This past weekend I was debating with my daughter who is a nutrition and fitness expert about the merits and heart risks of coconut oil. She blogs and posts on-line extensively, and has a popular web site and an Instagram with over 60,000 avid followers (check out http://mindovermunch.com/). As a cardiologist and lipid specialist, the dogma I was taught is that saturated fat is bad for your heart, and because coconut oil is 90% saturated fat, it is especially bad. My daughter challenged me on this, citing a renewed interest in the nutrition and fitness community on the health benefits of coconut oil. So, I set out to do some research and find out the truth.
Coconut oil is indeed more than 90% saturated fat, containing about 12 grams per tablespoon. Compare this to a tablespoon of butter which is 63% saturated fat, with 7.2 grams or lard which is 40% saturated fat with about 6 grams of saturated fat. However, about half of the saturated fat in coconut oil is composed of the medium chain triglyceride (MCT) fatty acids, lauric and myristic acid. Unlike the animal fat-derived long chain saturated fatty acids, the MCT’s appear to increase HDL cholesterol (good cholesterol) and are easier to metabolize and digest. This may make coconut oil one of the better saturated fats.
Recent research in small groups of subjects appears to support some health benefits of coconut oil. A small study of 40 women found that compared to those using soybean oil as their primary cooking oil, those women using coconut oil raised their HDL levels and lowered their total cholesterol. Since MCT’s are easier to digest, they are available as quick energy sources, and more quickly convert to ketone bodies. As a result, MCT’s may assist in curbing appetite, promoting weight loss and improving metabolism in much the same way as a low carbohydrate/high protein diet does. Indeed, several small studies have found that subjects consuming one ounce of coconut oil per day had lowered weight, BMI, waist circumference and abdominal fat. Coconut oil has also been touted to improve immunity, thyroid function, blood sugar, memory and lower the risk of Alzheimer’s disease and epilepsy.
However, before we endorse coconut oil as the “superfood” that Dr. Oz would have you believe, keep in mind it is still a saturated fat. Coconut oil, like all foods high in saturated fat, raises LDL cholesterol (bad cholesterol). Diets high in saturated fats consistently have been shown to increase the risk of heart attacks, strokes and death due to heart disease. Recall the enthusiasm in the 1990’s that accompanied the Atkin’s diet. The diet was very effective in promoting weight loss, but permitted unlimited amounts of fat intake. Some of its diet plans had over 60% saturated fat. At its peak, one out of every eleven people in North America was on the Atkin’s diet. Its popularity began to wane when studies like a 10-year study in Sweden found that men on an Atkin’s diet had a 40% increase in the risk of heart-related death.
Proponents of coconut oil also cite isolated groups of South Pacific Islanders like the Kitavans and Tokelauans, who derive 60% of their calories from coconuts and are in excellent health and have a very low prevalence of heart disease. However, the incidence of obesity, hypertension and cardiovascular disease is extremely high in the more homogeneous populations of Hawaiians and Polynesians who also have diets high in plant and fish-derived fats. So these population observations are far from conclusive.
The American Heart Association and the U.S. government’s 2010 Dietary Guidelines suggest limiting total fat intake to no more than 25-35% of calories, and saturated fats to no more than 7-10% of total calories. There is reasonably sound research to support this recommendation. In fact, the studies showing a benefit to coconut oil all recommended daily intakes of coconut oil within the recommended range of keeping saturated fat calories to under 10%. Despite its beneficial effects on HDL and metabolism, no study of coconut oil has shown that it reduces the risk of heart attacks, strokes or death.
So what should you do? It is likely that coconut oil is better than butter, and certainly better than trans-fats. It is probably not as healthy as the polyunsaturated vegetable oils, which both lower LDL and raise HDL. However, up to the recommended limit of permitting 10% of your daily calories to come from saturated fat, coconut oil is likely not an unwise choice. One tablespoon of coconut oil provides about 100 saturated fat calories. So you can enjoy coconut oil if it is your preference by using it in moderation, and sticking to the recommended limit by using no more than 1-2 tablespoons per day, assuming you have no other sources of saturated fat. Also keep your eyes open for further research evaluating its long-term effects and how it compares to other saturated fats.
Coconut oil is a good cooking option as it can withstand heat better than other types of plant oils. It works well with baked goods, vegetables and is a good addition to oat meal. At room temperature, it is a white solid and looks much like shortening. It is not good for liquid applications since once it cools, it solidifies very quickly. So, it would not be a good choice as a salad dressing.
For more information, get the book Don’t Let Your Heart Attack!, available on Amazon, Barnes & Noble and iTunes.