Cuckoo for coconuts? Hold on

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My patients ask me about coconut oil all the time. They see talk shows and websites claiming that it helps with everything from losing weight to preventing diabetes, atherosclerosis, heart disease and a host of other ailments.

If only losing weight and avoiding disease were that easy.

Unfortunately, there just isn't much credible research to support these claims -- not yet anyway. Scientific knowledge is always evolving, and as a dietitian focused on preventing and treating heart disease, I will be watching this issue closely. But for now, here's what the most current, science-based evidence tells us:

• Coconut oil is a fat, and like all fats, it is very high in calories; you'll get 117 calories in just one tablespoon of it. Eat a lot of anything that's high in calories, and you are more likely to gain weight than to lose it.

• Almost 90 percent of the fat in coconut oil is saturated fat -- that's more than twice the saturated fat in lard, which is about 39 percent saturated. The science to date tells us that eating saturated fat harms your heart and blood vessels, rather than helping them.

What about those medium-chain fatty acids?

Many defenders of coconut oil base their beliefs on studies of medium-chain fatty acids, or MCTs (the T is for triglycerides, another word for fat). Studies of pure, 100 percent medical-grade MCT oil do show that the body processes these fatty acids differently, using them for fuel rather than storing them as fat. If coconut oil were 100 percent MCTs, we might be on to something. Unfortunately, there isn't a naturally occurring food on the planet that comes close to that level. In coconut oil, MCTs are a minor player, accounting for only about 10 to 15 percent of its total fat content. That's not nearly enough to trigger the weight loss benefit that proponents claim. When you factor in the calories and the much higher levels of saturated fat in coconut oil, any potential MCT benefit is significantly outweighed.

As for the other fatty acids in coconut oil, one type has been shown to raise HDL, the beneficial type of cholesterol; however, even that benefit is outweighed by the main fatty acids in coconut oil, which raise LDL, the harmful cholesterol.

So should you avoid coconut oil like the plague?

Not at all — there is room in a healthy, balanced diet for a little coconut oil, just as there is room for a little butter or bacon. Like all saturated fats, just use it in moderation. Most dietitians recommend limiting saturated fats to no more than 10 percent of your total daily calories.

One advantage of coconut oil is that it stands up well to high-temperature cooking, thanks to its high smoke point. In this one use, it beats olive oil, whose heart-friendly unsaturated fats break down and become less healthy at high temperatures. But — and isn't there always a but? — there are still better choices. Rice bran oil, used in many Asian restaurants, as well as vegetable and peanut oils, are all very good for frying and high-temperature cooking, and contain much less saturated fat than coconut oil.

Coconut water?

Some of my patients enjoy drinking coconut water after a workout, because it provides a small amount of electrolytes. While regular water is a lower-calorie choice, coconut water isn't too bad. It avoids the high calories and fat of coconut oil since it comes only from the liquid, rather than the meat, of the coconut. One cup has 46 calories, so if you like it, why not? Just read the label to make sure you avoid brands that add sugar.

As for coconut milk, it uses both the meat and the liquid of the coconut, so it falls into the use-only-in-moderation camp. One cup delivers nearly 450 calories and 48 grams of fat, 42 of which are saturated -- that's about a quarter of the calories and three times the recommended limit of saturated fat for an average woman for an entire day.

Go with what we know

As I mentioned, our understanding of what's healthy and what's not evolves every time a new, well-designed study comes out. Many of the studies supporting coconut oil as a miracle food fall apart quickly under close scrutiny. But the research continues. The saturated fat in coconut oil does appear to be somewhat different from other saturated fats — but whether that is a healthful, harmful or neutral difference remains to be seen. Another area of research is now theorizing that heart disease risks may have more to do with carbohydrate intake than saturated fat; this, too, is still under investigation. Until we know more, the cautious path is to go with what we know from the most current, credible and conclusive research. And right now, the research on coconut oil does not support the hype.

So if you like coconut oil, go ahead and have a little — but just a little. And don't expect miracles.

Jamie Libera is an RD, LD and cardiac dietitian with Providence Nutrition Services.