What are polyphenols?

They’re a defence against sun, pests and disease, and olives make a lot of them. Crush the fruit cold and quickly, and some of those compounds end up in the oil instead of being washed away or refined out.

More than thirty phenolic compounds have been identified in extra virgin olive oil. Together they act as antioxidants, and they’re the part of olive oil that almost every health study measures.

Every polyphenol figure on this site is written the same way: milligrams of polyphenols in each kilogram of oil. It’s the concentration. A tablespoon holds about 14g of oil, so what you take in each day depends on the number on the bottle and how much you pour.

• 20g × 250 mg/Kg 5 mg The EU health claim minimum
• 2 tbsp × 500 mg/Kg ≈ 14 mg Easy to use freely, every day
• 1 tbsp × 1,000 mg/Kg ≈ 14 mg Same dose from half the oil

The trials behind the EU health claim compared oils at low, medium and high polyphenol levels, and the benefit to blood lipids rose in step with polyphenol content. Source The catch: the strongest oil in those trials was under 400 mg/Kg. Oils at 1,000 mg/Kg and above haven’t been studied the same way yet, so nobody can say whether the effect keeps climbing.

“High polyphenol” is a marketing phrase, not a legal term, and nothing stops a producer using it. In practice, 250 mg/Kg is the line that matters: it’s where an oil qualifies for the EU health claim. Here’s roughly how the shelf breaks down.

1. Refined or “light” ≈ 0 mg/Kg Refining strips the polyphenols out along with the flavour.
2. Supermarket extra virgin 50–150 mg/Kg Legally extra virgin, but usually blended, older and mild.
3. Good extra virgin 150–250 mg/Kg Fruity and a little bitter. Still below the health claim.
4. 250 mg/Kg · EU health claim
5. True high polyphenol 250–500 mg/Kg Qualifies for the health claim. Distinctly bitter and peppery.
6. Ultra high polyphenol 500–1,500+ mg/Kg Early harvest, single cultivar, fresh. This is what we track.

Bars are illustrative, not to scale. Every oil on this site publishes its own tested figure. See the full table in the EVOO Score rankings.

The figure on a lab report is a total of dozens of compounds. A handful of them do most of the work.

Olive oil polyphenols are one of the more heavily studied areas in nutrition. The honest summary: the evidence is promising, and still developing.

This page is general information about food, not medical advice. Olive oil isn’t a treatment for any condition. If you’re managing one, speak to your GP.

Six things decide whether a bottle lands at 80 mg/Kg or 800, and most are settled long before the oil reaches a shelf.

1. 01

   Harvest timing

   Green, early harvest olives are packed with polyphenols. Ripe olives give far more oil but a fraction of the phenolics. The biggest lever, and the most expensive.

2. 02

   Cultivar

   Some varieties are simply richer. Coratina, Picual, Koroneiki and Moraiolo top the table. Blends tend to average out.

3. 03

   Milling

   Warmer, longer processing extracts more oil but degrades polyphenols. Serious producers mill cold and fast, often within hours of picking.

4. 04

   Age

   Polyphenols fall from the day the oil is made. A 750 mg/Kg oil at bottling isn’t a 750 mg/Kg oil two years later.

5. 05

   Storage

   Light, heat and oxygen break polyphenols down. Dark glass or tins, a cool cupboard and a sealed cap protect what you paid for.

6. 06

   Filtration

   Unfiltered oil keeps water and sediment in the bottle, which speeds up decline. Filtered oil holds its numbers, and scores better on EVOO Score.