Choosing nuts, fish, veggies and olive oil over a low-fat diet could help stave off mental decline, according to new research.
The authors from the University of Navarra in Spain base their findings on 522 men and women aged between 55 and 80 without cardiovascular disease but at high vascular risk because of underlying disease or conditions. (These included either type 2 diabetes or three of the following: high blood pressure; an unfavorable blood fat profile; overweight; a family history of early cardiovascular disease; and being a smoker.)
A Mediterranean diet is characterized by the use of virgin olive oil as the main culinary fat; high consumption of fruits, nuts, vegetables and pulses; moderate to high consumption of fish and seafood; low consumption of dairy products and red meat; and moderate intake of red wine.
Participants were randomly assigned to a Mediterranean diet with added olive oil or mixed nuts or a control group receiving advice to follow the low-fat diet typically recommended to prevent heart attack and stroke.
After an average of 6.5 years, they were tested for signs of cognitive decline using a Mini Mental State Exam and a clock drawing test, which assess higher brain functions, including orientation, memory, language, visuospatial and visuoconstrution abilities and executive functions such as working memory, attention span, and abstract thinking.
The average scores on both tests were significantly higher for those following either of the Mediterranean diets compared with those on the low fat option.
These findings held true irrespective of other influential factors, including age, family history of cognitive impairment or dementia, the presence of ApoE protein—associated with Alzheimer’s disease—educational attainment, exercise levels, vascular risk factors; energy intake and depression.
The study was published online in the Journal of Neurology Neurosurgery and Psychiatry.