What Are Polyphenols? The Science Behind Premium Olive Oil

What Are Polyphenols? The Science Behind Premium Olive Oil

The term "extra virgin" tells you about the extraction process. It says almost nothing about nutritional value.

Polyphenols do.

What are polyphenols?

Polyphenols are naturally occurring antioxidant compounds found in olives. They're responsible for:

  • The peppery, slightly bitter finish of high-quality olive oil
  • Anti-inflammatory properties linked to cardiovascular health
  • The oil's resistance to oxidation (shelf stability)

The EU has approved a health claim: olive oils with ≥250 mg/kg of polyphenols can state they contribute to the protection of blood lipids from oxidative stress.

Why do levels vary so much?

Factor Effect on Polyphenols
Early harvest Higher — unripe olives contain more
Late harvest Lower — polyphenols convert to sugars
Heat during pressing Destroys polyphenols
Time since harvest Degrades over months
Storage conditions Light/heat accelerate loss

A supermarket EVOO might have 50–80 mg/kg. A properly harvested, cold-pressed early harvest oil can reach 400–600 mg/kg.

The label problem

Polyphenol content is not required on labels in most markets. You're expected to trust the "extra virgin" designation — which only measures acidity and sensory defects, not nutritional density.

Ask your olive oil producer for their lab results. If they don't have them, that's your answer.

Explore our early harvest oils →

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