Mediterranean staple may lower your risk of death from dementia, study finds

A daily spoonful of olive oil could lower your risk of dying from dementia, according to a new study by Harvard scientists.

A daily spoonful of olive oil could lower your risk of dying from dementia, according to a new study by Harvard scientists.

For more than 92,000 adults observed over 28 years, consuming at least 7 grams — a bit over half a tablespoon — of olive oil daily was linked with a 28% lower risk of dementia-related death, compared with those who never or rarely ate olive oil, found the study published Monday in the journal JAMA Network Open.

The study is the peer-reviewed and finalized version of an abstract — early research the authors presented in July 2023 at the American Society for Nutrition’s annual meeting. To the authors’ knowledge, it was also the first to investigate whether the Mediterranean diet staple is linked with risk of death from the disease.

“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,” study coauthor Anne-Julie Tessier, a research associate in nutrition at Harvard University’s T.H. Chan School of Public Health, in a news release for the abstract last year. “Opting for olive oil, a natural product, instead of fats such as margarine and commercial mayonnaise, is a safe choice and may reduce the risk of fatal dementia.”

At the beginning of the study, research participants were age 56 on average. The pool included nearly 60,600 women who had participated in the Nurses’ Health Study from 1990 to 2018, and nearly 32,000 men who had been in the Health Professionals’ Follow-Up Study during the same period. The former study investigated risk factors for major chronic diseases among women in North America, while the latter is looking into the same topics but for men.

The authors of the latest study assessed participants’ diets every four years via a questionnaire and the Alternative Healthy Eating Index, which assigns ratings to foods and nutrients predictive of chronic disease. The higher someone scores on this index, the better.

Replacing 5 grams — around 1.2 teaspoons — of margarine or mayonnaise consumed daily with olive oil was associated with an 8% to 14% lower risk of death from dementia. The results of substituting with other vegetable oils or butter weren’t significant, the authors found.