The higher the level of LDL, the greater the risk of coronary heart disease. Once LDL is inside the artery, it can be oxidized by cells that produce reactive oxygen. Oxidation can alter or destroy substances found in food and important in the body. It is the same process that causes some oils to turn rancid when exposed to air. Vitamins C and E, because they can be oxidized themselves, act as bodyguards of oxidizable substances, sacrificing themselves to save another life.
Chemists call such bodyguards antioxidants.
What we wanted to do with this research was look at the effect of antioxidant vitamins on the process. Nobody had looked at the effect of vitamin C on LDL oxidation. Dr. Jialal's research partners were Dr. Scott M. Grundy, director of the Center for Human Nutrition, and Dr. Gloria Lena Vega, associate professor of clinical nutrition. Macrophages cannot take up normal LDL, but oxidized LDL binds itself to special receptors on the cells. These receptors take up oxidized LDL and its cholesterol in an unregulated fashion and become engorged with LDL cholesterol.