Mediterranean diet could lower risk of dementia, study suggests

People who eat a diet rich in fruits, vegetables, olive oil and fish could be at lower risk of dementia, a new study has suggested.

Researchers from the German Centre for Neurodegenerative Diseases in Bonn found the so-called Mediterranean diet could protect the brain from disease triggers associated with Alzheimer's, specifically protein deposits and the rapid loss of brain matter.

Alzheimer's disease is the most common form of dementia, affecting between 50 and 75 per cent of people diagnosed with the condition.

In the UK, approximately 850,000 people have dementia and one in six people over the age of 80 are affected by it. Seven out of ten care home residents have dementia or severe memory problems, according to the Alzheimer's Society.

The recent study in Germany, results of which were published in the journal Neurology, involved 512 subjects with an average age of 70 years. The participants were asked to fill out a questionnaire about the foods they ate regularly. Those who ate a lot of fish, vegetables and fruit, and only occasionally consumed foods considered less healthy, such as red meat, were given high scores on a scale used by the researchers.

Participants then underwent MRI brain scans and took part in tests examining cognitive functions such as memory. The study also looked for levels of amyloid beta proteins and tau proteins - well-known hallmarks of Alzheimer's - in the cerebrospinal fluid.

The results showed that people with the most unhealthy eating habits had more pathological levels of these biomarkers than those who regularly ate a Mediterranean diet.

Furthermore, people who regularly consumed a lot of fish, fruit and vegetables performed better in memory tests.

Expanding on the findings, Tommaso Ballarini, lead author of the study, said: "There was also a significant positive correlation between a closer adherence to a Mediterranean-like diet and a higher volume of the hippocampus. 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."

The researchers plan to re-examine the same study participants in four to five years, to gain further insights into how nutrition can affect brain ageing and health over time.