By R.Davies, PhD・Nutrition
Updated January 19, 2026 | 5 min read
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.
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, the 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 really just refined fats), EVOO provides a combination of healthy fatty acids and 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.
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Olive oil is composed primarily (around 75%) of oleic acid, a monounsaturated fatty acid ('MUFA'). Unlike saturated fats, which tend to raise LDL ("bad") cholesterol, or highly processed polyunsaturated oils ('PUFA'), oleic acid has neutral-to-beneficial effects on your blood lipid profile.
Replacing saturated fats with olive oil tends to improve cholesterol ratios without lowering the "good" HDL cholesterol [1]. However, the cardiovascular benefits of olive oil extend far beyond its fatty acid profile.
The most distinctive compounds in EVOO are 'polyphenols'. These are plant compounds ("phytonutrients") that have antioxidant and anti-inflammatory properties. The main polyphenols include: hydroxytyrosol, tyrosol, oleuropein, oleocanthal, and oleacein.
Polyphenol content varies significantly between different types of olive oil. EVOO contains around 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” (which is damage from free radicals to your cells) and help control inflammation. Studies have shown that the high-polyphenol olive oil reduces markers of oxidation and inflammation more effectively than low-polyphenol versions, even when the fat composition of the oil was the same [2].
The cardiovascular benefits of EVOO are proven. Researchers found that those consuming the most olive oil lowered their risk of cardiovascular disease by over a third. For every 10 grams a day increase in EVOO per day, cardiovascular disease risk was reduced by 10% [3].
A landmark study in people with high cardiovascular disease 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 [4]. The olive oil group received about one litre per week to use freely in their household.
Similar results have also 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 [5].
The polyphenols in EVOO lower LDL cholesterol oxidation, which is a key step in the development of atherosclerosis ('blocked arteries': a precursor to cardiovascular diseases). They also improve “endothelial function” (the ability of blood vessels to relax and dilate properly, and control blood pressure), and they reduce inflammation as well.
The compound 'oleocanthal' has anti-inflammatory effects similar to ibuprofen, though at much lower potency [6]. Regular consumption provides a gentle, ongoing anti-inflammatory effect that may contribute to reduced disease risk, healthy ageing and other diseases caused by inflammation.
Beyond cardiovascular health, olive oil also provides vitamin E, which has been associated with better cognitive function in older adults, lower risk of depression, and improved blood sugar control [7]. Some research suggests protective effects against certain cancers, though the evidence is not as strong.
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.
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 it contains a lot of calories.
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 fat intake.
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.
For maximum health benefits, choose EVOO. Sure, it will cost more than the refined olive oils, but the polyphenol content justifies the price. Have a look at how much some of those 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, it 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 its polyphenol content.
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 vegetables. 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.
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.
1. Baggio G et al. Olive-oil-enriched diet: effect on serum lipoprotein levels and biliary cholesterol saturation. Am J Clin Nutr. 1988 Jun;47(6):960-4. PMID: 3132035
2. Vidal Damasceno J et al. Effects of daily extra virgin olive oil consumption on biomarkers of inflammation and oxidative stress: a systematic review and meta-analysis. Crit Rev Food Sci Nutr. 2026;66(2):392-408. PMID: 40749711
3. Guasch-Ferré M et al. Olive oil intake and risk of cardiovascular disease and mortality in the PREDIMED Study. BMC Med. 2014 May 13;12:78. PMID: 24886626
4. Estruch R et al. PREDIMED Study Investigators. Primary Prevention of Cardiovascular Disease with a Mediterranean Diet Supplemented with Extra-Virgin Olive Oil or Nuts. N Engl J Med. 2018 Jun 21;378(25):e34. PMID: 29897866
5. Guasch-Ferré M et al. Consumption of Olive Oil and Risk of Total and Cause-Specific Mortality Among U.S. Adults. J Am Coll Cardiol. 2022 Jan 18;79(2):101-112. doi: 10.1016/j.jacc.2021.10.041. PMID: 35027106
6. Beauchamp GK et al. Phytochemistry: ibuprofen-like activity in extra-virgin olive oil. Nature. 2005 Sep 1;437(7055):45-6. PMID: 16136122
7. Lee ARYB et al. Vitamin E, Alpha-Tocopherol, and Its Effects on Depression and Anxiety: A Systematic Review and Meta-Analysis. Nutrients. 2022 Feb 3;14(3):656. PMID: 35277015
Published: January 19, 2025
Lead Author: R.Davies, PhD | Author Bio
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