Tyrosol is a simple, stable phenolic compound in olive oil and the close chemical cousin of hydroxytyrosol. It occurs in olive fruit, extra virgin olive oil and, in smaller amounts, white wine. It is a weaker antioxidant than hydroxytyrosol, but it is very stable and well absorbed. It is named in the EU olive oil health claim as one of the derivatives that count toward protecting blood lipids from oxidative stress.

What is tyrosol?

Tyrosol is a phenylethanoid, a small phenolic alcohol. It has the same backbone as hydroxytyrosol but one fewer hydroxyl group on its ring. That missing group is the whole difference. It makes tyrosol less reactive, which means a weaker direct antioxidant but a longer-lasting one.

In the olive, tyrosol mostly sits inside larger molecules. Ligstroside, its main parent compound, contains a tyrosol unit. When olives are crushed, ligstroside breaks down into oleocanthal and related forms, which also carry that tyrosol unit. Further breakdown in the oil or in the gut releases free tyrosol.

Tyrosol has little taste of its own. Its stability means it lasts longer in stored oil than reactive compounds such as oleacein. That is why it is sometimes called the quiet partner of the olive phenolic family.

How it works in the body

Tyrosol can neutralise free radicals, though less efficiently than hydroxytyrosol. Its strength is persistence. Because it is stable, it can build up inside cells and help protect them over time, according to laboratory studies.

The more interesting finding concerns what the body does with it. Human research suggests that some tyrosol is converted into hydroxytyrosol in the body, by liver enzymes from the cytochrome P450 family. If confirmed, this means tyrosol may act partly as a slow source of the stronger antioxidant. Tyrosol also appears to support the healthy function of blood vessel linings in early studies.

What the research shows

The EU regulation names tyrosol. The authorised EU claim states that olive oil polyphenols contribute to the protection of blood lipids from oxidative stress. The regulation applies it to oils with at least 5 mg of hydroxytyrosol and its derivatives per 20 g, and lists tyrosol as an example of those derivatives (Commission Regulation (EU) No 432/2012). This follows the EFSA scientific opinion (EFSA NDA Panel, EFSA Journal, 2011).

Absorption in people. A human study found that tyrosol and hydroxytyrosol from olive oil are absorbed in proportion to the amount consumed (Visioli et al., FEBS Letters, 2000). Higher-phenolic oil therefore delivers more of both.

Conversion to hydroxytyrosol. A randomised controlled trial gave volunteers tyrosol in white wine and measured the results (Boronat et al., Free Radical Biology and Medicine, 2019). The authors reported that part of the tyrosol was converted into hydroxytyrosol, along with favourable changes in some cardiovascular markers. It was a small trial and needs confirmation.

Cell protection. In cell and animal models, tyrosol has been reported to protect cells from oxidative injury and to reduce inflammatory signalling (preclinical). These results explain the interest. They do not show effects in people.

How much is in olive oil and in Phenolia

Free tyrosol in extra virgin olive oil is typically low, from a few to a few tens of mg/kg. Much more is present in bound form, inside ligstroside-type compounds such as oleocanthal. Free tyrosol often rises slightly as an oil ages, as larger compounds break down. That makes it a poor marker of freshness on its own.

Total levels still follow the usual pattern. Early harvest green olives contain more of the parent compounds. The Greek Koroneiki cultivar is known for high secoiridoid content. Cold, careful extraction keeps more of them intact.

Pomoni measures each compound by HPLC (high-performance liquid chromatography), which separates tyrosol from hydroxytyrosol and the larger secoiridoids. See HPLC vs NMR for why separating them matters.

Pomoni High-Phenolic Olive Oil is made from early harvest Koroneiki olives. Phenolia Daily combines high-phenolic olive oil (powdered), olive leaf extract and Greek Mountain Tea. The current batch certificate on testing and certifications lists the measured figures. For the bigger picture, read how polyphenols work at a cellular level.

Related compounds

• Hydroxytyrosol
• Oleocanthal
• Oleuropein
• Oleacein
• The science of polyphenols
• HPLC vs NMR testing

Frequently asked questions

These statements have not been evaluated by the Food and Drug Administration. Pomoni products are not intended to diagnose, treat, cure or prevent any disease.

Sources

1. Commission Regulation (EU) No 432/2012 establishing a list of permitted health claims made on foods. Official Journal of the European Union. 2012. eur-lex.europa.eu
2. EFSA Panel on Dietetic Products, Nutrition and Allergies. Scientific Opinion on the substantiation of health claims related to polyphenols in olive and protection of LDL particles from oxidative damage. EFSA Journal. 2011;9(4):2033. doi:10.2903/j.efsa.2011.2033
3. Visioli F, Galli C, Bornet F, et al. Olive oil phenolics are dose-dependently absorbed in humans. FEBS Letters. 2000;468(2-3):159-160. doi:10.1016/s0014-5793(00)01216-3
4. Boronat A, Mateus J, Soldevila-Domenech N, et al. Cardiovascular benefits of tyrosol and its endogenous conversion into hydroxytyrosol in humans. A randomized, controlled trial. Free Radical Biology and Medicine. 2019;143:471-481. doi:10.1016/j.freeradbiomed.2019.08.032