If you Google "coconut oil," you'll see a slew of stories touting the alleged health benefits of this solid white fat, which is easy to find in supermarkets these days. But how can something that's chock-full of saturated fat — a known culprit in raising heart disease risk — be good for you?
Coconut does have some unique qualities that enthusiasts cite to explain its alleged health benefits. But the evidence to support those claims is very thin, says Dr. Qi Sun, assistant professor in the Department of Nutrition at the Harvard T.H. Chan School of Public Health.
"If you want to lower your risk of heart disease, coconut oil is not a good choice," he says. It's true that coconut oil tends to raise beneficial HDL cholesterol more than other fats do, possibly because coconut oil is rich in lauric acid, a fatty acid that the body processes slightly differently than it does other saturated fats.
Coconut oil's effect on cholesterol
But there's no evidence that consuming coconut oil can lower the risk of heart disease, according to an article in the April 2016 Nutrition Reviews. The study, titled "Coconut Oil Consumption and Cardiovascular Risk Factors in Humans," reviewed findings from 21 studies, most of which examined the effects of coconut oil or coconut products on cholesterol levels. Eight were clinical trials, in which volunteers consumed different types of fats, including coconut oil, butter, and unsaturated vegetable oils (such as olive, sunflower, safflower, and corn oil) for short periods of time. Compared with the unsaturated oils, coconut oil raised total, HDL, and LDL cholesterol levels, although not as much as butter did.
These findings jibe with results from a study by Dr. Sun and colleagues in the Nov. 23, 2016, issue of The BMJ, which examined the links between different types of saturated fatty acids and heart disease. Compared with other saturated fats (like palmitic acid, which is abundant in butter), lauric acid didn't appear to raise heart risk quite as much. But that's likely because American diets typically don't include very much lauric acid, so it's harder to detect any effect, Dr. Sun notes.
Tropical diets are different
Coconut oil proponents point to studies of indigenous populations in parts of India, Sri Lanka, the Philippines, and Polynesia, whose diets include copious amounts of coconut. But their traditional diets also include more fish, fruits, and vegetables than typical American diets, so this comparison isn't valid, says Harvard Medical School professor Dr. Bruce Bistrian, who is chief of clinical nutrition at Beth Israel Deaconess Medical Center.
Some of the coconut oil available in stores is labeled "virgin," meaning that it's made by pressing the liquid from coconut meat and then separating out the oil. It tastes and smells of coconut, unlike the refined, bleached, and deodorized coconut oil made from the dried coconut meat used in some processed foods and cosmetics. Virgin coconut oil contains small amounts of antioxidant compounds that may help curb inflammation, a harmful process thought to worsen heart disease. But to date, proof of any possible benefit is limited to small studies in rats and mice, says Dr. Bistrian.
In contrast, there's a wealth of data showing that diets rich in unsaturated fat, especially olive oil, may lower the risk of cardiovascular disease, Dr. Sun points out. The evidence comes not only from many observational studies (like those in the aforementioned BMJ report) but also a landmark clinical trial from Spain, which found that people who ate a Mediterranean-style diet enhanced with extra-virgin olive oil or nuts had a lower risk of heart attack, stroke, and death from heart disease than people who followed a low-fat diet.
Of course, there's no need to completely avoid coconut oil if you like the flavor. Some bakers use coconut oil instead of butter in baked goods, and coconut milk is a key ingredient in Thai cooking and some Indian curry dishes. Just be sure to consider these foods occasional treats, not everyday fare.