Good fats protect your arteries

It used to be that all fat was bad but we now know that this is not the case. Research has shown that eating foods higher in polyunsaturated and monounsaturated fats like those in safflower oil, olive oil and fatty fish is protective. On the other hand we know that eating a diet that high in saturated fats can lead to heart disease. Meals made with lard or butter, greasy hamburgers and fried foods as well as super premium ice cream are the types of foods linked to atherosclerosis.

Researchers are not clear on precisely what the mechanism is, however, that leads saturated fats to promote the build up of atherosclerotic plaque on the inside of arteries. A study led by Stephen Nicholls explored one possible mechanism (JACC 2006;48(4):715-720).

Healthy subjects between the age of 18 and 40 agreed to participate by eating two separate meals. Both meals consisted of a slice of carrot cake and a milkshake that contained 1 gram of fat per kilogram of body weight. The difference was in how the meals were prepared. One used safflower oil that is very high in polyunsaturated and monounsaturated fats. The other contained coconut oil at almost 90% saturated fat.

The meals were consumed after an overnight fast and the testing of each was scheduled one month apart. The researchers collected blood from the participants 3 and 6 hours after the meal to look at the attributes of HDL cholesterol. The most important of these properties evaluated was the ability of the HDL molecule's anti-inflammatory potential.

At the same time the blood flow in the forearms of participants was studied. While flow did appear to decrease in the arteries after the saturated fat meal as compared to he polyunsaturated meal this was not found to be statically significant.

There was, however, a marked change in the anti-inflammatory capicity of the HDL. The researchers found a marked decrease in such ability when the saturated fat meal was consumed. These anti-inflammatory properties are those that protect the blood vessels from the build up of atherosclerotic plaque. Eating the meal high in polyunsaturated fats actually enhanced these protective character of the HDL molecules.

What this means for you

While the researchers are not sure of the exact mechanism, they did find that eating a single meal high in saturated fat impaired the anti-inflammatory properties of HDL Cholesterol. The same meal made with polyunsatured fats appears to protect the arteries.

First posted: August 11, 2006