Few food controversies are as heated as the one over coconut oil. Some say the saturated fat in it will do you in; others say it will cure you of everything from obesity to Alzheimer’s. The truth, of course, is far more nuanced.
Before getting into the weeds, it’s important to remember the inherent limitations of judging the healthfulness any one food or ingredient. Humans eat combinations of foods that make up complex diet patterns, not just one thing. So we have to consider the effects of total diet, not just the one food. Then there are other habits -- exercise, smoking, drug use, etc. Not to mention differences in people -- age, sex, size, genetic variants, health conditions, medications, and on it goes. So the best data we have to assess the healthfulness of foods are short trials (group A gets coconut oil and group B gets olive oil, all else the same) as well as cultural comparisons (compare coconut oil eating cultures to non coconut oil eating cultures). It’s the job of nutrition researchers to examine the data, make sense of the competing variables, and come up with the most reasonable recommendations based on the evidence. And here it is.
First, where there is not enough evidence for many claims: No peer-reviewed research directly assesses the effects of coconut oil on Alzheimer’s disease, diabetes, HIV/AIDS, or thyroid function.
Antimicrobial properties: Evidence is inconclusive. The anti fungal and antimicrobial properties are attributed to monolaurin, which is made from the fatty acids found in coconut oil. But it is unclear whether the body actually converts the oil into monolaurin, and if so, whether it successfully kills or discourages harmful microbes in the body.
Cancer: Some studies have shown benefits using coconut oil, but not when compared to a placebo or another type of fat, so the positive outcomes may be due to the fat itself or simply increased calories.
Heart health: Nutrition scientists with IFIC provide an excellent summary on scientific literature. It is true that small, case-control studies have observed a lack of association between coconut or saturated fat intake and coronary heart disease in communities for whom coconut is an important part of the diet (here is a case where the overall diet pattern - in parts of the world where coconut oil is an important part of the native diet - may be the key to understanding this finding). Nonetheless, no clear health benefit of coconut oil has been seen in larger studies observing the effects of diet and heart disease risk.
If coconut oil research has taught us anything, it’s that not all saturated fats are created equal. Coconut oil may result in different blood lipid effects compared to other sources of saturated fats. This may be due to lauric acid, the specific saturated fat that is abundant in coconut oil, which appears to be considerably less harmful than the saturated fats found in animal sources. But what about effects in the context of unsaturated fats, which we know are heart-protective?
Compared to diets high in unsaturated fats, diets high in saturated fats from coconut oil have been shown to increase total and LDL (bad) cholesterol, but also improve HDL (good) cholesterol. A more favorable overall effect on total, LDL, and HDL cholesterol together has been demonstrated with partial replacement of coconut with unsaturated fat sources.
Main takeaway — increasing coconut oil is not likely to ward off heart disease. The cardiovascular effects of coconut oil in humans are complicated and still unfolding, and more research is needed to understand the appropriate role for coconut oil in a heart healthy diet.
Weight loss: Most claims about coconut oil and weight are based on the reported beneficial effects of its medium chain triglycerides (MCTs). About 58% of the fatty acids in coconut oil are MCTs—caprylic (7.4%), capric (5.9%) and lauric acid (44%). (Caprylic and capric acids have been touted as being more efficiently metabolized and less likely to be stored as fat. Even if there is some truth to this, since coconut oil contains primarily lauric acid—far less caprylic or capric—coconut oil itself cannot be assumed to have the same health effects as pure MCTs.) There are very few human studies available on coconut oil and body fat loss. Those showing a benefit in waist circumference were performed on people following very low calorie diets, and often with no control group.
Anti-inflammatory effects: The predominant saturated fat in coconut oil, lauric acid, appears to be less inflammatory than the saturated fats found in animal foods like beef and butter. But that doesn’t mean that it has overall anti-inflammatory properties.
Preliminary evidence in animals suggests that coconut oil may protect against damage to the colon caused by inflammatory diseases of the digestive tract. However, other studies show no significant effects of coconut oil consumption on inflammation in humans. The evidence for the effects of coconut oil on inflammation is limited and quite mixed.
BOTTOM LINE?
Rather than focusing solely on the saturated fat content of this single food ingredient, it is important to acknowledge that coconut oil contains a blend of fatty acids and other nutrients. If you like the flavor and culinary properties of coconut oil, using it in small amounts as part of an overall healthful diet appears safe.
