🧪 Oleic acid

Oleic acid is a monounsaturated fatty acid with 18 carbon atoms and one double bond, and the main fatty acid of olive oil. Chemists call it cis-9-octadecenoic acid, and its formula is C18H34O2. It melts at about 13 °C, so it is liquid at room temperature.

Genuine olive oil has to contain 55 to 85 per cent oleic acid among all its fatty acids. This range is part of the International Olive Council standard and EU rules and helps to detect fraud. According to USDA data, 100 grams of olive oil contain about 71 grams of oleic acid, while ordinary sunflower oil contains about 45 grams.

Oleic acid is not found only in olives: there is plenty of it in avocados, nuts and seeds, as well as in cheese, eggs, meat and milk.

Regulators are cautious about its benefits. In the EU it may be stated that replacing saturated fats with unsaturated fats helps maintain normal cholesterol, and oleic acid is an unsaturated fat. In 2018 the US Food and Drug Administration allowed a qualified claim: about 20 grams a day of oils with at least 70 per cent oleic acid, used instead of saturated fats, may reduce the risk of coronary heart disease, although the evidence is not conclusive.