In short:
Recent research suggests that the type of olive oil you choose could be relevant to brain health, with growing interest in extra virgin olive oil and its naturally occurring polyphenols. But the evidence is still developing, so while EVOO looks like a sensible choice as part of a healthy diet, we can’t yet say that high-polyphenol olive oil prevents dementia or cognitive decline.
Not all olive oil is the same…
Put two bottles of olive oil next to each other in a UK supermarket and they might look pretty similar. But what’s inside can be very different.
One could be a light olive oil, which is typically a refined olive oil with a mild, neutral taste. The other could be a cold-pressed, early-harvest extra virgin olive oil with a peppery kick.
They’re both olive oils, but the difference between light olive oil vs extra virgin can mean very different things nutritionally. They don’t necessarily contain the same compounds or offer the same nutritional profile - and that difference is becoming increasingly important in brain health research.
Until recently, much of the research on olive oil and the brain looked at olive oil as a whole, without paying much attention to the type being consumed. So, when a study found a potential link between olive oil and cognitive health, it wasn’t always clear what kind of olive oil was behind the result.
Now, researchers are starting to ask a more useful question: does the type of olive oil matter? That’s the question we’re looking at in this article. We’ll explore what the latest studies are telling us about different types of olive oil, their polyphenols and what the research says about cognitive health and ageing.
Research notice
The studies below are summarised for educational purposes. They do not constitute an authorised UK or EU health claim for olive oil or olive oil polyphenols in relation to brain function, cognition or dementia risk.
Why the brain is a natural focus for olive oil research
As we get older, keeping our brains healthy becomes increasingly important. And researchers have long been interested in the role that diet could play in supporting cognitive health as we age.
Olive oil is particularly interesting because of the compounds it naturally contains. Extra virgin olive oil is rich in polyphenols such as hydroxytyrosol, oleuropein derivatives and oleocanthal. These compounds have antioxidant and anti-inflammatory properties, so researchers are investigating whether they could help support the brain against some of the processes associated with cognitive ageing.
We’ve explored polyphenols in more detail in our ultimate guide to high-polyphenol olive oil, including what they are, where they come from and how polyphenol levels vary between different oils.
One area of interest is oxidative stress. Despite making up only around 2% of our body weight, the brain uses a huge amount of our energy and oxygen - making it particularly vulnerable to oxidative damage over time. Inflammation is another area researchers are exploring, including whether olive oil’s polyphenols could help regulate it.
All of this research raises an important question: could olive oils with higher levels of these polyphenols have different effects from those containing very little? Well, that’s exactly the question nutritional scientists are beginning to explore…
What recent research actually shows
Five recent studies help give us a clearer picture of what the research is showing - and where the gaps still are.
1. Kaddoumi et al. (2022): Extra virgin vs. refined olive oil
One of the earlier studies to look at this question directly compared extra virgin olive oil with refined olive oil. The randomised trial involved 26 people with mild cognitive impairment; participants consumed either EVOO or refined olive oil, while researchers looked at cognitive function, brain activity and other markers of brain health.
What they found: The EVOO group showed improvements in some measures of cognitive and behavioural function, alongside changes in the blood-brain barrier and brain connectivity. Researchers also saw changes in blood markers linked to Alzheimer’s disease in both groups.
What does this mean? The study was small, so it’s not enough to draw firm conclusions. But it’s an interesting early sign that extra virgin and refined olive oil may not have exactly the same effects on the brain. It also gives some support to the idea that the polyphenols naturally found in EVOO could play a role.
2. Ni et al. (2026): Virgin oil vs. refined oil and cognitive decline
This recent study looked at 656 adults aged 55 to 75 with overweight or obesity and metabolic syndrome. Over two years, the researchers tracked their cognitive function alongside changes in their gut microbiome.
What they found: People who consumed more virgin olive oil tended to have better-preserved cognitive function and greater diversity in their gut microbiome. Those who consumed more “common” olive oil ( which mainly included refined and pomace oils) were linked with lower microbial diversity and greater cognitive decline. The researchers also identified changes in specific gut bacteria that could help explain the link.
How it compares with other research: This is some of the clearest evidence so far that the type of olive oil could be relevant to cognitive health, rather than olive oil simply being treated as one broad category. Unlike the small Kaddoumi trial, Ni et al. looked at a much larger group over two years and also considered the gut microbiome. It's an observational study, so it shows an association rather than proof that virgin oil causes better cognitive outcomes - but it's a meaningful change in how the research is being framed.
3. Gutiérrez-Romero et al. (2026): A first look inside the brain
This was a much smaller study, involving just nine healthy adults. Each participant had a month of daily polyphenol-rich extra virgin olive oil, followed by a month of regular olive oil. Researchers used brain imaging to see whether the two oils produced different effects.
What they found: After the month of polyphenol-rich EVOO, participants showed changes in brain activity - particularly in an area involved in visual processing. They also had higher levels of olive oil polyphenols in their urine, showing that their bodies had absorbed the compounds.
How it compares with other research: Where Ni et al. looked at real-world intake and cognitive outcomes over years, this study looks at what might be happening mechanistically, in the brain itself, over weeks. But nine participants is a very small sample, and the study measured changes in brain activity rather than changes in cognitive performance. Overall it’s an interesting finding, but much more research is needed to know whether these changes translate into meaningful benefits for brain health.
4. Simão et al. (2026): What the wider evidence shows
This systematic review and meta-analysis brought together five randomised trials involving 747 older adults with mild cognitive impairment or dementia. Rather than looking at one study in isolation, the researchers pooled the results to see what the wider evidence showed.
What they found: Across the trials, there were statistically significant improvements in some cognitive test scores, but the overall effect was small. The researchers also rated the certainty of the evidence as low, and the results changed depending on which studies were included in the analysis.
How it compares with other research: This puts the more promising findings into perspective. Ni et al. and Gutiérrez-Romero et al. both point toward a real, biological effect - but when researchers pool the strongest available trial evidence together, the overall benefit is small and the evidence is still limited. Taken together, the findings are encouraging, but they aren’t strong enough to show that EVOO improves cognitive health or treats cognitive decline.
5. Tessier et al. (2024): Olive oil and dementia-related mortality
One of the most well-known studies in this area comes from Harvard researchers. They followed more than 92,000 adults for up to 28 years, looking at olive oil consumption and dementia-related mortality.
What they found: People who consumed more than 7g of olive oil a day had a 28% lower risk of dying from dementia-related causes than those who rarely or never consumed it. This link remained even after researchers accounted for other factors that could affect dementia risk, including diet and genetics. They also found a lower risk when people used olive oil instead of margarine or mayonnaise - but not when it replaced butter or other vegetable oils. This is one reason comparisons such as vegetable oil vs olive oil are interesting when looking at the wider research.
How it compares with other research: Unlike the newer studies above, this research looked at olive oil as a whole rather than comparing different types. It also focused on the risk of dying from dementia, rather than changes in cognitive function or brain activity. So, while it can’t tell us whether virgin or polyphenol-rich olive oil is more beneficial, it provides useful context for the newer research looking at whether the type of olive oil makes a difference.
We’ve also covered this study and its findings in our guide to olive oil and longevity.
What current research suggests - and what it doesn't
The studies we’ve looked at point towards a more specific question: could the type of olive oil you choose influence its potential effects on brain health? That’s particularly interesting when we look at extra virgin olive oil and the natural polyphenols it contains.
Unlike refined olive oil, EVOO naturally contains compounds such as hydroxytyrosol and oleocanthal, and some of the newer research is specifically looking at oils that are richer in these polyphenols.
But there’s an important line between interesting evidence and proven health effects. There isn’t enough research yet to say that high-polyphenol EVOO prevents dementia or cognitive decline, and it shouldn’t be viewed as a treatment for either.
What we can say is that researchers are becoming more interested in whether the type of olive oil - and the polyphenols it contains - could help explain some of the differences seen in brain-health research. For now, adding EVOO to a healthy diet looks like a sensible choice while the research continues to develop.
What to look for when choosing an olive oil
The research above doesn’t give us a specific polyphenol level to aim for when it comes to cognitive health. But it does give us some useful things to look for when choosing an olive oil.
-
Extra virgin olive oil vs virgin olive oil: The two are different grades produced to different standards, with differences in how they’re made and the compounds they contain.
-
Look for a published polyphenol figure: There’s no established level linked to cognitive health, but a lab-tested figure in mg/kg tells you how much of these compounds are actually in the bottle.
-
Check the harvest date: A best-before date tells you when the oil should be used by, but the harvest date tells you when the olives were picked. That’s useful because polyphenol levels naturally decline over time and can be affected by heat and light.
-
Think about what the olive oil is replacing: The question of vegetable oil vs olive oil isn't simply about which is "healthier" - in the Tessier study, the association with lower dementia-related mortality was particularly clear when olive oil replaced margarine or mayonnaise.
If you want to dig further into what makes a good olive oil, we’ve covered it all in our complete guide to buying olive oil.
Where MasWorth comes in
We can’t tell you that high-polyphenol olive oil will protect your brain - in fact, no one can. The research simply isn’t there yet. But we can tell you exactly what’s in our oils.
Our MasWorth Family Groves and November Polyphenols EVOOs are made from early-harvest olives and cold-pressed to help ensure those naturally occurring compounds stay in the oil.
Family Groves and November Polyphenols are both independently lab-tested by the World Olive Centre for Health in Athens, with the polyphenol content and harvest date published for every bottle - so you can see exactly what you’re getting, rather than relying on what the label says.
Want to explore more of the research behind high-polyphenol olive oil? Our latest research on high-polyphenol olive oil looks at what scientists are finding across cognition, blood sugar, gut health and ageing. You can also read more about the wider research into olive oil, ageing and dementia-related mortality in our guide to olive oil and longevity.
Frequently Asked Questions
Is olive oil good for brain health?
Research has linked olive oil consumption with some positive brain-health outcomes, including lower dementia-related mortality in a large observational study. Other studies have found differences between virgin and refined olive oil. But this research does not prove that olive oil improves brain health or prevents cognitive decline, and there is no authorised UK health claim for these effects.
Is EVOO better than regular olive oil for the brain?
Recent research has found differences between virgin and refined olive oil, but we still don’t have enough evidence to say that extra virgin olive oil vs virgin olive oil produces different effects on brain health.
Is olive oil better than vegetable oil for the brain?
Research into vegetable oil vs olive oil is still developing, and different oils contain different types and amounts of compounds. The Tessier study found a lower risk of dementia-related mortality when olive oil replaced margarine or mayonnaise, but not when it replaced other vegetable oils. This doesn't establish that olive oil is better than vegetable oils for brain health.
What is olive oil cognition research actually measuring?
It depends on the study. Researchers have looked at things including cognitive test scores, brain activity, gut bacteria and dementia-related mortality. Because these studies measure different things, they don’t all tell us the same story.
What should I look for when choosing an olive oil?
There isn’t a proven polyphenol level linked to brain health. If you’re choosing an olive oil, look for extra virgin olive oil and, where available, a published polyphenol figure and harvest date. Our guide to buying olive oil explains what to look for on the bottle.
Scientific references
-
Kaddoumi A, Denney TS Jr, Deshpande G, Robinson JL, Beyers RJ, Redden DT, Praticò D, Kyriakides TC, Lu B, Kirby AN, Beck DT, Merner ND. Extra-Virgin Olive Oil Enhances the Blood-Brain Barrier Function in Mild Cognitive Impairment: A Randomized Controlled Trial. Nutrients. 2022 Dec 1;14(23):5102. doi: 10.3390/nu14235102. PMID: 36501136; PMCID: PMC9736478.
-
Ni J, Nishi SK, Babio N, Belzer C, Vioque J, Corella D, Hernando-Redondo J, Vidal J, Moreno-Indias I, Compañ-Gabucio L, Coltell O, Fitó M, Toledo E, Wang DD, Tinahones FJ, Salas-Salvadó J. Total and different types of olive oil consumption, gut microbiota, and cognitive function changes in older adults. Microbiome. 2026 Jan 24;14(1):68. doi: 10.1186/s40168-025-02306-4. PMID: 41578342; PMCID: PMC12910899.
-
Rocío M. Gutiérrez-Romero, Carolina Donat-Vargas, Emma Muñoz-Moreno, Alejandro Hinojosa-Moscoso, Polina Galkina, Camila Arancibia-Riveros, Inés Domínguez-López, Sara Hurtado-Barroso, Maria Pérez, Anna Vallverdú-Queralt, Rosa Casas, Ramón Estruch, Rosa M. Lamuela-Raventós; Resting-state brain connectivity following extra virgin olive oil intake in healthy adults: a randomised crossover pilot neuroimaging substudy. Food Funct. 2026; 17 (8): 3477–3483. https://doi.org/10.1039/d5fo05016b
-
Simão VC, Prudente TP, De Prado Lopes Oliveira A, De Oliveira C, Silveira EA. Effect of extra virgin olive oil on mild cognitive impairment and dementia in older adults: a systematic review and meta-analysis of clinical trials. Clin Nutr ESPEN. 2026 Jun;73:102977. doi: 10.1016/j.clnesp.2026.102977. Epub 2026 Feb 23. PMID: 41740793.
-
Tessier A, Cortese M, Yuan C, et al. Consumption of Olive Oil and Diet Quality and Risk of Dementia-Related Death. JAMA Netw Open. 2024;7(5):e2410021. doi:10.1001/jamanetworkopen.2024.10021
Scientific and nutritional information disclaimer
The information on this website is provided for educational and informational purposes only and summarises published scientific research and general nutritional information relating to olive oil and olive polyphenols. It is not intended as medical, nutritional or dietary advice and should not be relied upon as a substitute for advice from your doctor, registered dietitian or other qualified healthcare professional.
Scientific studies reflect the findings of their respective authors and should not be interpreted as evidence that the same results will occur for every individual or from the consumption of any particular product.
Any health claims made in relation to our products are limited to those expressly authorised under applicable UK and EU nutrition and health claims legislation.
