Tropical oils don't boost some heart risk markers

Tropical oils may be sources of saturated fat, but a small study suggests that they do not boost certain markers of trouble in the blood vessels the way animal fats do.

In general, experts advise people to limit saturated fat in their diets because it raises blood cholesterol levels and has been linked to an increased risk of heart disease.

Meat and full-fat dairy products are probably the best-known sources of saturated fat, but certain vegetable oils - like palm and coconut oils - contain it too.

Different saturated fats are not exactly alike, however. And in societies where those tropical oils are used liberally, heart disease is less of a problem compared with Western countries, noted Phooi Tee Voon, a researcher at International Medical University in Kuala Lumpur, Malaysia, who led the new study.

In the study, Voon's team followed 45 healthy Malaysian adults who spent five weeks on each of three diets: in one their main fat source was palm oil; in another it was coconut oil; in the third it was olive oil - an unsaturated fat that's considered heart-healthy.

The researchers found that regardless of the fat source, participants' blood levels of certain inflammatory proteins remained the same.

That's important because at high concentrations, those proteins - which include homocysteine, C-reactive protein and others - are thought to damage the blood vessels and contribute to heart disease.

When it came to cholesterol, study participants showed no increase while on the palm-oil diet, but did see their numbers creep up while using coconut oil - though that included an increase in "good" HDL cholesterol.

So should you feel free to swap your olive oil for the tropical versions?

"I'd say, hold the phone on that," said Roberta Anding, a registered dietitian and spokesperson for the American Dietetic Association.

A big limitation is that the study participants were on carefully controlled diets, explained Anding, who also directs sports nutrition at Texas Children's Hospital in Houston.

The researchers supervised breakfast and lunch, and doled out packaged dinners. It was "very nicely controlled," Anding said, in order to isolate the effects of the different fats - which is a good research design.

"But that's not how people eat in the real world," Anding said.

In addition, people in the study followed a traditional Malaysian diet - consisting of rice, chicken, fish and vegetables.

As part of a Western meat-and-potatoes diet already high in saturated fat and refined carbohydrates, palm and coconut oils might have quite different effects, according to Anding.

"I think if you were to keep eating your hamburgers and your fries, and then add coconut and palm oils, you could create the perfect storm," Anding said.