By Tessa Koumoundouros.

Mounting evidence suggests adding just a spoonful of olive oil to your diet each day can have powerful health benefits. A new study from the US suggests this includes protection against dementia.

While healthy ‘Mediterranean’ diets in general tend to include a dash of olive oil, the researchers claim the ingredient itself stands out for its beneficial qualities.

“Typically, people who use olive oil for cooking or as a dressing have a better overall diet quality, but interestingly, we found the association to be regardless of this factor,”

Harvard University nutritionist Anne-Julie Tessier told Kaitlin Vogel at Healthline.

Tessier and colleagues combined the results of surveys on nurses and health professionals conducted from the 1970s and 1980s. All were free of heart disease and cancer when the surveys first introduced questions on olive oil consumption in 1990. In the years that followed, 4,751 of the 92,383 selected participants died from dementia-related causes.

The researchers found adults who regularly consumed more than 7 grams of olive oil a day (about half a tablespoon) were 28 percent less likely to die of dementia-related diseases compared to those who never or rarely consumed olive oil.

“Olive oil may exert anti-inflammatory and neuroprotective effects due to its high content of monounsaturated fatty acids and other compounds with antioxidant properties such as vitamin E and polyphenols,”

Tessier and team explain in their paper.

Animal studies suggest specific types of fats, such as monounsaturated fatty acids found in olive oil, can have protective benefits on health, and polyphenols can help prevent the amyloid-plaques associated with Alzheimer’s disease.

“There is… some evidence showing that it is the combination of all these different compounds more than a single element responsible for the positive effects,”

Temple University neuroscientist Domenico Praticò, who was not involved in the study, told Robby Berman at Medical News Today in 2023.

Study participants were primarily White and educated, meaning the results can’t yet be generalized across diverse populations. What’s more, as it was an observational study the researchers can’t directly link the outcomes to olive oil, just yet.

However, previous research has also suggested people who regularly consume olive oil have about a 30 percent lower risk of dying from a neurodegenerative disease.

With rates of dementia continually increasing globally and no cure, preventative measures through diet, physical and mental exercises are the best chance we’ve got of mitigating these diseases, which currently affect more than 55 million people globally.

Olive oil is likely a key component behind the consistently positive health outcomes of a Mediterranean diet. But not everyone has the same access to the full diet, so understanding which parts of it make the biggest health impacts can go a long way towards helping our most vulnerable people improve their health.

This research was published in JAMA Network Open.

> Consumption of Olive Oil and Diet Quality and Risk of Dementia-Related Death

Tessa Koumoundouros is Journalist and editorial assistant at ScienceAlert. She is fascinated by all living things, so it’s no surprise she mainly writes about biology, health, and the environment.

Tessa has contributed behind the scenes at The Conversation and the Climate Council, and her science reporting has been published by Lateral Magazine. She holds a Bachelor of Science with honors, majoring in zoology and genetics, and a Masters in Science Communication. She also worked as an exotics veterinary nurse, before joining the ScienceAlert editorial team in 2018.

She is an accomplished illustrator and designer, and puts her skills to work when curating incredible images for ScienceAlert’s social media, and designing infographics such as the This Week in Science series.

In her spare time, Tessa loves exploring wild places, stalking wildlife with a camera, reading, and drawing.