Polyphenols and health
What makes olive oil healthy, and which claims are scientifically approved?
4 min read
A great deal is said about olive oil and health, and not all of it rests on the same evidence. Let's separate out the part that does.
Fatty acid composition
Roughly 55–83% of olive oil is oleic acid — a monounsaturated fatty acid. This is one of the main reasons it is the backbone fat of Mediterranean cooking.
Polyphenols
The olive's own defence compounds — hydroxytyrosol, tyrosol, oleocanthal, oleuropein — pass into the oil. The bitterness and the peppery catch in the throat come directly from them, which means your palate is, in effect, taking a measurement.
The approved health claim
The European Food Safety Authority (EFSA) has approved a single claim for olive oil polyphenols: "olive oil polyphenols contribute to the protection of blood lipids from oxidative stress." To use it, the product must contain at least 5 mg of hydroxytyrosol and its derivatives per 20 g (roughly 250 mg/kg).
How refined oil differs
Most polyphenols are lost during refining. So products labelled plain "olive oil" are, despite a similar fatty acid profile, not equivalent to extra virgin in antioxidant content.
Why early harvest matters
As olives ripen, oil yield rises but polyphenols fall. Early harvest means less oil per tonne of fruit but higher polyphenols. That trade-off between quality and yield is the decision that separates a serious producer.
The information on this page is general in nature and is not a substitute for medical advice. Consult your doctor about decisions concerning your health.
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