Following a Mediterranean diet could reduce brain shrinkage in older age, PPLS research suggests
A study from PPLS has found that a group of healthy older adults in Scotland who ate a diet rich in fresh fruit, vegetables and olive oil had healthier brains than a similar group with different eating habits. In particular, they suffered less brain shrinkage than those who regularly ate meat and dairy products. Researchers based in Psychology, led by Dr Michelle Luciano, carried out brain scans on 401 members of the Lothian Birth Cohort, who also provided information on what they ate.
The Mediterranean diet is rich in vegetables, fruits, olive oil, beans and cereal grains. It includes moderate amounts of fish, dairy products and wine, but limits consumption of red meat and poultry. Researchers found that those whose food intake matched the Mediterranean diet most closely, retained significantly greater brain volume after three years, compared with those who followed a different diet.
Lead researcher Dr Michelle Luciano 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."
The Lothian Birth Cohort is a unique resource for researchers in PPLS, as it includes hundreds of people, now in their 70s and 80s, whose IQ was measured aged 11 – meaning researchers can cross-check people’s behaviours and brain health in older age, against what would be predicted from their early IQ scores. The researchers can also adjust for other potential influences on brain health, such as age, education, diabetes or high blood pressure.
Adjusting for these factors did not affect the major finding: that diet accounted for about half of the variation in brain volume loss due to normal ageing.
The research differs from previous studies, because it followed the participants over a period of 6 years. Participants provided the initial data on food intake when they were aged 70, and then took part in two rounds of brain scanning, when they were aged 73 and again aged 76. This allowed researchers to measure changes over time. Previous studies have carried out measurements in a single "snapshot”, all at once.
Larger studies are needed to confirm these results and to answer further questions about the potential of the diet to offer protection against dementia and loss of cognitive ability. The study is published in the 4 January online issue of Neurology, the medical journal of the American Academy of Neurology.
Luciano, M., Corley, J., Cox, S. R., Hernández, M. C. V., Craig, L. C., Dickie, D. A., ... & Deary, I. J. (2017). Mediterranean-type diet and brain structural change from 73 to 76 years in a Scottish cohort. Neurology, 10-1212.