A Mediterranean-type diet has previously been looked at to view its effects on the aging brain. It was found that those who did not adhere to such a diet showed visible signs of reduced brain volume over a 3-year time period.
Understanding the process of healthy aging and the factors associated with it is very important, specifically when those factors are improvable and documentable, such as diet. Mediterranean-type diets have been studied and linked to a decrease in inflammation and risks for Parkinson’s, Alzheimer’s, cardiovascular disease, and cancer. Furthermore, it has been shown to increase cognitive function. Therefore, the study “Mediterranean-type diet and brain structural change from 73-76 years in a Scottish cohort” was done to test the effects of such a diet on brain volume and cortical thickness. The diet included an increased intake of fruits, vegetables and legumes, cereals, and olive oil for fat. It also included a moderate intake of fish and low intake of dairy, wine, red meat, and poultry.
From 2004-2014, 1091 patients born in 1936 from Edinburgh, Scotland were recruited, specifically those who had completed a mental ability test at the age of 11. Subjects were put on a strict Mediterranean-type diet for three years (2004-2007), and were scored based on the Scottish Collaborative Group 168-item Food Frequency Questionnaire, where foods that were supposed to be increased in their diets were given a score of 1 (such as fruit) and foods that were supposed to be decreased were given a score of 0 (such as red meat). During these first three years, medical history and demographics were also taken into account. Cognitive tests were then done from 2007-2010, when all subjects were about 73 years old, and from 2010-2014, when all subjects were about 76 years old. These tests were done using an MRI scan, which looked at cognitive function and brain structure and volume.
It was found that subjects who had a lower adherence to the Mediterranean-type diet had shown a reduction in brain volume, however, there was no significant change in cortical thickness. Furthermore, it was found that the consumption of fish and meat specifically did not replicate previous studies, as they did not have a significant change on brain volume. This could have been due to differences in the type of fish that was consumed (oily vs white). This may also be due to the protective nature of the Mediterranean-type diet, providing a total protection against the atrophy (wasting) of the brain, specifically for those with greater adherence to the diet. Furthermore, those subjects that had a high fish and low meat intake, still, did not have a significant decrease in the volume of their brain, which could, again, be the case that other components of the diet are more directly involved in the effects on total brain volume. The identification of these specific components has yet to be determined.
Written By: Unaisa Bhayat, BMedSc