One of the most powerful polyphenols in olive oil is hydroxytyrosol. Consuming hydroxytyrosol is linked to benefits in neurological, cardiovascular, and metabolic health, and the compound has demonstrated anti-inflammatory, anti-cancer, neuro-protective, and immuno-protective effects. A recently published scientific review in the journal Foods examines the growing body of evidence supporting the characterization of hydroxytyrosol as a “functional food,” with emphasis on its effects on neurological and cognitive processes.
What is it?
Hydroxytyrosol (hi-droxy-TY-roh-sol), abbreviated as HXT, is a phenol, a natural chemical that is both water-soluble and attracted to fats, which means that it can pass through cell membranes. Its chemical structure also explains its strong antioxidant and anti-inflammatory properties. HXT occurs mainly in olives—olive oil, fruit, leaves, and pulp—as well as in red and white wines.
What does HXT do in the brain?
HXT interacts with the brain and its vascular (blood vessel) system in 3 ways: 1) as an antioxidant and anti-inflammatory agent, HXT helps prevent damage to cerebral blood vessels and improves their function; 2) lab studies show that, by reducing oxidation and inflammation, HXT helps maintain the proper functioning of the blood-brain barrier (BBB), a crucial filter inside the brain’s blood vessels that controls what substances enter and exit the brain; 3) in studies in humans, consuming HXT in the form of high-phenolic EVOO resulted in less “leakage” across the BBB and, as reflected in participants’ performance on cognitive tests, improved connectivity between brain regions.
HXT and its metabolites (the components of a substance that are formed when metabolic processes, such as digestion, break it down) are able to cross the BBB to interact with specific brain processes, enhancing protective activity and dampening inflammatory activity that is linked to depression and cognitive decline.
How much HXT is needed to obtain its benefits?
In studies in humans, the above benefits were observed with an HXT intake ranging from 7 to 15 mg/day. In terms of EVOO, this translates to a daily consumption of about 25 to 50 ml of high-phenolic olive oil, or ~2 to 3 tablespoons. Table olives—regardless of their color or brining—also provide an excellent source of HXT.
What’s next for HXT?
This body of promising evidence has intensified interest in the development of HXT-enriched foods and other ways of delivering this health-promoting compound. HXT is highly bioavailable, which means that, after it is consumed and digested, it is readily absorbed and transported by the body. So, for now—perhaps for always—the most effective, efficient, and delicious way to obtain the neuroprotective benefits of HXT is “food-first,” via high-phenolic EVOO.
Reference: Martínez-Zamora Z. Foods 2025;14(21):3624.