A diet rich in vegetables, fruit, fish, nuts, whole grains, lean meat and olive oil has long been associated with better brain health.
Its ability to reduce your risk of dementias like Alzheimer’s has also been described, but the precise mechanism has remained a mystery.
Now, researchers from Edith Cowan University, with colleagues from the Florey, CSIRO and a number of other institutions, have examined dietary information and amyloid build-up in 77 Australians to tease apart what’s going on.
The study participants were all unaffected by Alzheimer’s disease during the three-year study, but did have increasing amyloid levels. This indicated that while they were currently healthy, they were on the pathway to developing the disease in the future.
They were then divided into three groups who had a low, medium or high consumption of Mediterranean diet ingredients.
Those who stuck to the diet and consumed the healthiest foods – especially fresh fruit – showed a slower rate of amyloid build-up in their brains over three years by up to 60% compared to someone who consumed unhealthier foods.
Importantly, the team also examined the participants’ genetic status, to rule out any effect of modifying genes that can speed up or slow down amyloid accumulation. Genetic status did not affect the results, showing that diet can in fact influence a key driver of Alzheimer’s disease.
Dr Yen Ying Lim, head of the Florey’s Healthy Brain Project, said, “This is a really important paper for the field to digest, if you’ll pardon the pun. For 20 years we’ve thought of amyloid buildup as a pathological process that is inevitable in certain individuals. More and more data is emerging however, showing that lifestyle factors, especially increasing physical activity and a diet rich in olive oil, fresh fruit and veg, whole grains and lean meats and fish can modify the disease process. The earlier you start, the more pronounced the effects. Also, there’s now no doubt that there’s a significant overlap between Alzheimer’s and other dementias like vascular dementia. These factors will likely confer some protective effect against all dementias.”