Have long-term brain health on…well, the brain? Then it’s time to get more olive oil onto your plate. A new study found that participants who consumed over seven grams of olive oil every day had a 28 percent lower risk of dying from dementia compared to those who never or rarely ate it, with higher intake as a whole being associated with a lower risk of mortality related to dementia—all regardless of overall diet quality.
The Harvard researchers behind this cohort study, published in JAMA Network Open in 2024, examined existing data from 1990 to 2018 found in the Nurses’ Health Study and the Health Professionals Follow-Up Study, which homed in on over 90,000 participants’ olive oil consumption (with check-ins every four years). Participants were split into four groups according to frequency of olive oil intake, ranging from never or once monthly to over seven grams (just shy of a tablespoon) daily.
What does science say about olive oil?
A staple of many households, olive oil is routinely championed for a slew of powerful health benefits, including but not limited to reducing inflammation and mitigating risk factors for cardiovascular disease, cancer, and diabetes. Additional research has also demonstrated its ability to boost cognitive function and reduce cognitive decline, but the specific link between olive oil consumption and dementia-related mortality was previously unknown.
“This well-designed, methodologically sound, and carefully analyzed prospective study adds to the growing evidence of the benefits of olive oil on brain health,” says Tassos C. Kyriakides, PhD, an assistant professor of biostatistics at the Yale School of Public Health and a certified olive oil sommelier.
Is regular olive oil or extra-virgin olive oil better?
Amal Kaddoumi, PhD, professor in the department of pharmacology and toxicology at Auburn University, says that these results weren’t surprising as they supported findings from a clinical trial, published in the journal Nutrients in 2022, which she led alongside Kyriakides and a team of other researchers. This one investigated the effects of consuming 30 milliliters (about two tablespoons) of either regular olive oil (ROO) or extra virgin olive oil (EVOO) daily in participants with reported mild cognitive impairment.
“After six months of olive oil consumption, our findings showed that both EVOO and ROO improved cognitive function as determined by the improved clinical dementia rating and other behavioral scores,” she shares. However, EVOO and ROO consumption showed different MRI results: EVOO improved the function and integrity of the blood-brain barrier, which is vital for a healthy brain since it protects against exposure to blood-related neurotoxins and helps clear brain waste products, Kaddoumi explains.
Meanwhile, ROO increased brain activity in parts of the brain involved in cognition when participants were given a memory task. “Not only that, but we found that olive oil reduced oxidative stress and inflammation markers,” she continues, “which collectively could explain, at least in part, the positive observed effect in the Harvard cohort study.”
In short, a growing amount of research indicates that both olive oil and EVOO have earned a rightful place in your pantry. “Adding olive oil to our diet could maintain a healthy brain, improve memory function, and reduce the risk of Alzheimer’s disease (AD) and other related dementias,” Kaddoumi summarizes. She’s partial to EVOO since it’s rich in phenols—which may provide additional benefits given their antioxidant and anti-inflammatory effects—whereas ROO is purified of phenols. Still, she acknowledges that the latter still clearly offers positive effects for brain health and beyond.
How to integrate olive oil into your diet
The Harvard study showed the highest impact against dementia-related mortality in those who consumed seven grams or more. “To put this in perspective, this is half a tablespoon—an amount that should be easy to consume in cooking, baking, grilling, frying, and in salads,” says Kyriakides. While he notes that any amount is better than none at all, you can gradually build your way up to bolster the liquid’s protective potential. “The first step to achieve the several benefits of olive oil is to introduce some into one’s diet and eventually increase to the 1.5- or two-tablespoon level,” he shares.
Kaddoumi adds that while her research shows that approximately two tablespoons of olive oil daily improved memory and modulated certain biomarkers related to AD, it’s difficult to determine the gold standard for intake given diverse contributing factors like genetics and environment.
All things considered, Kaddoumi suggests making a concerted effort to include olive oil in your daily diet. “Use it as a salad dressing, as an appetizer with breadsticks, or even prepare smoothies with olive oil,” she suggests.
For a bit of extra credit, you could also swap margarine and mayo for olive oil when appropriate: Per the Harvard study, this five-gram (one teaspoon) daily swap was associated with an eight to 14 percent lower risk of dementia mortality.
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