Health benefits of olive oil

Olive oil is a plant-based fat known for its beneficial effects on cardiovascular and metabolic health. This article reviews the main health benefits of olive oil, including its role in the Mediterranean diet.

This article is from the Mediterranean Diet & Nutrition sections of our Library.

Olive oil is a plant-based fat extracted from olives, the fruit of the olive tree. It comes in a few different “grades”: extra virgin olive oil (EVOO), virgin olive oil, and refined olive oil. The difference between the grades relates to the processing method used to extract the oil, acidity level, and — most importantly — its polyphenol content.

EVOO is the least processed and contains the highest levels of beneficial compounds. Unlike most other cooking oils, which are primarily just refined fats, EVOO provides a combination of healthy fatty acids and potent antioxidants. This unique combination is what sets it apart (nutritionally) from other fats. It also tastes great.

While olive oil has been a dietary staple in Mediterranean countries for thousands of years, the scientific evidence for its health benefits has only emerged over the past few decades, with particularly strong findings in the last few decades.

What are the benefits of eating olive oil?

Monounsaturated Fats

Olive oil is composed primarily (around 75%) of oleic acid, a monounsaturated fatty acid (MUFA). Unlike saturated fats, which tend to raise LDL cholesterol, or highly processed polyunsaturated oils (PUFAs), oleic acid has neutral-to-beneficial effects on your blood lipid levels.

Replacing saturated fats with olive oil in the diet tends to improve cholesterol ratios without lowering beneficial HDL cholesterol. However, the cardiovascular benefits of olive oil extend beyond its fatty acid profile.

Polyphenols

The most distinctive compounds in EVOO are polyphenols — plant compounds with potent antioxidant and anti-inflammatory properties.

The main polyphenols include: hydroxytyrosol, tyrosol, oleuropein, oleocanthal, and oleacein.

Polyphenol content varies significantly between olive oil types. EVOO contains 100-500 mg per kg, while refined olive oils contain almost none. So not all olive oils are equal when it comes to their health benefits. Processing, storage time, and heat can all reduce polyphenol levels as well.

So, why are polyphenols so good for health? They reduce “oxidative stress” (damage from free radicals to your cells) and control inflammatory pathways.

Studies have shown that the high-polyphenol olive oil reduced markers of oxidation and inflammation more effectively than low-polyphenol versions, even when fat composition was identical.

Is olive oil good for you?

The cardiovascular benefits of EVOO are well supported by extensive research. found that those consuming the most olive oil lowered the risk of cardiovascular disease by over a third. For every 10-gram-a-day increase in EVOO, cardiovascular disease risk was reduced by 10%.

A landmark study, involving 7,447 participants at high cardiovascular risk, found that a Mediterranean diet supplemented with EVOO reduced major cardiovascular events (heart attack, stroke, or cardiovascular death) by around a third compared to a control diet over five years.

The olive oil group received about one litre per week to use freely in their household.

Similar results have been shown for reducing type 2 diabetes, cancer risk, respiratory disease risk, and improving brain health.

Researchers reported that replacing 10 grams a day of margarine, butter, mayonnaise and/or other dairy fats with 10 grams of olive oil reduced all-cause mortality.

How?

The polyphenols in EVOO reduce LDL cholesterol oxidation, a key step in the development of atherosclerosis.

They also improve “endothelial function” (the ability of blood vessels to relax and dilate properly, and control blood pressure) and they reduce inflammation.

The compound oleocanthal has anti-inflammatory effects similar to ibuprofen, though at much lower potency.

Regular consumption provides a gentle, ongoing anti-inflammatory effect that may contribute to reduced chronic disease risk, healthy ageing and other inflammatory-related diseases.

Additional Benefits

Beyond cardiovascular health, olive oil also provides vitamin E and has been associated with better cognitive function in older adults, lower risk of depression, and improved blood sugar control.

Some research suggests protective effects against certain cancers, though evidence is more limited.

A tablespoon (15ml) of olive oil provides about 120 calories, 14g of fat (mostly monounsaturated), 2mg of vitamin E (13% of daily needs), and varying amounts of polyphenols depending on quality.

Is a spoonful of olive oil a day good for you?

The evidence suggests that 15-30g per day (1-2 tablespoons) provides meaningful health benefits. This aligns with typical Mediterranean dietary patterns, where olive oil is the primary added fat.

Higher intakes aren't necessarily better, as calorie density does matter as well. Two tablespoons provide about 240 calories, which needs to be considered in your overall energy intake, if that is a priority.

The easiest, most effective benefit will come from replacing other fats (like butter, margarine, or refined oils) rather than simply adding olive oil on top of your current diet.

How to eat more olive oil?

1. Replace, Don't Add

The healthiest approach is to substitute olive oil for other fats rather than adding extra calories. Use EVOO instead of butter on bread, replace vegetable oil in cooking, and use it in place of cream-based salad dressings.

Make a simple vinaigrette by mixing three parts olive oil with one part vinegar (balsamic, red wine, or apple cider) with a touch of mustard and seasoning of your choice. This becomes your default salad dressing and can be stored in a jar for weeks.

2. Prioritise Extra Virgin

For maximum health benefits, choose EVOO. Sure, it will cost more than refined olive oils, but the polyphenol content justifies the price. Have a look at how much some antioxidant supplements are sold for!

For cooking, EVOO works well for most purposes — it's more stable than commonly believed, with a smoke point of 190-210°C, which is suitable for most home cooking.

Use cheaper refined olive oil only for very high-heat cooking if needed, and reserve your best EVOO for drizzling on finished dishes, where its flavour and compounds remain intact. Store olive oil in a dark bottle away from heat and light to preserve polyphenols.

3. Make It a Habit

Build olive oil into your routine rather than thinking of it as optional. Drizzle it over vegetables before roasting — this enhances both flavour and the absorption of fat-soluble vitamins in the veg. Add a tablespoon to soups or stews just before serving.

Use it to sauté garlic and onions at the start of almost any savoury dish. Keep a small bottle on the table for drizzling over finished meals. The Mediterranean approach treats olive oil as a condiment as much as a cooking fat — use it generously and visibly.

Bottom Line

Olive oil, particularly EVOO, is supported by some of the strongest evidence available. Its unique combination of monounsaturated fats and polyphenols provides measurable cardiovascular, metabolic, and potentially brain health.

Replacing other fats with 1–2 tablespoons of EVOO daily is a simple, evidence-based dietary change. It's one of the few foods where decades of research, from large trials to small focused studies, consistently point in the same direction.