Consuming olive oil could reduce risk of dying from dementia by a third, study suggests

Olive oil has long been held up as an example of a "super food" that can help you to live longer when consumed as part of a healthy diet. Now a new study suggests that olive oil could help to reduce the risk of dying from dementia.

The study, conducted by researchers at Harvard University in the United States, comes at a time when many countries are facing rising rates of Alzheimer’s disease and other forms of dementia, amid ageing populations.

According to the researchers, using olive oil instead of fats such as margarine and commercial mayonnaise could reduce the risk of dying from dementia.

Dementia includes a range of conditions that affect memory and other mental abilities enough to interfere with daily life. The conditions are caused by physical changes in the brain, with Alzheimer's disease being the most common type.

In the first study to investigate the relationship between diet and dementia-related death, scientists analysed the dietary questionnaires and death records of more than 90,000 US citizens over three decades. Of these, 4,749 were recorded as dying from dementia.

They found that those who consumed more than half a tablespoon of olive oil each day had a 28 per cent lower risk of dying from dementia compared with those who never or rarely ate olive oil.

The study showed how replacing a single teaspoon of margarine or mayonnaise with olive oil each day was also associated with a lower risk of dying from dementia of between 8-14 per cent.

“Our study reinforces dietary guidelines recommending vegetable oils such as olive oil and suggests that these recommendations not only support heart health but potentially brain health, as well,” said Anne-Julie Tessier, a postdoctoral fellow at the Harvard TH Chan School of