Olive oil has been produced and used across the Mediterranean for over four thousand years, and few foods carry as much cultural and religious weight in that history — olive oil anointed kings and athletes in ancient Greece, fueled sacred lamps in temples across multiple religious traditions, and was valued highly enough in ancient trade to function as a form of currency and diplomatic gift between civilizations.
Beyond its practical uses, olive oil became deeply embedded in Mediterranean identity and cuisine, and modern nutritional science eventually turned rigorous attention specifically to the traditional "Mediterranean diet" — of which olive oil is a defining component — as a subject of some of the largest and longest-running nutritional research in history. Its scientific reputation today rests on some of the most extensive epidemiological evidence available for any single food.
Olive oil has an exceptionally large body of evidence behind it, built primarily from massive long-term population studies rather than short clinical trials. A 2022 meta-analysis of 13 prospective cohort studies found higher olive oil consumption was associated with significantly reduced risk of both cardiovascular disease (15% lower risk) and all-cause mortality (17% lower risk), with a clear dose-response relationship — more olive oil, more benefit, up to a point. A separate, even larger outcome-wide meta-analysis pooled data from over 800,000 participants for cardiovascular outcomes and over 1.2 million for cancer outcomes, finding consistent risk reductions for cardiovascular disease and all-cause mortality specifically.
The honest caveat that applies to nearly all nutrition research at this scale: this evidence comes primarily from observational cohort studies rather than randomized controlled trials, meaning it shows strong, consistent association rather than the same type of proof an RCT provides — people who eat more olive oil tend to have other different lifestyle and dietary patterns too, which researchers work to statistically account for but can't fully eliminate. Given that caveat, the sheer scale (millions of participants), consistency across many independently-conducted studies, and clear dose-response pattern are what earn olive oil a "Strong" rating despite the observational nature of most of the evidence.
Cold-pressed from ripe or unripe olives; used raw as a finishing oil, for cooking, and historically for skin and hair care as well as food.