IS IT DANGEROUS TO HAVE LOW PLASMA-CHOLESTEROL OR TO DECREASE IT TO ALOW-LEVEL

Meta analyses of results of number of follow-up studies conducted in d ifferent geographical areas of the world and the data or primary and s econdary prevention of ischemic heart disease using cholesterol loweri ng drugs or ileal bypass surgery give grounds for the following conclu sion: low or lowered level of blood plasma cholesterol cannot be the c ause of complications or death from noncardiovascular diseases. The as sociation of low blood cholesterol with high cancer mortality, risk of violent death and mental disorders described in some papers has no ca usal character. This association can be explained either by the impact of other factors (smoking, alcohol intake, etc.) which level is high in subjects who fall in the lower end of cholesterol distribution, or to the fact that low cholesterol concentration is a consequence of the pathology in question. This conclusion is also confirmed by the data on: a) saturation of cells of different organs and tissues with choles terol when its content in blood is much smaller than a ''low'' level; b) stable concentration of cholesterol in cell membranes irrespective of its level in blood; c) very low rate of cholesterol turnover in the brain.