Low Cholesterol Levels May Signal the Beginning of Colon Cancer

In the early 2000's, and periodically since, there were proposals from the medical profession that the entire world should be put on statin medications, the drugs most commonly prescribed to lower cholesterol. Physicians writing in BMJ, the British Medical Journal, even proposed that a polypill consisting of a statin like Lipitor, three blood pressure drugs (including one known to increase the risk of diabetes), folic acid (which is harmful to the 22 percent of the population who have what are called MTHFR mutations), and Aspirin should even be added to the water supply, like fluoride. The combination, the experts opined, could eliminate 80 percent of heart attacks. 

Actually, for some people the combination actually causes heart attacks, but fortunately for the world, the overzealous advocates of anti-cholesterol medications haven't got their way. Recently researchers uncovered at least one reason against willy-nilly prescription of statins, increased risk of colon cancer. However, like nearly any study, this study also has results that need to be understood in terms of nuance.

Cholesterol and the Danger of Being Diagnosed with Colon Cancer in the Next Year

One of the medical miracles attributed to long-term use of Lipitor, Crestor, Zocor, Mevacor, and other statin drugs is reduced risk of colon cancer, but group of researchers at the University of Pennsylvania, Yale, and Tel Aviv University has found a wrinkle in the results of a study of cholesterol levels and colon cancer.

Basically, the findings of the research are these:

• People who take statins are less likely to be diagnosed with colon cancer.
• People who have sharp drops in cholesterol levels are more likely to be diagnosed with colon cancer.

These two findings look contradictory, don't they? They looked contradictory to the researchers, too. This group of doctors looked at the possibility that a systematic bias in favor of statin drugs led other researchers to conclude that statins reduce colorectal cancer risk. Here's how they teased out answers from the masses of data.

Statins Decrease Your Risk of Colon Cancer, But...

The researchers analyzed 22,163 colorectal cancer cases and 86,538 matched controls from a supposedly randomized database called The Health Improvement Network (THIN). They found that using a statin reduced the risk of colon cancer by about 5 percent. That figure, however, is a little misleading. Everybody doesn't get colon cancer. Even if you live in one of the most colon cancer-prone countries on earth, your risk of getting colon cancer in any given year is only about 4 in 1000. If you take a statin drug, your risk of colon cancer is 5 percent less, which is still about 4 in 1000.

READ Statins, Cholesterol-Lowering Class of Drugs, Lower Male Sex Drive, Too

However, when the researchers looked at the data for the 24,132 who said "Enough statins, I'm not taking any more," or whose doctors took them off the drugs, they found that lower cholesterol was associated with higher rates of colon cancer. For every 1 mmol/L (38 mg/dl) people lowered their cholesterol with statins, they had a 25 percent greater risk of cancer. For every 1 mmol/L (38 mg/dl) lowering of cholesterol without statins, risk of colon cancer more than doubled.

Will Taking Statins Cause Colon Cancer?

To be fair, if your risk of developing colon cancer in any given year is 4 in 1000 and it goes up by 25 percent because you take a statin, it's still just 5 in 1000. If the risk more than doubles (in this study, the ratio was 2.53 to 1), then your risk of getting colon cancer in the next year, without taking any other factors into account, is still just 1 in 100. The information in this study is much more important for policy makers, who are concerned about whether there are 10,000 cases needing treatment next year or maybe there will be 20,000, but it's not terribly significant to you. Statin side effects, on the other hand, don't worry policy makers but can be a huge problem for you. The bottom line for individuals simply trying to lead healthy lives is:

Doctors get hung up on the fact that statins seem to do a number of great things and they lower cholesterol, so the thing to do is give you more and more and stronger and stronger statins to lower your cholesterol. Don't take Lipitor, take Crestor. Don't take 10 mg, take 40 mg. If there were just some way to get you to a negative cholesterol number, you'd live forever. This is an example of what researchers call indication bias.

Cholesterol researcher is riddled with indication bias. The fundamental problem in a lot of the research is that researchers assume there is a direct relationship between cholesterol and a health outcome, when in fact there are many intermediate steps.

Take the example of cholesterol and heart disease. Yes, there is cholesterol in the plaques that can "harden" arteries. But that's not all that is in these plaques, and plaques are not the only factor in a heart attack or congestive heart failure. First cholesterol gets deposited in the lining of an artery. Then a white blood cell comes along to use it as fuel and gets stuck. Then the white blood cell dies and other white blood cells come along to remove it. They also get stuck. They die. They calcify. The entire mass hardens. If a blood clot forms, then the artery can't expand enough to let it pass, or maybe it can. If the blood clot impedes circulation, then heart tissue may die, or not, if oxygen is returned to the heart slowly enough. The whole idea that taking a statin just to lower cholesterol reduces risk of heart disease lacks a nuanced understanding of the process.

READ Evidence That Statins Stimulate Atherosclocrosis And Heart Failure

However, if your doctor only has five minutes for you and some reviewer will certainly ask why you aren't on a statin drug, then you are going to get a statin drug. Just don't be afraid to ask questions about why you really need a statin drug, and if you have a family history of colon cancer, ask your doctor if a statin to reduce cholesterol levels is really right for you.