Olive oil

What it is and how to eat it

Olive oil is pressed from the fruit of the olive tree, and the EU allows only four categories to be sold to consumers: extra virgin and virgin olive oil, obtained solely by mechanical or other physical means (extra virgin with a maximum acidity of 0.8 g per 100 g), "olive oil", a blend of refined and virgin oils, and olive-pomace oil (Regulation (EU) No 1308/2013). In Spain it is the everyday cooking fat, while in Latin America it shares the kitchen with sunflower, corn or canola oil. This page uses USDA's generic entry, which does not distinguish categories, with 884 kcal, 100 g of fat and 73 g of monounsaturated fat per 100 g.

The 10 g serving, about two teaspoons, provides 88 kcal and no protein: it is for cooking and dressing the protein and vegetables on the plate, not for replacing them. The 2025 nutrition advisory on GLP-1 therapy lists olive oil among the plant oils to encourage, but suggests avoiding fatty foods in the first few days of treatment as well as large or high-fat meals; in those days, and after each dose increase, measure it with a spoon instead of pouring freely and leave fried foods and very oily stews for later. Used sparingly like that, it goes into recipes such as the Spanish vegetable pisto with eggs or the fresh cod with tomato sauce and potato.

What the evidence says

The EU authorizes the claim "olive oil polyphenols contribute to the protection of blood lipids from oxidative stress" only for olive oil with at least 5 mg of hydroxytyrosol and its derivatives per 20 g, with consumers told that the effect is obtained with a daily intake of 20 g of olive oil, about 177 kcal (Regulation (EU) No 432/2012); the USDA entry does not measure polyphenols, and an oil without that claim on the label does not necessarily reach that amount. In the PREDIMED trial, 7,447 people aged 55 to 80 at high cardiovascular risk in Spain followed a Mediterranean diet with extra virgin olive oil (they received 1 liter a week for the household), a Mediterranean diet with nuts, or a control diet with advice to cut fat; after a median of 4.8 years, the olive oil group had fewer heart attacks, strokes or cardiovascular deaths than the control group (3.8% vs 4.4%, a 31% lower relative risk), an effect of the whole diet and not of the oil alone. The first version, from 2013, was retracted and republished in 2018 in the New England Journal of Medicine after randomization problems were found, such as enrolling household members without randomizing them, and the results were similar after excluding the 1,588 participants affected. It was funded mainly by Spain's Instituto de Salud Carlos III, and the oil was donated by Hojiblanca and Patrimonio Comunal Olivarero.

The sources for this section are listed under "Sources" at the end of the page.