Bioactivity (D1 Index) — Classifying Olive Oils by Their Therapeutic Potential

Not all extra virgin olive oils are created equal. Two oils that look identical in the bottle can differ tenfold or more in their content of health-promoting compounds. To make this difference transparent for our customers, we classify every certified high phenolic olive oil in our collection according to its D1 index — a precise, laboratory-measured parameter recognized by leading olive oil researchers worldwide.

What Is the D1 Index?

The D1 index is the sum of oleocanthal and oleacein concentrations (expressed in mg/kg) measured in extra virgin olive oil using quantitative NMR or HPLC methods. These two secoiridoid compounds are the most biologically active phenolics in EVOO and the primary drivers of its anti-inflammatory and antioxidant effects:

• Oleocanthal — discovered in 2005 by Beauchamp and colleagues to act similarly to ibuprofen, inhibiting the COX-1 and COX-2 enzymes responsible for inflammation (Nature, 2005). It causes the characteristic peppery, throat-tickling sensation in fresh, high-quality EVOO.
• Oleacein — closely related to oleocanthal, with documented antioxidant, cardioprotective, and neuroprotective activity. Research suggests it may help protect against the development of Alzheimer's disease and metabolic syndrome.

The D1 index was established as a benchmark by the National and Kapodistrian University of Athens (Prof. Prokopios Magiatis, World Olive Center for Health) and is referenced in the international research collaboration with the University of California, Davis. Reference average values in this global study are approximately 135 mg/kg of oleocanthal and 105 mg/kg of oleacein — meaning a typical "good" EVOO has a D1 of around 240 mg/kg.

Our Four Bioactivity Tiers

Based on the D1 index, we have organized our certified high phenolic olive oils into four clearly defined tiers. Each tier corresponds to a different level of bioactive content and suggests different uses — from everyday gourmet consumption to therapeutic, health-focused supplementation.

The D1 Index and the EU 432/2012 Health Claim

The European Union's Commission Regulation (EU) No 432/2012 permits an official health claim for olive oils containing at least 5 mg of hydroxytyrosol and its derivatives per 20 g of oil — meaning "Olive oil polyphenols contribute to the protection of blood lipids from oxidative stress." All four of our bioactivity tiers comfortably exceed this regulatory threshold. The D1 index goes one step further, distinguishing between oils that merely qualify for the EU health claim and oils that offer substantially elevated therapeutic potential.

How We Verify Each Oil

Every product classified by D1 in our collection comes with a certificate of analysis from an accredited laboratory — primarily the National and Kapodistrian University of Athens (qNMR method, Magiatis protocol published in J. Agric. Food Chem. 2012 and 2014, and Molecules 2020). The certificate is available on each product page, so you can verify the exact oleocanthal, oleacein, hydroxytyrosol, tyrosol, oleuropein aglycon, ligstroside aglycon, and total polyphenol concentrations — not just take our word for it.

Browse by Bioactivity Tier

Choose the bioactivity level that matches your goals:

Note: The D1 index is not a regulatory parameter but a scientific classification used to communicate the bioactive potential of olive oil in a transparent way. The recommended daily intake of EVOO for cardiovascular benefit, according to the FDA and the Mediterranean diet research, is approximately 2 tablespoons (23 g) per day.