mediterranean diet
The Mediterranean may slow down brain shrinking as we age.Westend61/Getty Images

Adopting the 'Mediterranean diet' could slow down brain shrinking in people as they age, scientists have found out. The diet appears to have a prolonged protective effect on the brain, keeping it healthy for longer.

The Mediterranean diet is based on the healthy eating traditions of countries bordering the Mediterranean, such as France, Italy, Spain and Greece. Although regional culinary differences can be observed, the diet typically features vegetables, fruits, nuts, olive oil, cereals and fish.

It has already been shown to confer a range of health benefits and to prolong people's lifespan. It is also believed to have a positive impact on older people's mental health.

In a new research published in the journal Neurology, scientists describe how the diet could also benefit the brain of older adults.

Ageing has been associated with changes to the brain's size and to cognition. The brain's volume shrinks and molecular and morphological changes occur. The study investigates whether the Mediterranean diet could mitigate these effects.

Brain volume changes but not grey matter

The study is based on data collected from 967 Scottish people aged 70 on average and not diagnosed with dementia. The scientists gathered and analysed information on their eating habits. At an average age of 73, 562 of these participants went through an MRI scan to observe their brain volume and morphology. Three years later, 401 of them went through a second scan to look at the evolution. The aspect of people's brain was compared to how closely their diet matched the Mediterranean diet.

After controlling for other factors such as age, education and having diabetes or high blood pressure, the researchers found out that among these participants, those who didn't follow the Mediterranean diet closely were more likely to have a higher loss of total brain volume over three years, between the two scans. This left them more at risk of developing cognitive problems.

mediterranean diet
Olive oil and vegetables are important components of the Mediterranean dietCarolin Voelker/Getty Images

Study author Michelle Luciano of the University of Edinburgh said: "As we age, the brain shrinks and we lose brain cells which can affect learning and memory. This study adds to the body of evidence that suggests the Mediterranean diet has a positive impact on brain health."

Diet differences explained up to 0.5% of variations in brain shrinking – not a massive effect, but significant enough for the Mediterranean diet to be considered as beneficial for the brain's health. However, no link was found between grey matter volume or cortical thickness and the Mediterranean diet.

More studies are needed to confirm the association between brain health and this way of eating, but the findings already indicated that the diet offers sustained brain protection overtime. "In our study, eating habits were measured a few years before brain volume was, which suggests that the diet may be able to provide long-term protection to the brain," said Luciano.