Choosing olive oil over margarine and mayonnaise may reduce dementia mortality risk

Key takeaways:

• Consuming more than half a tablespoon of olive oil per day was linked to a 28% lower risk for mortality due to dementia.
• Researchers said the relationship was independent of diet quality.

BOSTON — Replacing mayonnaise and margarine with olive oil may reduce the risk for mortality from dementia among adults in the United States, according to study results presented at NUTRITION 2023.

Previous research indicates that olive oil may offer benefits when it comes to mortality, cardiovascular health and, possibly, cognition, Anne-Julie Tessier, RD, PhD, a postdoctoral researcher at the Harvard T.H. Chan School of Public Health, and colleagues reported. But whether there is a link between olive oil consumption and dementia mortality has not yet been studied.

So, Tessier and colleagues conducted a study including 60,582 women and 31,801 men to evaluate the connections between olive oil intake and subsequent risk for dementia-related mortality, which they ascertained from death records. The researchers measured diet every 4 years with a semiquantitative food frequency questionnaire and diet quality with the Alternative Healthy Eating Index (score 0-110).

In the 28 years of follow-up, 4,749 participants died from dementia.

Tessier and colleagues reported that consuming more than half a tablespoon of olive oil per day translated to a 28% lower risk for fatal dementia compared with rarely or never consuming olive oil. Additionally, replacing 5 g of margarine and mayonnaise per day with an equivalent amount of olive oil was linked to an 8% to 12% lower risk for fatal dementia. However, substitutions with butter or other vegetable oils did not yield a significant association, according to the researchers.

“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,” Tessier said in a press release. “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.”

Tessier also said in the release that the relationship they observed between dementia mortality risk and olive oil “was independent of overall diet quality,” which could indicate “olive oil has properties that are uniquely beneficial for brain health.”

“Some antioxidant compounds in olive oil can cross the blood-brain barrier, potentially having a direct effect on the brain,” Tessier said in the release. “It is also possible that olive oil has an indirect effect on brain health by benefiting cardiovascular health.”

Reference:

• Tessier AJ, et al. Olive oil intake and fatal dementia risk in two large prospective U.S. cohort studies. Presented at: NUTRITION; July 22-25, 2023; Boston.