Olive Oil
Olive Oil: Nutrition, History and Complete Cooking Guide
Olive oil is one of humanity's oldest and most culturally significant foods — the extraction and use of olive oil predates written history, with archaeological evidence of olive oil production in the eastern Mediterranean dating to at least 8,000 years ago. The olive tree (Olea europaea) was so central to the economies, cultures, and religions of ancient Greece, Rome, and the Levant that it is difficult to overstate its importance: olive oil was food, fuel for lamps, medicine, cosmetic, and a medium of trade. The ancient Greek economy was built substantially on olive oil exports; the Romans spread olive cultivation throughout the Mediterranean world and beyond; the Old Testament is saturated with olive symbolism. Today, olive oil remains the defining fat of the Mediterranean diet — the dietary pattern associated with the most consistent and compelling evidence for long-term health outcomes in nutritional epidemiology. Italy, Spain, and Greece are the dominant producers; extra virgin olive oil from these countries — cold-pressed from fresh olives within hours of harvest — is one of the most flavour-variable and complex of all culinary oils.
Nutritional Value and Fat Composition
Olive oil provides 884 kcal and 100 g of fat per 100 g. The fat is approximately 73% monounsaturated (predominantly oleic acid, omega-9), 14% saturated, and 11% polyunsaturated — a fat composition associated with cardiovascular benefit and chemical stability during cooking. Extra virgin olive oil contains up to 500 mg of polyphenols per kilogram — including oleocanthal (with anti-inflammatory properties comparable to ibuprofen, according to research by Gary Beauchamp), oleuropein, and hydroxytyrosol. These polyphenols are largely absent from refined olive oil. Vitamin E (particularly alpha-tocopherol) is present in meaningful amounts.
Health Evidence — The Mediterranean Diet Connection
Olive oil is the dietary fat with the strongest epidemiological and clinical trial evidence for health benefit. The PREDIMED trial — a landmark randomised controlled trial involving nearly 7,500 participants at high cardiovascular risk — found that supplementing a Mediterranean diet with extra virgin olive oil (at least 4 tablespoons daily) reduced major cardiovascular events by approximately 30% compared to a control low-fat diet. The Lyon Diet Heart Study found similar results. Multiple meta-analyses have confirmed associations between olive oil consumption and reduced cardiovascular disease, reduced all-cause mortality, and reduced risk of type 2 diabetes. The evidence is stronger for extra virgin olive oil than for refined olive oil, with polyphenol content likely responsible for the additional benefit beyond oleic acid alone.
How to Select, Store and Use Olive Oil
Always use extra virgin olive oil for cold applications — dressings, dipping, finishing dishes. For cooking, extra virgin olive oil is suitable up to approximately 180–190°C despite persistent myths suggesting it cannot be used for cooking; its polyphenol content actually improves stability during moderate-heat cooking. For deep-frying above 190°C, a refined light olive oil or neutral oil may be preferable. Store in a dark bottle or tin away from heat and light — polyphenols degrade in UV light. Use within a year of harvest date. Choose oil with a harvest date (not just best-before) and a provenance — single-estate and single-variety oils have the most character.
Olive oil is the only common cooking oil that is a fruit juice. It is pressed mechanically from whole olives without solvents or refining, which is why extra virgin olive oil carries flavour, aroma and polyphenols that a seed oil extracted with heat and hexane does not. The grades are legally defined and worth understanding. Extra virgin must be mechanically extracted, below 0.8% free acidity, and free of sensory defects on a tasting panel. Virgin allows up to 2% acidity and minor defects. Plain “olive oil” or “pure” olive oil is refined oil — chemically or thermally treated to strip out defects, and therefore also stripped of polyphenols and flavour — blended with a little virgin oil for taste. Olive pomace oil is solvent-extracted from the leftover paste. The persistent claim that extra virgin olive oil is unsuitable for cooking because of a low smoke point does not hold up well. Its smoke point is around 190–210 °C, above normal pan-frying and roasting temperatures, and its high monounsaturated content and polyphenols make it more oxidatively stable in real cooking tests than many seed oils with higher smoke points. What it is genuinely bad for is prolonged deep-frying, where the cost is the argument as much as the chemistry. Light and heat degrade it. Buy in dark glass or tin, keep it away from the hob, and use it within a few months of opening — the peppery catch at the back of the throat that marks a good fresh oil is oleocanthal, and it fades as the oil ages. Olive oil is 100% fat and 884 kcal per 100 g, like every pure oil. What distinguishes it is the composition: 13.81 g of saturated fat per 100 g, the rest predominantly monounsaturated oleic acid. This page's panel shows Vitamin E at 5.1 mg (about 128% of the adult reference intake) and Vitamin K at 57.5 µg (82%) per 100 g — though at a tablespoon per serving, those are around a tenth of the figures shown. The health interest is largely in the polyphenols, which are present in extra virgin oil and largely absent from refined. An EU-authorised health claim permits olive oil polyphenols to be linked to protection of blood lipids from oxidative stress, at 5 mg of hydroxytyrosol and derivatives per 20 g of oil — a threshold many supermarket oils do not meet and few declare. Source: CoFID 2021 (McCance and Widdowson, UK), code 17-038 (matched record: "Oil, olive"). N = present but not quantified; Tr = trace; not measured = no value in the source. These figures are the amount in the food. How much the body absorbs can vary, see each nutrient's entry for detail.Olive Oil in more detail
Nutrients worth knowing about
Other oils
Micronutrients (per 100g, as-eaten)
Nutrient Amount % adult reference intake Minerals Iron 0.4 mg 3% Calcium Tr (trace) . Magnesium Tr (trace) . Potassium Tr (trace) . Sodium Tr (trace) . Chloride Tr (trace) . Phosphorus Tr (trace) . Zinc Tr (trace) . Copper 0.01 mg 1% Manganese Tr (trace) . Iodine Tr (trace) . Selenium Tr (trace) . Vitamins Vitamin A N (present, not quantified) . Vitamin C 0 mg 0% Vitamin D 0 ug 0% Vitamin E 5.1 mg 128% Vitamin K 57.5 ug 82% Vitamin B1 (thiamin) Tr (trace) . Vitamin B2 (riboflavin) Tr (trace) . Vitamin B3 (niacin) Tr (trace) . Vitamin B5 (pantothenic acid) Tr (trace) . Vitamin B6 Tr (trace) . Vitamin B7 (biotin) Tr (trace) . Vitamin B9 (folate) Tr (trace) . Vitamin B12 0 ug 0% What this food is a source of