Olive Oil Benefits: What Does the Science Actually Show?

Olive oil is often held up as one of the best fats you can eat. But that raises an obvious question: if it's basically pure fat, and a fairly calorie-dense one at that, what makes it so special? Are its health benefits actually backed by science, or are some of the claims about it just well-worn myths?

What sets olive oil apart isn't just its fatty acid makeup, but also the bioactive compounds found in the extra virgin product. Most research has focused on its effects on heart and cardiovascular health, while the effects of its polyphenols on specific health markers have been studied separately.

So it's worth putting the bold promises aside and looking at what the science actually says about olive oil — and how to put that knowledge into practice day to day.

The main fatty acid in olive oil is oleic acid – a monounsaturated fatty acid that makes up most of its fat content. Besides oleic acid, the oil also contains tocopherols (vitamin E), polyphenols, phytosterols, and other compounds naturally found in olives.

Extra virgin olive oil stands out because it's obtained from olives using mechanical and other physical processes, without chemical refining. This preserves the compounds naturally present in olives, especially the polyphenols. Scientific reviews show that the amount and composition of polyphenols can depend on the olive variety, fruit ripeness, extraction process and conditions.

Polyphenols are natural phenolic compounds found in olives and their oil. In extra virgin olive oil, they make up an important part of its bioactive compounds, which is why researchers look not just at olive oil's fatty acids, but at the biological activity of these compounds too. Most research has focused on their links to oxidative stress and certain cardiovascular disease risk markers.

A systematic review and meta-analysis of randomized controlled trials showed that olive oil with a higher polyphenol content was associated with lower levels of oxidized LDL, although not all of the oxidative stress markers assessed showed significant changes. There is not yet enough data on how these compounds affect the risk of specific diseases, so their health benefits should be assessed with caution.

It's also worth noting that polyphenol content varies between different olive oils. The EU-authorized health claim about olive oil polyphenols protecting blood lipids from oxidative stress can only be used when 20 g of the oil provides at least 5 mg of hydroxytyrosol and its derivatives. So this effect cannot automatically be attributed to every Extra Virgin olive oil.

When it comes to heart and cardiovascular health, it's not just how much fat you eat that matters, but what type. Olive oil is dominated by monounsaturated oleic acid, and when weighing its place in your diet, it's worth considering what other fats it's replacing.

One large clinical trial, involving 7,447 people at higher risk of cardiovascular disease, compared a Mediterranean diet supplemented with extra virgin olive oil or nuts against a control lower-fat diet. After a median follow-up of 4.8 years, a re-analysis of the trial found a lower risk of major cardiovascular events in the extra virgin olive oil group: the hazard ratio was 0.69 (95% CI 0.53–0.91). This means the risk of major cardiovascular events in this group was roughly 31% lower than in the control group. It's important to stress, though, that this trial assessed the overall Mediterranean diet supplemented with extra virgin olive oil, not the effect of olive oil alone.

When it comes to cholesterol, what matters isn't just that you eat olive oil, but what it replaces in your diet.

Oleic acid is an unsaturated fatty acid, and replacing saturated fats with unsaturated fats helps maintain normal blood cholesterol levels. So in practice, it's more useful to think of olive oil's value not as a stand-alone "cholesterol-lowering" product, but as one of several unsaturated fat sources in your overall diet. For more on what to eat to lower cholesterol, and which foods are worth limiting when cholesterol is elevated, see our separate articles.

Olive oil's effect on lipid profile is also studied in clinical trials. A 2023 systematic review and meta-analysis, covering 10 randomized controlled trials, found that a higher olive oil polyphenol content was associated with a small reduction in LDL cholesterol, while the increase in HDL cholesterol was statistically significant.

That said, while these changes are meaningful for the lipid profile, they alone aren't enough to claim that olive oil by itself protects against heart disease. When assessing health benefits, it's important to consider not just cholesterol markers, but overall diet, physical activity, smoking, and other cardiovascular risk factors.

People discuss olive oil's potential benefit for joints because of the bioactive compounds it contains, but there isn't yet enough high-quality clinical data to say that olive oil itself directly improves joint health.

A 2026 systematic review and meta-analysis, evaluating olive-derived extracts and bioactive compounds in people with osteoarthritis or degenerative joint pain, found a small reduction in pain, but the review included only 6 studies, and the meta-analysis only 3 randomized controlled trials. The authors stress that the available evidence remains limited and preliminary.

Olive oil is also often mentioned in relation to digestion and gut function. Although there's considerably less research in this area than on cardiovascular health, some data suggests olive oil may help support healthier bowel movements.

For example, a 2025 double-blind randomized controlled trial involved 140 adults diagnosed with chronic constipation. For four weeks, they consumed either extra virgin or refined olive oil daily. Bowel movement indicators improved in both groups, but the extra virgin olive oil group saw a bigger improvement. Since this is a single clinical trial with a specific group of people, its results shouldn't be interpreted as proof that olive oil alone resolves constipation for everyone.

There's also growing interest in a possible link between extra virgin olive oil, its polyphenols, and the gut microbiota. A 2026 scientific review on olive oil and gut health discusses data on its possible effects on microbiota composition, the metabolites it produces, and gut barrier function. However, the authors stress that results from human studies are still inconsistent so far and depend on the type of olive oil, polyphenol content, overall diet, and the health status of study participants.

So it's still too early to claim that olive oil "improves the gut microbiota" or has a specific therapeutic effect on the digestive system. Still, the available data explain why its effect on the gut and digestive processes remains an active area of research.

Olive oil is a concentrated fat source, so its energy value is quite high: 100 g provides around 884 kcal. One tablespoon (about 13.5 g) provides roughly 119 kcal.

Not necessarily. What matters most is portion size and how much oil you have over the course of a day. Olive oil can be a great part of your daily diet, but it shouldn't be eaten without limit just because it's considered a healthy fat source.

There's no single amount of olive oil that suits everyone – it depends on your overall diet, other fats you eat, and your individual energy needs. Since olive oil is calorie-dense, it's important to consider not just its quality, but also portion size.

A 20 g portion of olive oil is sometimes mentioned, but this amount relates to the specific conditions for using the EU-authorized health claim about olive oil polyphenols. It's not a universal recommendation for everyone to eat exactly 20 g of oil every day.

You don't need to eat olive oil on its own or look for special ways to work it into your diet. The simplest approach is to use it in place of other fat sources in everyday dishes:

• salads – as the base of a dressing along with vinegar, lemon juice, or herbs;

• vegetables – to season fresh, roasted, or boiled vegetables;

• legume and grain dishes – stirred into beans, lentils, grains, or other dishes;

• fish – used as part of a sauce or marinade;

• in place of other fats – when cooking, you can replace butter or other fat sources with it.

The key isn't to pour as much oil as possible over your food, but to choose it as one of your main fat sources and pay attention to your total intake.

You'll find a selection of olive oils for everyday use in the OMEGAlab olive oil collection.

Yes, you can cook with olive oil. It can be used to prepare a wide range of everyday dishes, though it's worth considering the type of oil and cooking method you choose.

Olive oil is a fat- and calorie-containing product, but its value isn't determined by energy content alone. Olive oil's benefits are most closely tied to its place within the overall diet – especially when it replaces less healthy fat sources.

The strongest evidence relates to cardiovascular health and the Mediterranean diet pattern, while the effects of polyphenols on certain health markers remain an active area of research. Meanwhile, data on olive oil's direct benefit to joints is still limited. So olive oil should be viewed not as a "miracle" product, but as one of several healthy fat sources within a balanced diet.