A Regular Mediterranean Diet May Benefit Brain Health

Consuming a Mediterranean-like diet may have a protective effect against memory loss and dementia, according to a new study.

Consuming a regular Mediterranean-like diet may help protect against memory loss and dementia, according to recent research.1 

Mediterranean diets typically consist of more intake of vegetables, legumes, fruit, cereals, fish, and monounsaturated fatty acids, such as olive oil, and lower intake of dairy products, red meat, and saturated fatty acids.

Investigators from the German Center of Neurodegenerative Diseases (DZNE) conducted a nationwide study to assess whether a Mediterranean diet could affect cognitive functions and biomarkers for Alzheimer disease (AD). A total of 512 participants in the study filled out a questionnaire in which they indicated which portions of 148 different foods they had eaten in the past months. Of the study participants, 169 were cognitively healthy and 343 were defined as having a higher risk of developing AD. The study was funded by the Diet-Body-Brain competence cluster at the German Federal Ministry of Education and Research.1,2

Over the course of the study, the investigators examined brain atrophy through brain scans with magnetic resonance imaging scanners to determine brain volume. Participants underwent neuropsychological testing, in which their cognitive abilities were assessed. The investigators also looked at biomarker levels for amyloid proteins and tau proteins in the cerebrospinal fluid (CSF) of 226 participants. Deposits of beta-amyloid proteins and tau proteins are largely responsible for the death of neurons, which contributes to AD. However, the causes of these deposits are still unknown.1,2 

According to the findings, individuals who ate an unhealthy diet had more pathological levels of biomarkers in the CSF than those who regularly ate a Mediterranean diet. Participants who regularly ate fish and vegetables also performed better in the memory tests than those who did not adhere to a Mediterranean diet.1,2 

“There was also a significant positive correlaton between a closer adherence to a Mediterranean-like diet and a higher volume of the hippocampus,” said lead study author Tommaso Ballarini, PhD, postdoctoral fellow.2 “The hippocampus is an area of the brain that is considered the control center of memory. It shrinks early and severely in Alzheimer disease.”

Overall, the investigators reported that higher adherence to a Mediterranean-like diet was associated with large mediotemporal gray matter volume and less amyloid and tau pathology.1

“Our findings corroborate the view of [Mediterranean diet] as a protective factor against memory decline and mediotemporal atrophy,” the investigators concluded.1 “Importantly, they suggest that these associations might be explained by a decrease of amyloidosis and tau-pathology. Longitudinal and dietary intervention studies should further examine this conjecture and its treatment implications.”

References

  1. Ballarini T, van Len DM, Brunner J, Schröder A. Mediterranean diet, Alzheimer disease biomarkers and brain atrophy in old age. Neurology. 2021. Doi: https://doi.org/10.1212/WNL.0000000000012067
  2. DNZE Alzheimer’s study: A Mediterranean might protect against memory loss and dementia. News Release. DNZE; May 5, 2021. Accessed May 7, 2021. https://www.dzne.de/en/news/press-releases/press/dzne-alzheimers-study-a-mediterranean-diet-might-protect-against-memory-loss-and-dementia