Typically, those individuals promoting the myth that low cholesterol levels are dangerous and the topsy-turvey "science" that saturated fat and high cholesterol are not bad, but good, are those individuals and health advisors advocating diets high in animal products, such as the Atkins devotees. Unfortunately, this advice is not merely incorrect; it is dead wrong for hundreds of individuals who heed such dangerous advice and die of heart attacks every day.
When it comes to coronary artery disease, there may be no such thing as lowering total blood cholesterol levels too far. Another recent study, published in the journal Circulation, found that the arteries in male patients with a total cholesterol level as low as 155 mg/dl benefited significantly from cholesterol-lowering medication as well.1 Both regression of atherosclerosis and a dramatic reduction in heart attacks were seen in the group treated.
While some research in the past has raised questions about the safety of very low cholesterol levels, no danger has been proven in larger, more dependable investigations. The new reports, documenting the effectiveness in saving lives with more substantial cholesterol lowering, fuels an ongoing debate about how aggressively to treat heart disease patients whose cholesterol levels are better than average and whether aggressive cholesterol lowering is valuable even in young healthy adults without signs of heart disease.
In the past, it was thought to be good enough to have a cholesterol level better than average. Until recently, doctors advised their patients to strive for a total cholesterol lower than 200 mg/dl. Eventually, this advice was found to be lacking and now we know that it is not very good to be average in a population that ubiquitously develops atherosclerosis. On autopsy, almost all American adults demonstrate significant coronary artery disease (2) and even 78% of young trauma victims who died before the age of 35 demonstrated significant atherosclerosis on autopsy.3 If you eat American food, you will inevitably develop American diseases. It is rare that someone can escape from the biological laws of cause and effect.
Clearly, if we attempt to rival the low cholesterol of populations that eat mostly natural plant foods and do not have heart disease, we are always looking at total cholesterols below 150 mg/dl. The average cholesterol level in rural China, as documented in the massive China Cornell Project, was 127 mg/dl. Heart attacks were rare, and both cancer and heart disease rates plummeted as cholesterol levels fell, which reflected very low animal product consumption. The lowest occurrence of heart disease and cancer occurred in the group that consumed plant-based diets with less than two servings of animal products per week.
There was some controversy years ago about striving for lower, protective cholesterol levels after some studies in the eighties noted that depression, suicide, hemorrhagic stroke, cancer, and death from other causes, were higher in some groups with very low cholesterol groups. Larger, recent investigations studying larger populations did not confirm these questionable findings.
When investigators looked more carefully at the individual characteristics of the studied populations they were able to explain the earlier findings. This issue is complicated because these studies evaluated individuals who were eating the modern American diet, rich in saturated fat and other components of animal products that raise cholesterol, and low in plant derived anti-oxidants, phytochemicals, and essential fatty acids that improve cholesterol ratios. Those who demonstrated very low (ideal) cholesterol levels, while following the traditional, modern, cholesterol-promoting diet, may actually have a compromised health status or undetected chronic disease.
For instance, we know cancer causes less cholesterol production in the liver. Low cholesterol may be associated with cancer, but does not cause it. Researchers showed that cholesterol starts to fall up to 8 years prior to a person dying of cancer, and that those with the greatest drop in cholesterol in a 4 year period without dietary improvements to lower cholesterol were those most likely to develop cancer.4 The low cholesterol did not cause the cancer; the cancer caused the low cholesterol. Those who work to lower cholesterol by avoiding saturated fats, eating a high nutrient diet with lots of raw vegetables, cooked green vegetables, and beans do not have a pathological condition causing their low cholesterol. They earned it.
This is why in rural China where the diets are nearly vegetarian, the average cholesterol levels are low and you see lower cancer rates, not higher. Those with the lowest cholesterol in the China study actually had the lowest cancer rates as well. Obviously, there is a difference between one who has a low cholesterol because his dietary style earns it, and one whose cholesterol seems unjustifiably low on a modern heart-disease-promoting diet that almost everyone in the west eats.
1. Jukema JW, Bruschke AV, van Boven AJ, et al. Effects of lipid lowering by pravastatin on progression and regression of coronary artery disease in symptomatic men with normal to moderately elevated serum cholesterol levels. The Regression Growth Evaluation Statin Study (REGRESS).Circulation 1995;91(10):2528-2540.
2. Shirani J, Yousefi J, Roberts WC. Major cardiac findings at necropsy in 366 American octogenarians. Am J Cardiol 1995;75(2):151-156.
3. Joseph A, Ackerman D, Talley JD, et al. Manifestations of coronary atherosclerosis in young trauma victims--an autopsy study. J Am Coll Cardiol 1993;22(2):459-467.
4. SJ Sharp, SJ Pocock. Time trends in serum cholesterol before cancer death. Epidemiology 8: (MAR 1997):132-136. M Zureik, D Courbon, P Ducimetiere. Decline in serum total cholesterol and the risk of death from cancer. Epidemiology 8: 2 (MAR 1997):137-143.