Extra-virgin olive oil found to be beneficial for mice with features of Alzheimer’s

21 June 2017

Annals of Clinical and Translational Neurology: Extra-virgin olive oil ameliorates cognition and neuropathology of the 3xTg mice: role of autophagy

A new study from researchers in the US and Italy has looked at the effects of a diet enriched in extra-virgin olive oil on mice with features of Alzheimer’s, finding that it reduced levels of toxic hallmark Alzheimer’s proteins and improved various aspects of nerve cell health. The findings are published today (21 June) in Annals of Clinical and Translational Neurology.

The researchers used mice with features of Alzheimer’s disease, and these mice normally show the build-up of toxic proteins associated with Alzheimer’s disease, called amyloid and tau. The team fed these mice either a normal diet, or one enriched with extra-virgin olive oil (EVOO) from when the mice were mature adults at 6 months old.

They tested the memory and thinking skills of the mice at ages 6, 9 and 12 months, finding that the group fed the EVOO-enriched diet performed better than mice fed a normal diet. When the researchers looked at the brains of the 12-month-old mice (following 6 months of treatment), they found that those fed the EVOO-enriched diet had lower levels of amyloid and tau, lower levels of inflammation and stronger connections between nerve cells. A cellular waste disposal system called autophagy was also found to be boosted in the mice fed the EVOO-enriched diet. The researchers suggest that these processes may underpin some of the beneficial effects of the Mediterranean diet and its link with dementia risk.

Dr Rosa Sancho, Head of Research at Alzheimer’s Research UK, said:

“A Mediterranean-style diet that is low in meat and dairy but rich in fresh fruit and vegetables, cereals, beans, nuts and ‘healthy’ fats like olive oil, has been linked to a range of health benefits, including a lower risk of dementia. In this new study, the researchers homed in on one particular aspect of the diet, extra virgin olive oil, finding that it had positive effects in mice with features of Alzheimer’s. By probing the mechanisms thought to underpin Alzheimer’s disease, the team have indicated ways in which extra-virgin olive oil could be having positive effects on the brains of the mice. What is not clear from the study is how much extra-virgin olive oil the mice were being given to bring about this effect, and we do not know whether the oil could have similar effects in people.

“Further studies will need to explore the reported effects of extra-virgin olive oil before we could say that it holds health benefits beyond those of any other component of a healthy diet. While there is currently no certain way to prevent dementia, evidence suggests the risk can be lowered with a healthy lifestyle including a balanced diet, regular exercise, not smoking, and keeping weight and blood pressure in check.”