Does olive oil protect your heart?

A large trial found fewer major heart events on a diet with extra virgin olive oil. Olive oil alone has not clearly lowered cholesterol or blood pressure.

Published October 2026

Short answer

Early, limited evidence: a Mediterranean diet with extra virgin olive oil cut major heart events in one large trial, but olive oil alone has not clearly lowered cholesterol or blood pressure. Evidence grade C (Limited). One large trial of a whole Mediterranean diet, withdrawn and re-analysed after protocol errors, plus observational cohorts; downgraded for indirectness and risk of bias.

Key takeaways

In a trial of 7,447 people at high heart risk, a Mediterranean diet with extra virgin olive oil had fewer major heart events than a low-fat diet over a median of 4.8 years [1].
Large observational studies link more olive oil with lower heart disease risk, about 16% for each extra 25 g a day, but they cannot prove cause [2].
Pooled trials of olive oil found no clear change in LDL or HDL cholesterol or in blood pressure [3] [4].
The largest trial was withdrawn and re-analysed after randomisation problems, so its headline numbers are less certain than they look [1].

The short version

Extra virgin Olive oil is linked to fewer heart problems in large studies, but the evidence is limited. The largest trial found fewer major heart events on a Mediterranean diet that included extra virgin olive oil than on a low-fat diet [1]. Olive oil alone has not clearly lowered cholesterol or blood pressure in pooled trials [3].

What the olive oil studies show

The largest trial is PREDIMED. It assigned 7,447 people at high heart risk, aged 55 to 80, to a Mediterranean diet with extra virgin olive oil, a Mediterranean diet with nuts, or a low-fat diet [1]. Over a median of 4.8 years, 96 people in the olive oil group had a major heart or stroke event, against 109 in the low-fat group. The adjusted hazard ratio was 0.69 (0.53 to 0.91), roughly a 31% lower rate of events [1].

Large observational studies point the same way. A 2022 meta-analysis of 24 cohort studies and three reports from one trial, covering more than 800,000 people, found about 16% lower heart disease risk for each extra 25 g of olive oil a day [2]. Within PREDIMED, the people who ate the most extra virgin olive oil, about 49 g a day on average, had about 25% lower risk of a wider set of heart events. That analysis used what people reported eating, not random assignment [5].

Trials of olive oil itself show little change in cholesterol or blood pressure. A 2024 meta-analysis of 33 randomised trials, with 2,020 people, found no significant effect on total, LDL or HDL cholesterol, triglycerides or blood pressure. It did find lower insulin levels and insulin resistance [3]. A 2024 meta-analysis of 17 trials, 14 on olive oil and 3 on flaxseed oil, also found no significant change in blood pressure [4].

Oil with more polyphenols may do more. A 2019 meta-analysis of 26 trials found high-polyphenol olive oil improved total and HDL cholesterol compared with low-polyphenol oil, with HDL up by about 2.4 mg/dL [6]. In a three-week crossover trial of 50 adults, high-polyphenol oil did not beat low-polyphenol oil on blood pressure, although systolic pressure fell by about 2.5 mmHg during the high-polyphenol period [7].

Other fats make a difference too. In a four-week trial of 94 adults, LDL cholesterol rose by about 0.38 mmol/L more on butter than on olive oil [8]. A 2023 meta-analysis of 13 trials found canola oil lowered LDL cholesterol more than olive oil, by about 6 mg/dL [9].

Observational data also link more olive oil with about 11% lower risk of death from any cause, and found no clear link with cancer [2].

The nuances

PREDIMED tested a whole diet, and olive oil was one part of it, so the trial cannot separate the oil's effect from the rest of the diet [1].

The trial has also been corrected. The original 2013 report was withdrawn in 2018 after protocol problems, including people enrolled without randomisation, and the authors published revised estimates [1]. A 2019 Cochrane review rated the evidence on cardiovascular death from this trial as low quality, with little or no effect (hazard ratio 0.81, 0.50 to 1.32). It rated the stroke reduction (hazard ratio 0.60) as moderate quality [10].

Observational studies cannot show cause and effect [2]. Results for heart disease also varied between the cohort studies, and the authors could not explain all of it [2].

Only two of the 30 trials in the Cochrane review reported adverse events, and those were absent or minor [10].

The trials cited here enrolled healthy adults or people at high heart risk, and none of them studied pregnancy [1] [7] [8].

Funding: the PREDIMED trial was funded by Spain's Instituto de Salud Carlos III, the Spanish Ministry of Health and others [1]. One author of the small blood pressure trial reported industry funding, including from Cobram Estate, an olive oil company [7].

What this means for you

If you already cook with olive oil, the trials do not show that using more of it will lower your cholesterol or blood pressure [3]. If you are choosing between fats, the one trial that compared olive oil with butter found butter raised LDL cholesterol more [8]. The heart evidence is strongest for a whole eating pattern: in Mediterranean-style diets, olive oil was the main cooking fat, with plenty of fruit, vegetables and legumes, more fish and less meat [10]. The highest intake in one study averaged about 49 g a day, roughly three and a half tablespoons [5].

Talk with a doctor before changing your diet, especially if you take medicines or have a heart condition.

Go deeper

Olive Oil — Extra virgin olive oil, eaten as part of a Mediterranean diet, is linked to fewer heart events, and a large trial of that diet found fewer major heart events.