A new collaborative study by the University of Edinburgh shows that older people who followed a Mediterranean diet retained more brain volume over a three-year period than those who did not follow the diet as closely. The Mediterranean diet includes large amounts of fruits, vegetables, olive oil, beans and cereal grains such as wheat and rice, moderate amounts of fish, dairy and wine, and limited red meat and poultry.
This study adds to the existing body of evidence suggesting that Mediterranean diet is one of the most beneficial types of diets and has a positive impact on brain health. The main author of the study Dr Michelle Luciano said “As we age, the brain shrinks and we lose brain cells which can affect learning and memory.”
Michelle and her co-authors gathered information on the eating habits of 967 Scottish people aged 70 who did not have dementia and nearly half of the participants had a brain scan performed at ages 73 and 76 to measure volume of the brain and cortical thickness. The participants varied in how closely their dietary habits followed the Mediterranean diet principles. The researchers found that people who did not follow as closely to the Mediterranean diet were more likely to have a higher loss of total brain volume over the three years than people who followed the diet more closely. The difference in diet explained 0.5 percent of the variation in total brain volume, an effect that was half the size of that due to normal aging.
Contrary to earlier studies, eating more fish and less meat was not related to changes in the brain, suggesting that other components of the Mediterranean diet or, possibly, all of its components in combination are responsible for the association. Michelle also noted that earlier studies looked at brain measurements at one point in time, whereas the current study followed people over time. “In our study, eating habits were measured before brain volume was, which suggests that the diet may be able to provide long-term protection to the brain.”
It is still not entirely clear what this finding that diet has a small effect on changes in brain size could mean in terms of the development of dementia – researchers now need to investigate how the dietary risk or protective factors impact on possibly delaying or preventing the onset of dementia.
Full text of this paper can be found with open access here.