Taking a tablespoon of olive oil daily is a well-supported health habit, and the FDA has even issued a qualified health claim for it. The agency’s guidance specifically states that about 1½ tablespoons (20 grams) per day, when used to replace fats higher in saturated fat, may reduce the risk of coronary heart disease. The key caveat: it should replace other fats in your diet, not simply add calories on top of what you already eat.
What’s in a Tablespoon
One tablespoon of extra virgin olive oil contains about 126 calories and 14 grams of fat, nearly all of it monounsaturated. You also get roughly 19% of your daily vitamin E and a small amount of vitamin K. But the most interesting components are the plant compounds called polyphenols, which act as antioxidants and have anti-inflammatory effects throughout the body. These are what set extra virgin olive oil apart from refined versions, which lose most of these compounds during processing.
The Heart Health Evidence
The strongest case for daily olive oil comes from cardiovascular research. The PREDIMED trial, one of the largest and most cited nutrition studies ever conducted, found that people following a Mediterranean diet supplemented with extra virgin olive oil had approximately 30% fewer major cardiovascular events (heart attacks, strokes, and cardiovascular deaths) compared to a control group. That’s a substantial reduction, on par with what some medications achieve.
The benefit appears to come from multiple mechanisms working together. The monounsaturated fat in olive oil helps improve your ratio of HDL to LDL cholesterol. The polyphenols reduce oxidative stress on blood vessel walls. And oleic acid, the primary fat in olive oil, appears to lower inflammation markers that contribute to plaque buildup in arteries. These effects compound over time, which is why consistent daily use matters more than occasional large doses.
Effects on Appetite and Weight
Adding pure fat to your diet sounds like it should cause weight gain, but olive oil has an interesting relationship with hunger hormones. Unsaturated fats like those in olive oil are better at stimulating GLP-1 release than saturated fats like butter. GLP-1 is a hormone that signals fullness to your brain and slows stomach emptying, which is the same hormone targeted by medications like semaglutide. In human studies, a Mediterranean diet rich in olive oil led to higher post-meal GLP-1 levels, improved insulin sensitivity, and lower blood sugar compared to a diet high in saturated fats.
This doesn’t mean olive oil is a weight loss tool on its own. At 126 calories per tablespoon, it adds up quickly if you’re pouring freely. The benefit comes from using it as a swap: drizzling olive oil on bread instead of butter, using it as a salad dressing base instead of creamy alternatives, or cooking with it instead of other oils. When it replaces less healthy fats rather than adding to your total intake, the calorie math stays neutral while the metabolic effects tilt positive.
Drinking It Straight vs. Using It in Food
Some people take olive oil as a “shot” on an empty stomach, often first thing in the morning. There’s no evidence this timing provides special benefits compared to using olive oil with meals. What it can do is act as a mild laxative. The fat smooths the lining of the bowel and helps stools retain water, making them softer and easier to pass. If you’re prone to loose stools or digestive sensitivity, taking a full tablespoon on an empty stomach may cause cramping or urgency.
Using olive oil as part of a meal is more practical for most people and may actually improve nutrient absorption. Fat-soluble vitamins (A, D, E, and K) and certain antioxidants in vegetables are better absorbed when eaten with fat. A drizzle of olive oil on a salad or roasted vegetables serves double duty: you get the benefits of the oil itself plus better uptake of nutrients from the food it accompanies.
Storage Matters More Than You Think
The polyphenols that make extra virgin olive oil valuable are surprisingly fragile. Research published in the Journal of Agricultural and Food Chemistry tracked how these compounds break down over time at different temperatures. At room temperature (about 25°C or 77°F), key antioxidant compounds dropped to 52-63% of their original levels after just six months in opened bottles. At cooler temperatures around 15°C (59°F), those same compounds held at 62-73% after a full year.
Heat accelerates the loss dramatically. Oil stored at 50°C (122°F), which isn’t hard to reach near a stove, lost over 70% of certain antioxidants within three months. The practical takeaway: store your olive oil in a cool, dark place with the cap tightly closed, and use it within a few months of opening. Buying smaller bottles more frequently preserves more of what you’re paying for. A dark glass bottle or tin protects better than clear glass.
Which Type of Olive Oil to Choose
Extra virgin olive oil is the only type worth taking for health purposes. It’s made from the first mechanical pressing of olives without chemical processing, which preserves the polyphenols and other bioactive compounds. “Pure” or “light” olive oil has been refined, stripping out most of the antioxidants while retaining the fat profile. You still get the monounsaturated fat benefits from refined olive oil, but you lose the anti-inflammatory compounds that drive many of the health outcomes seen in clinical trials.
Look for a harvest date on the bottle rather than just a “best by” date. Fresher oil contains more polyphenols. Oil from the current or most recent harvest season will deliver more of the compounds that make daily consumption worthwhile. A peppery or slightly bitter taste when you try it straight is actually a sign of high polyphenol content, not a flaw.