The two faces of the 'good' cholesterol.

Although a low level of high-density lipoprotein (HDL) cholesterol is a useful clinical predictor of coronary heart disease, raising the HDL cholesterol level does not necessarily lower this risk. Part of the explanation for this paradox may be that, under certain conditions, HDL either can be less functional as an antioxidant or can even enhance the oxidation and inflammation associated with atherosclerotic plaque. Thus, the functional properties of HDL--not simply the level--may need to be considered and optimized.