People drink olive oil, usually a tablespoon or two of extra-virgin, because it delivers a concentrated dose of protective plant compounds and healthy fats linked to lower heart disease risk, reduced inflammation, and better blood sugar control. The practice is common in Mediterranean countries, where average daily intake runs about 40 grams (roughly 3 tablespoons), and it has gained popularity elsewhere as research continues to connect olive oil with measurable health benefits.
Heart Protection and Cholesterol
The central reason olive oil shows up in cardiovascular research is its effect on LDL cholesterol, the type that drives plaque buildup in arteries. LDL itself isn’t the whole problem. The real danger comes when LDL particles become oxidized, which triggers an inflammatory chain reaction in blood vessel walls. Extra-virgin olive oil is rich in antioxidant compounds that make LDL particles more resistant to this oxidation. In one study of men with vascular disease, those who consumed extra-virgin olive oil (with roughly 800 mg/kg of phenolic compounds) had significantly less LDL oxidation than those consuming refined olive oil, which contained only 60 mg/kg of the same compounds. Their immune cells also absorbed less of the damaged cholesterol, a sign that the early steps of artery clogging were being disrupted.
The landmark PREDIMED trial found that people eating a Mediterranean diet supplemented with extra-virgin olive oil reduced their risk of major cardiovascular events by 31% compared to those on a control diet. That trial used about 40 grams of olive oil per day, which is roughly 3 tablespoons. Drinking olive oil is one straightforward way to hit that amount, especially if your cooking alone doesn’t get you there.
A Natural Anti-Inflammatory Compound
If you’ve ever noticed a peppery sting at the back of your throat when swallowing good olive oil, that sensation comes from oleocanthal, a compound that works remarkably like ibuprofen. Oleocanthal blocks the same two inflammation-driving enzymes (COX-1 and COX-2) that ibuprofen targets, and it does so more potently at equal concentrations. At the same molecular dose, oleocanthal inhibits 41% to 57% of COX enzyme activity compared to ibuprofen’s 13% to 18%.
That doesn’t mean a shot of olive oil replaces a pain reliever for a headache. The amount of oleocanthal in a few tablespoons is modest. But consumed daily over months and years, this low-level anti-inflammatory effect adds up. Chronic, low-grade inflammation is a driver behind heart disease, type 2 diabetes, and neurodegenerative conditions, so even a small daily reduction matters over time.
Blood Sugar and Insulin Sensitivity
Olive oil appears to help the body handle sugar more effectively. In animal studies of diet-induced diabetes, adding extra-virgin olive oil to a high-fat diet significantly improved fasting blood sugar levels, glucose tolerance, and insulin sensitivity compared to the same diet without it. The oil also improved pancreatic beta-cell function, meaning the cells responsible for producing insulin worked better.
Some people drink olive oil before meals specifically to blunt the blood sugar spike that follows eating. Fat slows stomach emptying, which means glucose from your meal enters the bloodstream more gradually. Extra-virgin olive oil also slowed gastric emptying more than a control in research measuring stomach retention rates, with significant increases within 30 minutes of consumption. This slower digestion can translate to a gentler rise and fall in blood sugar after eating.
Gut Health and the Microbiome
The phenolic compounds in olive oil act as a kind of fertilizer for beneficial gut bacteria. Research shows these compounds increase populations of bacterial groups associated with healthy metabolic markers, including Bifidobacteria, Lactobacillus, and Akkermansia. That last one is particularly notable: Akkermansia muciniphila is inversely associated with obesity, diabetes, and inflammation, and compounds found in virgin olive oil have been shown to dramatically increase its proportion in animal models of inflammatory bowel disease.
Beyond feeding good bacteria, olive oil’s phenolic compounds help maintain the physical barrier of the intestinal wall. They upregulate the genes responsible for keeping tight junctions between intestinal cells sealed, which prevents unwanted molecules from leaking into the bloodstream. In obese mice, one of olive oil’s key antioxidants increased the expression of these tight-junction proteins while also reducing markers of inflammation in the liver. A “leaky gut” is increasingly recognized as a contributor to systemic inflammation, so this barrier-strengthening effect has implications well beyond digestion.
Brain Health
Oleocanthal, the same compound behind olive oil’s anti-inflammatory properties, also shows promise for brain health. In both cell and animal studies, oleocanthal enhanced the brain’s ability to clear amyloid-beta proteins, the sticky plaques that accumulate in Alzheimer’s disease. It did this by boosting the activity of two key transport proteins at the blood-brain barrier, increasing the clearance rate of amyloid from 62% in control mice to nearly 80% in treated mice. It also increased the expression of an enzyme that breaks down amyloid within the brain itself by 1.6 times.
These are animal and lab findings, not proof that drinking olive oil prevents dementia. But they offer a biological explanation for the consistent epidemiological observation that populations eating Mediterranean diets, rich in olive oil, tend to have lower rates of cognitive decline.
Appetite and Weight
Drinking olive oil might seem counterintuitive for weight management since it’s calorie-dense at about 120 calories per tablespoon. But extra-virgin olive oil increased gastric retention in research, meaning food stayed in the stomach longer, which reduced hunger signals. In animal studies, olive oil reduced overall food intake through mechanisms acting on the gastrointestinal tract rather than through the hormonal appetite signals researchers expected. The net effect may be that a tablespoon of olive oil before a meal leads you to eat less of everything else.
How Much and What Kind
The European Food Safety Authority allows olive oil to carry a health claim for protecting LDL from oxidation, but only if it provides at least 5 mg of hydroxytyrosol and related compounds per 20 grams of oil (about 1.5 tablespoons). That’s a daily intake of roughly 1.5 tablespoons of high-quality extra-virgin olive oil. The PREDIMED trial used about 3 tablespoons daily, and average intake in Mediterranean countries sits around that level.
For most people, 1 to 3 tablespoons per day is a reasonable range. You can drink it straight, mix it into a smoothie, or simply use it generously on food. The key distinction is quality: extra-virgin olive oil contains dramatically more protective compounds than refined versions. That peppery, slightly bitter taste is actually a marker of high phenolic content, so if your olive oil tastes like nothing, it’s probably doing less for you.
Potential Downsides
Olive oil is generally well tolerated. A small number of people experience nausea when drinking it on an empty stomach, particularly if they’re not used to consuming fat that way. It can also have a mild laxative effect, which is actually considered a benefit for people dealing with constipation but can be unwelcome if you weren’t expecting it. Starting with a teaspoon and working up to a full tablespoon lets your digestive system adjust. The calorie load is the most practical concern: 3 tablespoons adds about 360 calories to your day, so it works best when it replaces other fats rather than being added on top of your usual diet.