Eating a Mediterranean diet could help reduce the risk of dementia and cognitive decline, new research has found.
By following a dietary pattern with a greater intake of vegetables, fruit, cereals, fish and monounsaturated fatty acids – like that from olive oil – the risk of protein build-up and brain atrophy can be reduced.
Such a Mediterranean-led diet also has a low intake of dairy products, red meat and saturated fatty acids.
Previous research has revealed following such a diet can reduce risk of heart disease and support weight loss – but this new research from the DZNE German Centre for Neurodegenerative Diseases has revealed its efficacy in the fight against dementia.
“There was also a significant positive correlation between a closer adherence to a Mediterranean-like diet and a higher volume of the hippocampus,” says Tommaso Ballarini, lead author of the study.
“The hippocampus is an area of the brain that is considered the control centre of memory. It shrinks early and severely in Alzheimer’s disease.
”It is possible that the Mediterranean diet protects the brain from protein deposits and brain atrophy that can cause memory loss and dementia. Our study hints at this.”
In the study, a total of 512 people with an average age of around 70 were analysed – 169 of them were cognitively healthy, while 343 were identified as having a higher risk of developing Alzheimer’s disease.
“People in the second half of life have constant eating habits. We analysed whether the study participants regularly eat a Mediterranean diet – and whether this might have an impact on brain health,” says Professor Michael Wagner, who led the research group.
The participants first filled out a questionnaire in which they indicated which portions of 148 different foods they had eaten in the past months.
Those who frequently ate healthy foods typical of the Mediterranean diet, such as fish, vegetables and fruit, and only occasionally consumed foods such as red meat, scored highly on a scale.
The scientists then investigated brain atrophy through performing brain scans with magnetic resonance imaging (MRI) scanners to determine brain volume.
In addition, all subjects underwent various neuropsychological tests in which cognitive abilities such as memory functions were examined.
The research team also looked at biomarker levels (measured values) for amyloid beta proteins and tau proteins in the so-called cerebrospinal fluid (CSF) of 226 subjects.
The researchers, led by Prof Wagner, found that those who ate an unhealthy diet had more pathological levels of these biomarkers in the cerebrospinal fluid than those who regularly ate a Mediterranean-like diet.
In the memory tests, the participants who did not adhere to the Mediterranean diet also performed worse than those who regularly ate fish and vegetables.
“But the biological mechanism underlying this will have to be clarified in future studies,” adds Ballarini.
As a next step, the research team now plan to re-examine the same study participants in four to five years to explore how their nutrition – Mediterranean-like or unhealthy – affects brain ageing over time.
