LDL-Cholesterol And Dietary Fat

In the last century there was a lot of research into the connection of diet with coronary artery disease. Focus has changed over the years from one dietary factor to another. During the last half of the twentieth century the emphasis was on the effect of saturated fat in the diet on coronary artery disease. Because of the association of a high blood LDL-cholesterol with coronary artery disease, short term dietary studies have been done to find diets that can lower blood LDL-cholesterol.

The Study

Cholesterol Spacefill
Cholesterol
One of the diets showing modest effect was the NCEP diet. This diet has evolved over the years. It was based on the concept that less fat in the diet would lower cholesterol, known to be associated with atherosclerotic plaques and coronary artery disease. However a study done in 2003 (1) compared the LDL lowering ability of one version of the NCEP diet to a statin drug, lovastatin.

Statin drugs have been shown to reduce blood cholesterol and subsequent heart events in large randomized controlled studies. Early diets involving eating less fat showed modest improvements in blood cholesterol and cardiac events. This study tried to determine if a diet could do as well as a drug.

By delivering plant sterols, fiber, soy protein and nuts, this diet was able to reduce LDL-cholesterol as much as 20 mg of lovastatin. It also lowered the overall coronary heart disease risk score based on a well accepted risk equation.

No Change In Dietary Fat

The diet was able to do this without lowering the fat content of the diet. In fact, the total fat, saturated fat and cholesterol intakes were slightly more in the experimental diet than the control diet. This study showed that without lowering fat intake, a diet can be designed to lower the risk of coronary artery disease.

The researchers felt this diet reduced cholesterol absorption, and cholesterol formation in the liver. And it may have increased the loss of cholesterol from the body. Some prior basic science studies indicated these mechanisms as possible ways the components of the diet worked.

Sadly, the study did not determine the sodium and potassium content of the diet. Because of this we cannot know if a change in potassium and sodium intake contributed. But it does show that a low fat diet is not the only consideration for reducing the risk of heart disease.
_______________________
1. Effects of a dietary portfolio of cholesterol-lowering foods vs lovastatin on serum lipids and C-reactive protein. Jenkins DJ, Kendall CW, Marchie A, Faulkner DA, Wong JM, de Souza R, Emam A, Parker TL, Vidgen E, Lapsley KG, Trautwein EA, Josse RG, Leiter LA, Connelly PW. JAMA. 2003 Jul 23;290(4):502-10.