, education, sex, body mass index, physical activity, Townsend deprivation index, smoking status, depression, hypertension, cardiovascular diseases, and diabetes.
Results
The mean participant age was 55 years; 54% were female; and a 6.0 median MIND score was obtained at baseline. Individuals with higher MIND diet scores were more educated, older, physically active, and less likely to smoke in current times.
Greater MIND dietary adherence was related to larger sizes and higher volumes of grey matter and certain regions of the brain, such as the putamen, thalamus, pallidum, accumbens, and hippocampus, and -0.03 lower Z-scores for hyperintensities in the white matter. Major contributors to the dietary scores were higher intakes of olive oil and whole grains and lower intakes of fast or fried foods.
The linear mixed modeling results indicated non-significant associations between the MIND dietary scores and structural changes in the brain over two years (median). Higher whole grain intakes were related to the higher total brain, grey matter, and subcortical regional volumes (except the amygdala) and lower Z-scores for hyperintensities in the brain's white matter.
Higher intakes of fried or fast foods were related to lower putamen, thalamus, hippocampus, and pallidum volumes. The stratified analysis findings indicated non-significant relationships between the MIND dietary scores and participant age, but the associations with subcortical volumes showed sex-based differences.
Among men, higher MIND scores were linked to higher total brain, grey matter, and white matter volumes, but the associations were reversed for women. In addition, the associations were significant for men but not for women.
The sensitivity analyses, excluding comorbidities and restricting analyses to individuals who completed ≥2.0 diet assessments, yielded similar results.
Conclusion
Overall, the study findings showed positive associations between the scores for the MIND dietary plan and hyperintensities in the white matter and subcortical brain area volumes for middle-aged adults and the elderly.
However, further research is required to validate the connections with longitudinal structural alterations in the brain and to elucidate the underlying processes relating food consumption to brain structural and volumetric health.
*Important notice: SSRN publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be regarded as conclusive, guide clinical practice/health-related behavior, or treated as established information.
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