November 22, 2016

High Cholesterol May Be Good

People with high cholesterol live the longest.

This statement seems so incredible that it takes a long time to clear one´s mind to fully understand its importance. Yet, the fact that people with high cholesterol live the longest emerges clearly from many scientific papers. But let us take a look at heart mortality, the risk of dying from a heart attack if cholesterol is high.

Consider the finding by Dr. Harlan Krumholz of the Department of Cardiovascular Medicine at Yale University, who reported that old people with low cholesterol died twice as often from a heart attack as did old people with high cholesterol. Supporters of the cholesterol campaign consistently ignore his observation, or consider it as a rare exception, the result of chance among a huge number of studies finding the opposite.

But it is not an exception; there are now a large number of findings that contradict the lipid hypothesis. To be more specific, almost all studies of old people have shown that high cholesterol is not a risk fact for coronary heart disease. This was the result of a search in the Medline database for studies addressing that question. Eleven studies of old people came up with that result, and a further seven found that high cholesterol did not predict all-cause mortality either, and more such studies have been published since then.

It has been mentioned before, but it is worth repeating, that more than 90 percent of those who die from a heart attack or a stroke have passed the age of 65. You may also recall that high cholesterol is not a risk factor for women, or for a number of other population groups.

But there is more comfort for those who have high cholesterol. At least fifteen studies found that total mortality was inversely associated with either total or LDL-cholesterol, or both. This means that it is actually much better to have high than to have low cholesterol if you want to live to be very old.

Many studies have found that low cholesterol in certain respects is worse than high cholesterol. For instance, in nineteen large studies of more than 68,000 deaths, reviewed by David R. Jacobs and his co-workers from the Division of Epidemiology at the University of Minnesota, low cholesterol predicted an increased risk of dying from gastrointestinal and respiratory diseases. Most gastrointestinal and respiratory diseases have an infectious origin. Therefore, a relevant question is whether it is the infection that lowers cholesterol or the low cholesterol that predisposes to infection. You have probably already guessed what the directors of the cholesterol campaign have said, but is it true?

To answer that question David Jacobs´ group followed more than 100,000 healthy individuals in the San Francisco area for fifteen years. At the end of the study, those who had low cholesterol at the start of the study had been admitted more often to hospital because of an infectious disease of the respiratory system or because of another type of infection. This finding cannot be explained away with the argument that the infection had caused cholesterol to go down, because how could low cholesterol, recorded when these people had no evidence of infection, be caused by a disease they had not yet encountered? Isn´t it much more likely that low cholesterol in some way made them more vulnerable to infection, or that high cholesterol protected those who did not become infected. Much evidence exists to support that interpretation.

Heart disease may lead to a weakening of the heart muscle. A weak heart means that less blood and therefore less oxygen is delivered to the arteries. To compensate for the decreased power, the heart beat goes up, but in severe heart failure, this is not sufficient. Such patients become short of breath because too little oxygen is delivered to the tissues, the pressure in their veins increases because the heart cannot deliver the blood away from the heart with sufficient power, and they become edematous, meaning that fluid accumulates in the legs and in serious cases also in the lungs and other parts of the body. This condition is called congestive or chronic heart failure.

There are many indications that bacteria or other microorganisms play an important role in chronic heart failure, and also that the risk of heart failure is much greater in people with low cholesterol.

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