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.