Findings changing on coconut oil benefits

Q: I read on the internet that coconut oil is great for your cholesterol and has other health benefits. I thought coconut oil was very bad for you. What gives?

Here's the advice of Walter C. Willett, MD, of the Harvard School of Public Health, Department of Nutrition:

I'd use coconut oil sparingly. Most of the research so far has consisted of short-term studies to examine its effect on cholesterol levels. We don't really know how coconut oil affects heart disease. And I don't think coconut oil is as healthful as vegetable oils like olive oil and soybean oil, which are mainly unsaturated fat and therefore both lower LDL and increase HDL. Coconut oil's special HDL-boosting effect may make it "less bad" than the high saturated fat content would indicate, but it's still probably not the best choice among the many available oils to reduce the risk of heart disease.
Dr. Thomas Brenna, professor of nutritional sciences at Cornell University, has done a thorough review of the literature on coconut oil. He explains why coconut oil was given a bad name.

Most of the studies involving coconut oil were done with partially hydrogenated coconut oil, which researchers used because they needed to raise the cholesterol levels of their rabbits in order to collect certain data. Virgin coconut oil, which has not been chemically treated, is a different thing in terms of a health risk perspective. And maybe it isn’t so bad for you after all.

Most foods contain several different types of fat.

Saturated fat
Saturated fat is found mostly in foods from animals and some plants. Foods from animals include meats and dairy products. Plant foods that contain saturated fat include coconut oil, palm oil and cocoa butter. Saturated fat raises low-density lipoprotein (LDL) - the bad cholesterol - and high-density lipoprotein (HDL), the good cholesterol.

Unsaturated fat
Polyunsaturated and monounsaturated fats are the two unsaturated fats. They're found mainly in many fish, nuts, seeds and oils from plants. Some examples of foods that contain these fats are salmon, trout, herring, avocados, olives, walnuts and liquid vegetable oils such as soybean, corn, safflower, canola, olive and sunflower. Studies show that eating foods rich in unsaturated fats lowers LDL cholesterol and raises HDL cholesterol.

Trans fat
Most trans fat is made by adding hydrogen to vegetable oil through a process called hydrogenation, which makes the oil less likely to spoil. Using trans fats in the manufacturing of foods helps foods stay fresh longer, have a longer shelf life and have a less greasy feel. Hydrogenation is common in margarine and shortening. Trans fat is a cholesterol nightmare; it raises your LDL cholesterol and lowers your HDL cholesterol.

Why is coconut oil getting internet attention and a lot of buyers in health food stores? As Dr. Willett points out, coconut oil seems especially effective in giving HDL a boost.

There are several forces creating this phenomenon. The coconut oil industry is working hard to win public favor. There are scientists who are backing off from the damnation of coconut oil. And then there are vegans, who abstain from animal products. Many vegans use coconut oil as a butter substitute. Coconut oil is solid at room temperature.

[In my next column, we'll hear from the coconut-oil advocates.]