Healthcare and nutrition fads are an unfortunate fact of life. People are always looking for miracle cures and for clear, defined villains they can blame for illness and try to avoid. The media contributes to the process of fads coming and going by ignoring subtlety, nuance, and uncertainty in scientific research and presenting every new study as a dramatic paradigm shift that replaces existing error with absolute truth. The slow, halting, progress in real knowledge brought about in fits and starts by the scientific process and the community of science over time is still real progress, and it has yielded true revolutionary improvements in health. But it is harder to understand and to narrate and less emotionally satisfying than quick-well-quick schemes and medical bogeymen that we can blame for all our ills.
Healthcare fads in humans readily make the transition to fads among pet owners. Even though human health problems, and their causes and solutions, are often quite different from the health problems our pets experience, people naturally tend to think that if something is good or bad for them it must be similarly good or bad for their pets. Often, even when there is some real scientific evidence for the benefits or risks of some healthcare practice in people, there is little or no evidence to support claims about these practices applied to our pets. Extrapolation from people to pets is inevitable, but it is also very risky.
One fad that has been going on for a few years now in human nutrition, and which is being touted for pets as well by proponents of alternative medicine, is the use of coconut oil to prevent or treat a wide variety of health problems. Some sites, including the ever-unreliable Dogs Naturally Magazine, claim coconut oil can prevent or treat skin disease, allergies, gastrointestinal problems, infections, diabetes, and cancer, and can even help with weight loss. Let’s have a look at this supposed “superfood” and what it can or can’t do for us and our pets.
What Is It?
Coconut oil comes, not surprisingly, from coconuts. Conventionally, it has been produced from dried coconut meat through a process that often includes hydrogenation, however sites promoting coconut oil for health often prefer “virgin” oil obtained through cold pressing of fresh coconut. Coconut oil consists primarily of saturated fats, mostly a fat called lauric acid. These fats range from long-chain to medium-chain triglycerides (MCT). It does not contain trans-fats.
The types of fat in coconut oil are the center of discussions about its health effects. At one time, it was considered the worst type of dietary fat because saturated fats had been generally linked to increased risk of cardiovascular disease (CVD). As the evidence has accumulated and been refined, however, it has turned out that different kinds of saturated fats have different potential health effects. Trans fats and long-chain fatty acids appear to elevate the type of cholesterol (low-density lipoproteins) which increase CVD risk. Other fats, such as medium-chain triglycerides, seem to increase high-density lipoproteins, which may be protective against CVD. Many foods once considered likely to increase CVD risk, such as nuts and avocados, are now believed to be neutral or even possibly protective with regard to CVD.
Some of the fats in coconut oil are MCTs, and this is the foundation for most claims about the potential health benefits of coconut oil. However, only about 15-20% of the fats in coconut oil are true MCTs, and the effects of the most prevalent, lauric acid, on cholesterol are the subject of debate.
Most of the claims about health effects in humans for coconut oil focus on prevention of heart disease, treatment of diabetes and Alzheimer’s disease, and beneficial effects on weight loss. However, all kinds of other dramatic claims are easily found. In pets, CVD is a far different and generally less common entity, so the claims are more general, focusing especially on skin health, gastrointestinal health, and infections, though some vets claim they have cured cancers with it.
Does It Work?
The evidence for beneficial effects from coconut oil in humans is almost all indirect. Studies looking at MCTs in the diet show some potential benefits, and the proponents of coconut oil then extrapolate to assume that this product must have these benefits because it contains MCTs. This is a tenuous type of extrapolation at best. Claims for coconut oil are also often supported mostly by in vitro or lab animal research, which unfortunately can only prove an effect is possible, not that it will actually, reliably, and safely be seen in human patients.
One excellent summary of the existing research summarizes the evidence this way:
Coconut oil is not a cure-all. Research supporting claims of its role in preventing, reducing risk for, or curing HIV/AIDS, diabetes, thyroid disease, or Alzheimer’s disease is sparse or non-existent. There is little evidence to suggest it has a significant effect on inflammation or bacterial infection when consumed in food. And the pre-clinical research in cancer is mixed. Considerable research is needed to determine whether such claims may one day be substantiated. Further research may also help to clarify the potentially beneficial effect of coconut oil on HDL cholesterol levels and waist circumference. In order to reduce cardiovascular disease risk through diet, it will be necessary to determine the appropriate balance of dietary fatty acids that will favorably affect a range of cardiovascular risk factors. It is possible to include coconut oil in a healthful diet. Rather than focus 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. It should not replace a significant amount of other plant oils in the diet. Those who enjoy the flavor of coconut oil may consider using it in place of butter or shortening, or paired with other cooking oils. Coconut oil can be one of a wide variety of plant-based foods that are included to support health and wellness, keeping in mind that only small amounts should be consumed.
As usual, there is almost no research available in dogs and cats, and the claims made for coconut oil in these species are extrapolated from human medicine, where we have seen the evidence is not strong to begin with. One study that added coconut oil to dog food to see if it would help with weight loss found that dogs on the diet with coconut oil lost less weight and had more body fat than dogs on diets with other sources of fat. Another study looked at various fats, including coconut oil, and exercise and how they affected the odorant detecting ability of dogs. It isn’t clear this has any clinical relevance to anything, but in any case the dogs getting the coconut oil seemed to have some decline in odorant detecting ability.
Some research has suggested that coconut oil shampoo may be effective against some common parasites in dogs. Another study indicated effectiveness against mange mites. However, both studies were conducted by the same research group with a strong bias in favor of such “natural” treatments and without some key controls for bias, so they need to be replicated to confirm these findings.
There is no clinical research of any kind showing a significant benefit from dietary or topical coconut oil in the prevention or treatment of any significant health problem.
Is It Safe?
No significant short-term risks have been identified for dietary coconut oil in humans in reasonable quantities, though diarrhea and other gastrointestinal problems have been reported. Long-term safety and effect on obesity, CVD< and other health risks hasn’t been determined.
Similar gastrointestinal symptoms have been reported in dogs, and there are anecdotal reports of more serious problems such as pancreatitis. There is no controlled research evidence investigating the safety of coconut oil in dogs and cats.
There are some theoretical reasons to think the types of fat found in non-hydrogenated coconut oil might have health benefits in humans, but there is no conclusive research to support this. There is virtually no research on coconut oil in dogs and cats, apart from some studies looking at topical use for treatment of parasites. Therefore, the health effects, both risks and benefits, are unknown and supported only by unreliable anecdotal evidence.