[Blood cholesterol levels and mortality in cancer]

Prospective studies carried out in different parts of the world, with the most extensive one comprising 360,00 American men followed up over a period of 7-8 years, have found that the total serum cholesterol level correlates inversely with subsequent mortality for cancer. On excluding the first years following the determination of cholesterol level this inverse relationship decreases or disappears completely. The cholesterol level keeps decreasing for at least two years prior to death caused by cancer. Patients suffering from a malignant process are frequently found to have very low cholesterol levels and that even when they are in a good nutritional condition. The effect of the preclinical stage of cancer on the metabolism of plasma lipoproteins is presumed to account for the inverse correlation observed between cholesterol level and cancer. The rapidly multiplying cancer cells require great amounts of cholesterol to build up their new membranes and therefore increase the activity of receptors binding plasma low-density lipoproteins (LDL). This mechanism speeds up the transfer of plasma cholesterol into cancer cells. According to some reports increased cholesterol supply by food enhances the risk of cancer both in humans and experimental animals. Changes in the nutritional pattern aimed at preventing ischemic heart disease (reduced intake of satured animal fat and cholesterol) may be associated with a lower risk for malignancy.