What Polyphenols Actually Are — and What the Evidence Says
Extra virgin olive oil is a fat. What separates a commodity supermarket bottle from a high-polyphenol oil is not the fat, it is the phenolic fraction — and that fraction is measurable. This page gives you the numbers, the regulation, and the limits of what the research supports.
High-polyphenol EVOO is not a marketing tier. It is a measurement.
Any oil that meets the legal limits — free acidity at or below 0.8%, plus a passing sensory panel — can be sold as "extra virgin." Neither test says anything about polyphenol content. Two oils can both be legally extra virgin and differ by a factor of ten in their phenolic load.
Polyphenols are the bioactive compounds that give high-quality olive oil its bitterness and its peppery sting at the back of the throat. They are also what degrades first — with time, light, heat, and slow milling.
A standard supermarket extra virgin olive oil typically measures between 50 and 150 mg/kg total polyphenols. Oils described in the literature as "high-polyphenol" generally sit above 250 mg/kg. Only a small minority of commercial oils exceed 500 mg/kg.
The only way to know where a bottle sits is a laboratory report tied to a specific harvest and a specific lot. A number on a label with no harvest date and no report number is not verifiable.
The macronutrients are identical. The phenolic fraction is not.
Olive oil is pure fat: no protein, no carbohydrate, no fibre, no cholesterol. Roughly 120 calories per tablespoon (15 ml), all of it fat, of which about 70–75% is monounsaturated oleic acid. That profile is essentially the same whether the oil cost six dollars or sixty.
What differs is everything measured below the fat line.
Oleocanthal is one compound, not a category. Some producers report the sum of several secoiridoid compounds and label the total as "oleocanthal," which inflates the figure several times over. Our report separates them: 85 mg/kg oleocanthal, 50 mg/kg oleacein, within a total phenolic content of 629 mg/kg for the October 2025 harvest, lab report #37823.
The EFSA olive oil polyphenols health claim (5 mg hydroxytyrosol per 20 g): what it says — and what it does not
In 2012 the European Food Safety Authority reviewed the clinical evidence on olive oil polyphenols and authorised a single, narrowly worded claim under EU Regulation 432/2012.
"Olive oil polyphenols contribute to the protection of blood lipids from oxidative stress."
Permitted only for oils containing at least 5 mg of hydroxytyrosol and its derivatives per 20 g of oil, and only when the consumer is informed that the effect is obtained with a daily intake of 20 g of olive oil.
Read that condition carefully, because almost every marketing page online gets it wrong. The threshold is expressed in hydroxytyrosol and its derivatives. That is a specific analytical fraction. It is not the same measurement as total polyphenols, and the two numbers cannot be converted into one another.
Deliba Ottobratico is tested at 629 mg/kg total polyphenols for the October 2025 harvest, lab report #37823. That is a total polyphenol figure.
We have not yet commissioned the separate determination of hydroxytyrosol and its derivatives on this lot. Until we have that number in hand, we do not state that our oil meets the EFSA condition — because we would be inferring it from a different measurement, and inference is not evidence.
When the analysis is completed, the result will be published here whether or not it is favourable.
Deliba Ottobratico — October 2025 harvest · 629 mg/kg total polyphenols · laboratory report #37823. Single-estate, Cold-Extracted within 4 hours of harvest in Molochio, Calabria, Southern Italy.
Polyphenol benefits: what the research actually shows — and where it stops
The two areas below are the ones where the published work on olive oil polyphenols is strongest. They describe findings about polyphenols as a class of compounds, studied in clinical and laboratory settings. They are not statements about what any particular bottle will do for any particular person.
Protection of blood lipids from oxidation
This is the mechanism underlying the EFSA-authorised wording. Trials comparing higher-polyphenol to lower-polyphenol olive oil — matched for fat profile, so the phenolic content is the only variable — have examined markers of lipid oxidation. A systematic review and meta-analysis of this literature was published in Critical Reviews in Food Science and Nutrition.
Oleocanthal and the throat sensation
In 2005, researchers publishing in Nature reported that oleocanthal, a compound found in extra virgin olive oil, produced a stinging sensation at the back of the throat and showed activity on the COX-1 and COX-2 enzymes in laboratory assays. This is a chemical characterisation, made in vitro. It does not make olive oil a substitute for any medication.
Most trials comparing high- and low-polyphenol olive oil run for four to twelve weeks and measure biomarkers, not clinical outcomes. Long-term studies with hard endpoints come largely from research on the Mediterranean dietary pattern as a whole, in which olive oil is one component among many — not from isolated polyphenol intake.
This page is educational. Nothing on it is medical advice, and nothing here should inform a decision about treatment or medication. If you have a specific health condition, that conversation belongs with your physician.
What actually differs between two extra virgin olive oils
Rigorous trials do not compare olive oil to no olive oil. They compare high-polyphenol oil to low-polyphenol oil with the same fat profile, which isolates the phenolic variable. The table below applies the same logic to what is on a shelf.
Three factors drive the phenolic content: cultivar — the Ottobratica variety is naturally rich in polyphenols; harvest timing — picking in October, while the fruit is still green, preserves the phenolic load at the cost of yield; and milling speed — the olives reach the mill within four hours, before oxidation begins.
How to get the phenolic content into the food
Polyphenols degrade with heat and with time in an open bottle. Three practical points follow directly from that chemistry.
Frequently asked questions
What is high-polyphenol olive oil?
An extra virgin olive oil whose measured total polyphenol content is substantially above the commercial average. Standard supermarket oils typically fall between 50 and 150 mg/kg; oils described as high-polyphenol in the literature generally sit above 250 mg/kg. The category is defined by measurement, not by label language — which is why the figure is only meaningful when it is tied to a harvest date, a lot, and a laboratory report. See the full guide →
What is oleocanthal, and why do people notice it in the throat?
Oleocanthal is a single phenolic compound found in extra virgin olive oil. It is responsible for the characteristic stinging sensation at the back of the throat that fresh, high-quality oil produces. Deliba Ottobratico from the October 2025 harvest was measured at 85 mg/kg oleocanthal within 629 mg/kg total polyphenols, laboratory report #37823. Be cautious with oleocanthal figures elsewhere: some are the sum of several distinct compounds reported under one name. Read the oleocanthal guide →
How many calories are in olive oil per tablespoon?
Approximately 120 calories per tablespoon (15 ml), entirely from fat. This does not vary meaningfully between grades or price points. The fat profile is roughly 70–75% monounsaturated oleic acid, with smaller amounts of polyunsaturated and saturated fat. Olive oil contains no carbohydrate, protein, fibre, or cholesterol.
What vitamins are in olive oil?
Vitamin E, at roughly 1.9 mg per tablespoon (about 13% of the daily value), and vitamin K, at roughly 8 µg per tablespoon (about 7% DV). Olive oil is not a meaningful source of vitamin C, B vitamins, vitamin D, or minerals.
Does cooking destroy the polyphenols in olive oil?
Heat reduces phenolic content; it does not eliminate it at moderate temperatures. Published work indicates that extra virgin olive oil retains a meaningful phenolic fraction through sautéing and roasting up to roughly 180°C (356°F), with more substantial degradation above 200°C. For maximum phenolic delivery, use the oil raw. For daily cooking, Sinopolese is the oil we make for the job.
What does the EFSA olive oil polyphenol claim require?
Under EU Regulation 432/2012, the authorised wording is that olive oil polyphenols contribute to the protection of blood lipids from oxidative stress. It may be used only for oils containing at least 5 mg of hydroxytyrosol and its derivatives per 20 g of oil, and the consumer must be told the effect relates to a daily intake of 20 g. Note that this condition is expressed in a specific analytical fraction — not in total polyphenols. The two are different measurements and one cannot be derived from the other. We have not yet run that specific determination on our current lot, so we make no statement about qualifying for it.
How can I verify a polyphenol number before buying?
Ask for three things together: the harvest date, the measured value, and the laboratory report number for that specific lot. Any one of them alone is unverifiable. A figure with no harvest date could describe oil pressed years ago; a figure with no report number cannot be checked at all. Our current figures are: Ottobratico, October 2025 harvest, 629 mg/kg total polyphenols, report #37823; Sinopolese, November 2025 harvest, 609 mg/kg total polyphenols, report #37839. Both reports are published in full →
What are the benefits of high-polyphenol olive oil?
The strongest published evidence concerns polyphenols as a class of compounds: controlled trials comparing higher- to lower-polyphenol olive oil have examined markers of lipid oxidation, and EFSA has authorised one narrowly worded claim on that basis — see the regulation section above. Those are findings about compounds studied in research settings, not promises about what any bottle will do for any person. What a high-polyphenol oil gives you, verifiably, is a measured phenolic content: in our case, October 2025 harvest · 629 mg/kg total polyphenols · laboratory report #37823, published before purchase.
Which Deliba oil should I choose?
Ottobratico is the finishing oil — fresh and smooth with a distinct peppery finish, made to be used raw at the end of cooking. Sinopolese is the everyday oil — light-fruity and delicate with almond notes, for sautéing, pasta and daily cooking. Sinopolese is currently on pre-order for the November 2026 harvest. If you want both, the Duo pairs them. Free standard US shipping applies from 4-bottle boxes.
Related guides and reports
Every number on this page has a report behind it.
October 2025 harvest · 629 mg/kg total polyphenols · laboratory report #37823Deliba Ottobratico is a single-estate extra virgin olive oil made from 100% Ottobratica olives grown in Molochio, Calabria, Southern Italy, cold-extracted within four hours of harvest. The full laboratory analysis is published before you buy, not after.