Olive Oil and Longevity: Why Harvard is Interested

A cornerstone of the Mediterranean diet, olive oil is gaining increasing attention from researchers for its potential impact on lifespan and health. At the Harvard T.H. Chan School of Public Health, ongoing research aims to quantify the relationship between olive oil consumption and longevity, focusing on a measurable daily intake and its accessibility for individuals.

Olive Oil’s Impact on Dementia and Mortality

Two key studies are driving this research. A study published in JAMA Network Open on May 6, 2024, explored the link between olive oil consumption and dementia. Earlier, in 2022, research published in the Journal of the American College of Cardiology investigated the association with all-cause mortality.

The Optimal Daily Intake: Effects on Dementia

The JAMA Network Open study followed 92,383 adults for nearly 28 years, utilizing dietary questionnaires and death records. Researchers found that consuming more than half a tablespoon (approximately 7 grams) of olive oil daily was statistically associated with a 28% reduction in the risk of death from dementia. Substituting just one teaspoon of margarine or mayonnaise with the equivalent amount of olive oil was linked to an 8-14% reduction in risk, regardless of overall dietary patterns.

“Our study reinforces dietary guidelines recommending vegetable oils such as olive oil and suggests that these recommendations not only promote heart health but also potentially brain health. Opting for olive oil, a natural product, instead of fats such as margarine and commercial mayonnaise is a safe choice and can reduce the risk of fatal dementia,” Anne-Julie Tessier, researcher at the Harvard T.H. Chan School of Public Health

The authors emphasize that these results are observational and require confirmation through randomized controlled trials.

Increased Longevity: Findings from the Journal of the American College of Cardiology

The 2022 study in the Journal of the American College of Cardiology analyzed data from over 90,000 participants followed for almost 28 years. The results indicated that consuming more than 7 grams of olive oil per day – slightly more than half a tablespoon – was associated with a 19% lower risk of all-cause mortality compared to those who rarely or never consumed it.

The analysis also highlighted that the benefits stemmed primarily from substitution rather than simply adding olive oil to the diet. Replacing 10 grams of margarine, butter, or mayonnaise with olive oil resulted in an 8-34% reduction in mortality risk. This is attributed to olive oil’s rich content of oleic acid and polyphenols, contrasting with the higher saturated fatty acid content of other fats.

Integrating Olive Oil into Your Daily Diet

Studies suggest positive effects from a modest amount – a little more than half a tablespoon daily. This can be easily incorporated into meals by:

• Using it as a raw seasoning on salads or vegetables.
• Adding it at the end of cooking to fish or vegetables.
• Substituting butter at the table or mayonnaise in sauces.

To preserve its quality, it’s advisable to choose extra virgin olive oil stored in a dark bottle or container, away from light. While gentle cooking is possible, the aromas and polyphenols are best preserved when consumed raw.

Researchers acknowledge the need for further investigation to determine the optimal quantity and fully understand the underlying biological mechanisms. However, the current evidence suggests that replacing certain animal or processed fats with olive oil may contribute to improved long-term health.