Olive oil is one of the most well-supported heart-healthy foods in nutrition research. People who consume more than half a tablespoon per day have a 14% lower risk of cardiovascular disease and an 18% lower risk of coronary heart disease compared to people who rarely use it, based on large U.S. cohort data published in the Journal of the American College of Cardiology. The benefits come from a combination of its fat profile, its antioxidant compounds, and what it replaces in your diet.
Why Olive Oil Benefits the Heart
Olive oil is primarily made up of monounsaturated fatty acids. When these fats replace saturated fats in your diet, they help improve blood cholesterol levels and reduce cardiovascular risk. But the fat composition alone doesn’t explain the full picture. Extra virgin olive oil is also rich in polyphenols, a class of plant-based antioxidants that protect cells from oxidative damage and reduce inflammation in blood vessels.
These polyphenols appear to work partly by improving how your blood vessels function. A study in the American Journal of Hypertension found that young women with mild high blood pressure who consumed polyphenol-rich olive oil saw their systolic blood pressure drop by about 8 points and diastolic pressure drop by nearly 7 points. The mechanism: the polyphenols increased the availability of nitric oxide, a molecule that relaxes and widens blood vessels. More flexible blood vessels mean lower blood pressure and less strain on the heart over time.
The PREDIMED Trial: A Landmark Finding
The strongest evidence comes from the PREDIMED trial, a large randomized study that tested a Mediterranean diet supplemented with extra virgin olive oil against a control diet. Both the original and republished analysis found that the Mediterranean diet groups reduced their incidence of major cardiovascular events by approximately 30%. That’s a striking number for a dietary intervention, and it placed olive oil at the center of heart-healthy eating recommendations worldwide.
What About Cholesterol?
Here’s where the story gets more nuanced. A meta-analysis of 34 randomized controlled trials found that olive oil consumption, on its own, has minimal direct effects on LDL (“bad”) cholesterol, HDL (“good”) cholesterol, or triglyceride levels. Each additional 10 grams per day barely moved the numbers. HDL showed a small bump at around 20 grams per day (roughly 1.5 tablespoons), but the change was modest.
This doesn’t mean olive oil isn’t helping your heart. It suggests the benefits operate through other pathways: reducing inflammation, improving blood vessel function, protecting LDL particles from oxidative damage (which is what makes them dangerous in the first place), and lowering blood pressure. Focusing only on cholesterol numbers misses most of what olive oil does.
How Much You Need
The cardiovascular benefits in the largest U.S. study kicked in at more than half a tablespoon per day, which is roughly 7 grams. That’s not a lot. Drizzling olive oil on a salad or using it to sauté vegetables easily gets you there. Simply replacing 5 grams per day of butter, margarine, or mayonnaise with olive oil was associated with a 5% to 7% lower risk of cardiovascular disease and coronary heart disease.
The American Heart Association includes olive oil among its recommended liquid plant oils as part of heart-healthy dietary patterns, alongside soybean and canola oils. The guidance is straightforward: use nontropical plant oils in place of animal fats and tropical oils like coconut or palm oil during food preparation.
Olive Oil and Weight
Weight gain is itself a cardiovascular risk factor, so how olive oil affects body weight matters. Data from three large U.S. cohorts found that each additional half-tablespoon of olive oil per day was associated with slight but consistent weight loss over time. Other added fats told a different story: increases in butter, margarine, and other vegetable oils were all linked to weight gain. Substituting olive oil for those fats was associated with less long-term weight gain in middle-aged adults. The reasons likely involve a combination of satiety, the metabolic effects of monounsaturated fats, and the foods that olive oil tends to accompany (vegetables, salads, whole grains).
Extra Virgin vs. Refined Olive Oil
Not all olive oil delivers the same benefits. Extra virgin olive oil is mechanically extracted without chemicals, preserving its polyphenols, vitamins, and other natural compounds. Refined olive oil goes through processing that strips away most of these antioxidants. Since polyphenols drive many of the cardiovascular benefits, including the blood pressure and blood vessel improvements, extra virgin is the better choice for heart health.
Refined olive oil still contains the same monounsaturated fats, so it’s not without value. But if you’re choosing olive oil specifically for its heart-protective properties, the extra virgin version is meaningfully superior.
Cooking With Olive Oil
A common concern is that heat destroys olive oil’s beneficial compounds. Extra virgin olive oil has a smoke point of about 410°F, which is well above typical sautéing and roasting temperatures. Testing has shown that even when heated above 350°F for 36 hours straight, extra virgin olive oil maintains most of its nutritional properties and resists oxidation. The high monounsaturated fat content and the antioxidant polyphenols themselves act as a built-in defense against heat degradation. So cooking with it is fine, and you don’t need to reserve it only for cold uses like salad dressings.
That said, using it unheated preserves the maximum polyphenol content. A practical approach is to cook with it when you need a cooking fat and also drizzle it raw over finished dishes, vegetables, or bread to get the full spectrum of benefits.