Familial hypercholesterolaemia is a genetic disorder that results in elevated level of plasma lipoproteins. Having the disease causes a build up of cholesterol in the arteries that results in the formation of atherosclerosis. The resulting atherosclerotic lesions can increase the risk of cardiovascular disease, and premature mortality from cardiac events is common with hypercholesterolaemia. This sequence of event is often used as evidence that cholesterol is involved in the development of cardiovascular disease and that cholesterol lowering drugs such as statins are beneficial. In fact, one of the very first epidemiological studies investigating causes of cardiovascular disease, the Framingham study, included those with familial hypercholesterolaemic in order to allow the association between plasma cholesterol levels and cardiovascular disease to be larger than it would normally have been. Since this time, the cholesterol theory of cardiovascular disease, often called the diet heart hypothesis, has become hugely profitable for the pharmaceutical industry.
Familial hypercholesterolaemia is a fairly well known genetic disease and is covered in many biochemistry and medical textbooks in great detail. However, there exists a lesser know sister disorder that receives in comparison, very little coverage. Phytosterolaemia, sometimes called sitosterolaemia, is characterised not by high plasma levels of cholesterol, but by high plasma levels of plant sterols. Plant sterols have almost the same structure as cholesterol, but differ very slightly. This allows sterols to be treated by the body in a similar way to cholesterol. Phytosterolaemia result from a genetic mutation to a gene that codes for a gut transporter that would normally prevent absorption of most dietary sterols. In such individuals, deficiency of the transporter removes the inhibition for absorption, The result is that plasma concentrations of sterols rise up to thirty-fold, and the oversupply of sterols causes accumulation in tissues, including the arteries of the heart. This results in atherosclerosis and increases the risk of cardiovascular disease in the same way as familial hypercholesterolaemia.
A new approach to lowering cholesterol involves the use of phytosterols. Taken in specially made spreads, as supplements, alone and in combination with statin drugs, sterols therapy isconsidered beneficial to the health because of its cholesterol lowering ability. Sterols are thought to do this by competing with cholesterol in the gut and thus decreasing absorption. However, this apparent benefit, the replacing of cholesterol with sterols, is illogical and absurd. If familial hypercholesterolaemia is used as evidence that cholesterol causes heart disease, why is not phytosterolaemia used as evidence that phytosterols cause cardiovascular disease? Both disorders have the same aetiology, cause accumulation of lipids in the arteries of the heart and increase risk of cardiovascular disease. Yet cholesterol is detrimental and must be lowered, and sterols are beneficial and must be supplemented. Either they must both be detrimental, or both be harmful, logically it cannot be as described. Even more worrying, is the fact that the mortality benefits of sterol therapy has never been tested, and so no one knows the effects of treatment.
Welcome to another real-time experiment, subject 6079.
RdB