Olive oil health benefits: what the evidence actually says

Which olive oil health claims are officially approved in the EU?

In the EU, general health claims on foods must come from the list in Commission Regulation (EU) No 432/2012, drawn up after assessment by the European Food Safety Authority (EFSA). Two listed claims are relevant to olive oil: ¹

The polyphenol claim rests on EFSA's 2011 opinion, which found a cause-and-effect relationship between olive oil polyphenols and protection of LDL particles from oxidative damage. EFSA also noted that the concentration in some olive oils may be too low to supply the 5 mg a day in a balanced diet. ²

So the claim is not automatic for every extra virgin olive oil. It depends on a measured polyphenol level. Twenty grams is about one and a half tablespoons. ⁶

What did the EU assessment not accept?

In the same 2011 opinion, EFSA looked at other claims for olive polyphenols and did not accept them: ²

• Maintenance of normal HDL (“good”) cholesterol: the evidence was insufficient.
• Maintenance of normal blood pressure: a cause-and-effect relationship was not established.
• “Anti-inflammatory properties”: EFSA treated this as a reference to treating diseases such as arthritis, which a food health claim is not allowed to make.

What did the PREDIMED trial find?

PREDIMED is a large randomised trial of a diet including extra virgin olive oil. In Spain, 7,447 people aged 55 to 80 at high cardiovascular risk, but without heart disease, were assigned to a Mediterranean diet with extra virgin olive oil, a Mediterranean diet with mixed nuts, or a control diet with advice to reduce fat. Median follow-up was 4.8 years. ³

The trial's first report (NEJM, 2013) was retracted in June 2018 after the authors found problems with randomisation at some sites, including household members enrolled without randomisation. A corrected analysis, which does not assume every participant was randomised, was published in its place and still found fewer events in both Mediterranean diet groups. ^3,4

What it does not show: the effect of olive oil on its own, since the whole diet changed; results for people at low risk; or anything outside the study's population. It compared the Mediterranean diet with a low-fat diet, not with no diet at all.

What does the US FDA allow?

The FDA has not authorised a full health claim for olive oil. It allows two “qualified” claims, whose wording must say the evidence is limited or not conclusive: ^5,6

• 2004, olive oil: “Limited and not conclusive scientific evidence suggests that eating about 2 tablespoons (23 grams) of olive oil daily may reduce the risk of coronary heart disease due to the monounsaturated fat in olive oil. To achieve this possible benefit, olive oil is to replace a similar amount of saturated fat and not increase the total number of calories you eat in a day.” ⁵
• 2018, oils high in oleic acid: “Supportive but not conclusive scientific evidence” that about 1½ tablespoons (20 g) a day of oils with high levels of oleic acid, replacing fats higher in saturated fat, may reduce the risk of coronary heart disease. It applies to oils with at least 70% oleic acid. ⁶

The International Olive Council's trade standard allows olive oils an oleic acid content of 55 to 85%, so whether a particular olive oil qualifies for the 2018 claim depends on its measured fatty acid profile. ⁷

Is olive oil anti-inflammatory? What is oleocanthal?

Oleocanthal is a compound in newly pressed extra virgin olive oil. It was named in a 2005 study in Nature that started from a taste observation: its sting at the back of the throat feels like that of liquid ibuprofen. The researchers then showed in lab tests that oleocanthal, like ibuprofen, inhibits the COX-1 and COX-2 enzymes involved in inflammation. ⁸

That is a laboratory finding, not a medical effect in people. The authors estimated that 50 g a day of an oil with up to 200 µg of oleocanthal per ml would supply about a tenth of the ibuprofen dose used for adult pain relief, and they presented a long-term health effect as a possibility only. ⁸ Olive oil is not a painkiller, and EFSA has not accepted an anti-inflammatory claim for olive polyphenols. ²

What do long-term observational studies show?

A 2022 study followed 60,582 women and 31,801 men in the United States for 28 years. Those who ate more than half a tablespoon (7 g) of olive oil a day had a lower risk of death from any cause over the period than those who never or rarely ate it (hazard ratio 0.81, about 19% lower). When olive oil was compared with other vegetable oils combined, no significant difference was found. ⁹

Studies like this show an association, not proof of cause: people who use more olive oil may differ in other ways. They are useful signals, weaker than a randomised trial.

What is not proven?

• That olive oil treats or cures any disease.
• That olive oil alone, outside an overall healthy diet, prevents heart disease.
• That olive oil reduces inflammation or pain in people the way a medicine does.
• That any particular bottle meets the EU polyphenol claim, unless a lab has measured at least 5 mg of hydroxytyrosol and its derivatives per 20 g.

What does this mean for Leptis Magna?

Leptis Magna is a Libyan extra virgin olive oil: cold pressed, early harvest and with free acidity of 0.4% or less. We have not yet published lab results for its hydroxytyrosol level, so we do not make the EU polyphenol claim for it. We will add the figure, with the lab report, once it is available.

The evidence above is about using olive oil in place of fats higher in saturated fat, within a healthy diet overall. To judge its freshness yourself, read how to taste olive oil.