Olive Oil's Health Benefits Questioned, With Alternatives Proposed

While often lauded as a cornerstone of the Mediterranean diet and a heart-healthy elixir, olive oil's reputation is being re-examined, with concerns raised about its calorie content and potential to contribute to weight gain. Nutritionist Rob Hobson, author of The Low Appetite Cookbook, suggests that the way olive oil is frequently used—drizzled liberally over foods—can lead to an unintended calorie surplus, despite its beneficial monounsaturated fats.

Research from Kyoto University in Japan has indicated that consuming a small amount of olive oil before carbohydrates may help reduce blood sugar spikes, potentially aiding in the prevention of type 2 diabetes. This effect is partly attributed to increased levels of GLP-1, a hormone that acts as a natural appetite suppressant, similar to those found in popular weight-loss injections.

However, gram for gram, olive oil is more calorific than butter. One tablespoon contains approximately 120 calories and 14g of fat, compared to butter's 100 calories and 11g of fat. While olive oil contains less saturated fat (2g per tablespoon versus 7g in butter), its high overall fat content means it's easy to consume excess calories without realizing it.

"The main fat in olive oil is oleic acid, which is what's known as a monounsaturated fat," explained Hobson. "It also contains smaller amounts of a type called polyunsaturated fats, mainly linoleic acid, which is an omega-6 fat. Both monounsaturated and polyunsaturated fats are beneficial for heart health, particularly when they replace saturated fats." These fats help remove LDL cholesterol from blood vessels, thus reducing heart disease risk. Olive oil also contains polyphenols, plant compounds with antioxidant properties that protect cells from damage.

A 2022 meta-analysis of 36 studies published in the Journal of Clinical Nutrition suggested that consuming about 25g (nearly two tablespoons) of olive oil daily was associated with lower risks of cardiovascular disease, type 2 diabetes, and all-cause mortality. However, scientists caution that these findings are observational and may not account for all contributing factors.

Hobson emphasizes that the benefit of olive oil lies in swapping it for other fats, such as butter or margarine, rather than simply adding it to the diet. "Just because something is good for us doesn't mean we need unlimited amounts of it," he stated. Unlike nuts or avocados, oil lacks fiber and other components that promote satiety, potentially leading to increased calorie intake.

Extra-virgin olive oil, produced from the first pressing of olives, generally contains higher levels of vitamins and health-promoting compounds like polyphenols compared to standard olive oil. A 2018 study involving heart patients found that those on Mediterranean diets supplemented with extra-virgin olive oil or nuts had fewer major cardiovascular events than those on a reduced-fat diet. Subsequent analysis indicated a stronger association between higher extra-virgin olive oil consumption and lower cardiovascular risk.

For those seeking alternatives, rapeseed oil is highlighted as having similar health properties. It is rich in monounsaturated fats, contains omega-3 fats, and has about half the saturated fat of olive oil, though with slightly lower levels of monounsaturated fats and polyphenols. Sesame oil also offers healthy monounsaturated fats and unique antioxidants like sesamin and sesamol. Coconut oil, however, is advised to be consumed sparingly due to its high saturated fat content.

When cooking at high temperatures, rapeseed oil or sesame oil may be preferable to olive oil due to their higher smoke points, according to Professor Duane Mellor, a registered dietitian and researcher at Aston University. He also advises using a measuring spoon for olive oil to control portion sizes, suggesting a limit of one to two tablespoons per meal.