New Link Between Olive Oil and Dementia Discovered: "Already 14% Less Likely if You Replace 5 Grams of Mayonnaise With Oil"

A new study finds olive oil may lower dementia risk: swapping mayonnaise for oil can cut risk by 14%.

If you mostly use butter when cooking in your kitchen, it might be time to switch to olive oil for a healthier brain later in life. Regular olive oil consumption could reduce the risk of dementia-related death by 28%, according to a recent study from the United States. Yannick Vermeiren, a Professor of Nutrition and Brain Health at Wageningen University, sheds light on the connection between olive oil and dementia.

American researchers in Boston discovered that individuals consuming at least 7 grams of olive oil daily — approximately a small tablespoon — were significantly less likely to succumb to dementia-related causes compared to those who seldom or never consumed olive oil. Their findings, published in JAMA Network Open, were based on tracking 92,000 individuals over 28 years through surveys. Olive oil intake was measured from its use in salads, baking, or as a bread additive.

Notably, the olive oil-dementia link persisted regardless of overall dietary habits. Vermeiren emphasizes, "Even if their diet wasn't particularly healthy, the benefits of olive oil remained." While adherents of a Mediterranean diet showed the lowest dementia risk, even small dietary tweaks had substantial impacts. For instance, substituting 5 grams of mayonnaise with olive oil daily reduced dementia risk by 14%.

Our brains, comprised of 60% fat, require fats for optimal function and aging. Vermeiren clarifies, "Brain cells' outer layers consist of a double phospholipid membrane, while their extensions are rich in myelin, a fatty substance lending the brain its white color. Thus, fat intake is crucial for brain health."

The link between olive oil and dementia has been supported by various studies. Vermeiren cites a 2015 Spanish study demonstrating the dementia risk reduction associated with a Mediterranean diet enriched with olive oil. Additionally, the World Health Organization endorsed a Mediterranean diet in 2019 for preserving cognitive abilities among seniors: about 1 liter of olive oil per week per household could firmly reduce the risk of dementia. 

At Wageningen University, ongoing research focuses on how Mediterranean and MIND diets can stave off dementia. A two-year lifestyle intervention involving 1,200 seniors at risk of Alzheimer's aims to explore the impact of healthy fats, including those from olive oil, with results expected next year.