Can Olive Oil Reduce Dementia-Related Deaths?

With apologies to Mary Poppins, it looks like a teaspoon of olive oil might be more helpful than sugar.

In a new study – covering almost 30 years – Harvard University researchers reveal a promising connection between olive oil consumption and a reduced threat of dementia-related mortality.

The results, culled from an exhaustive cohort study including more than 90,000 participants, uncovered intriguing evidence supporting the potential cognitive benefits of integrating the liquid fat into one’s diet.

Ambitious Scope

The paper, appearing in JAMA Network Open, followed the dietary habits of 92,383 adults over 28 years. The participants, none of whom had received either a cardiovascular disease or cancer diagnosis, regularly filled out food frequency questionnaires. The researchers hoped to assess their olive oil intake while establishing the quality of the diets overall.

The researchers found that individuals who consumed more than seven grams of per day (g/d) of olive oil enjoyed a notable 28% lower risk of dementia-related death compared to those who rarely or never consumed it. This connection persisted even after the researchers adjusted for variables such as diet quality, lifestyle choices, and genetic influences like the APOE ε4 allele, which scientists have established influences dementia risk.

“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,” Anne-Julie Tessier, PhD, a postdoctoral fellow at the Harvard T.H. Chan School of Public Health and the lead author of the study, said. “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.”

Other Benefits of Olive Oil

As Tessier suggested, the paper highlighted the potential benefits of substituting the Mediterranean diet staple for other fats in one’s diet. The research team found that replacing 5 g/d of margarine or mayonnaise with olive oil produced a notable 8 percent to 14 percent drop in dementia mortality risk.

Notably, the study authors didn’t see the benefit when participants subbed in butter or other vegetable oils, implying a protective effect unique to olive oil.

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

Putting Results Into Action

The researchers emphasize just how groundbreaking these findings appear to be, suggesting that olive oil consumption could serve as a practical dietary strategy to mitigate the growing burden of dementia-related mortality.

The study’s authors also proposed amending existing dietary recommendations to include olive and other vegetable oils for cognitive health and their established cardiovascular health benefits. They added that this research paves the way for individuals to head off dementia risk with the help of simple dietary adjustments.

Finally, Tessier and her team conceded the observational nature of their research – despite its scope – demands additional investigation. As such, they’ve argued that future research should incorporate randomized controlled trials to expose the underlying mechanisms and confirm their observational associations.

Further Reading

Risk Score for Predicting Mortality in People With Dementia

THC for Neuropsychiatric Symptoms of Dementia

Cognitive Decline and Dementia in a Young Patient