Coconut oil does not help a person lose weight, lower blood sugar levels, or dampen down harmful inflammation (Circulation, Jan 13, 2020;141:803–814). The authors reviewed 17 studies involving 730 healthy participants, and found that coconut oil increased blood levels of the harmful LDL cholesterol by 10.47 mg/dL, much more than the increase from soybean, olive, safflower, canola or palm oils. More than 92 percent of the fat in coconut oil is saturated fat, which raises the bad LDL cholesterol more than other vegetable oils do, and is associated with increased risk for heart attacks. Yet 72 percent of North Americans think that coconut oil is a healthful food, while only 37 percent of registered nutritionists agree with them (New York Times, July 16, 2016).
An earlier review of 21 studies showed that replacing coconut oil with unsaturated fats reduced blood risk factors for heart attacks (Nutrition Reviews, Apr, 2016;74(4):267–280). Promoters of coconut oil often cite studies showing that people in societies that eat a lot of coconut oil are not at increased risk for heart attacks. However, these people did not eat the heart-attack-provoking “Western Diet”. They were not eating lots of mammal meat, processed meats and sugar-added processed foods. They also got much of their coconut oil from fresh coconut flesh, rather than from commercially processed coconut oil.
Doesn’t Coconut Oil Raise the Good HDL Cholesterol?
Coconut oil raises blood levels of the healthful HDL cholesterol by 4 mg/dL, but several other studies show that raising HDL cholesterol does not prevent heart attacks. One study of more than 100,000 patients showed that raising HDL cholesterol does not reduce heart attack risk (BMJ, 2014;349:g4379), and another study showed that people with genetically high HDL cholesterol are not at reduced risk for heart attacks (Lancet, 2012;380:572–580).
Aren’t the Medium Chain Triglycerides in Coconut Oil Healthful?
Nearly half of the saturated fats in coconut oil are medium chain triglyceride fatty acids (MCFAs) that have been reported to be different from shorter and longer chain saturated fats because they appeared not to raise blood levels of the harmful LDL cholesterol (J Am Coll Nutr, Oct 2008;27(5):547–552). However, other studies show that MCFAs in coconut oil do raise LDL cholesterol more than other plant oils such as palm oils (Am J Clin Nutr, 1997;65:41–45). Today the majority of studies show that coconut oils do raise blood levels of the harmful LDL cholesterol (JAMA, published online April 8, 2020).
The authors of this recent study conclude that, “Coconut oil should not be viewed as healthy oil for cardiovascular disease risk reduction and limiting coconut oil consumption because of its high saturated fat content is warranted.” Eating coconuts has not been shown to increase risk for heart attacks, but coconut oil does contain saturated fats that raise blood levels of LDL cholesterol.
I believe that everyone should limit deep-fried foods (foods cooked by submerging in vegetable oil at high temperatures). If you must deep-fry a food, choose an oil with a high smoke point, such as avocado, sunflower seed or peanut oil. Coconut oil has a low smoke point (350°F), so it should not be used for deep frying. Coconut oil and other low-smoke-point oils such as olive oil can be used for brief sauteing of moist foods such as onions, green peppers, garlic and celery, or stir-frying combinations of food that include plenty of vegetables. They can also be used uncooked for salad dressings, dips and sauces, or in recipes with a high water content such as soups. See my Guide to Vegetable Oils.
Your total diet is far more important than whether you eat or restrict coconut oils. Whatever vegetable oils you choose, they should be a very minor part of your diet, perhaps a few tablespoons a day. Preventing heart attacks involves following an overall heart-healthy diet that includes a wide variety of plants and restricts mammal meat, processed meats, fried foods, sugar-added foods and all sugared drinks including fruit juices.