Subjects in a small Pennsylvania study who took red yeast rice showed a significant decrease in both their total and LDL (bad) cholesterol. This isn't the first study to show this effect. This particular study was on subjects who had stopped taking statins, the most commonly prescribed cholesterol lowering drugs, because of their side effects. The side effects seen in this study were minimal.

It's what gives Peking duck its distinctive coloration.

But don't expect to see red yeast rice commonly used as a cholesterol lowering substance anytime soon in the U.S. There's way too much controversy surrounding it.

Red yeast rice is produced by growing a red yeast (Monascus purpureus) on rice. It has been used as a food, food coloring and medicine in some Asian cultures for over a thousand years. It's what gives Peking duck its distinctive coloration.

Statins are the most commonly prescribed medication to control cholesterol. Some people who take statins experience serious side effects, mainly muscle pain and weakness. Statins can also cause liver problems. The subjects in the Pennsylvania study were all people who had experienced these side effects and stopped taking statins. Half of the group of 62 took 1,800 milligrams of a red yeast rice preparation twice daily for 24 weeks. The other half received an inactive substance or placebo. All subjects followed a lifestyle change program.

At 12 weeks, the red yeast rice group showed a drop in LDL cholesterol 31 points greater than that of the group receiving the placebo. At 24 weeks, this difference had shrunk to about 20 points. The researchers speculate that this may have been due to some participants stopping the treatment. Regardless, a 20 point drop in LDL cholesterol is still significant.

So why is this treatment unlikely to be common soon? The issue is mainly whether red yeast rice is a supplement or an unregulated drug.

Lovastatin was the first statin marketed in the U.S. and is still prescribed as a cholesterol lowering medication today. Red yeast rice contains lovastatin. In the Pennsylvania trial, this amounted to about six milligrams per participant per day. This is not enough to account for the subjects' drop in cholesterol by itself; the commonly prescribed starting dose of lovastatin is 20 milligrams per day and the smallest lovastatin pills manufactured contain 10 milligrams. In 1998, the FDA declared preparations of red yeast rice containing more than a trace amount of lovastatin to be illegal. The stated reason was that lovastatin content made red yeast rice an unregulated drug, not a dietary supplement. A district court in Utah ruled that the FDA decision was illegal. In 2000, an appeals court overturned this ruling, ruling in favor of the FDA. So, red yeast rice is currently classed as a drug. Any red yeast rice now sold in the U.S. is either made using a process that does not produce lovastatin or has had its lovastatin removed. Supposedly. It is nearly impossible to tell what is and isn't present in a randomly purchased red yeast rice preparation without having it analyzed.

In addition to lovastatin, red yeast rice contains several compounds called monacolins that are chemically related to statins. Any or all of them might be responsible for the cholesterol lowering effect. Why didn't these show the side effects of known statins in the Pennsylvania study? Perhaps they're better statins. Or possibly the cholesterol lowering effect comes from other unknown compounds. This simply is not known at present. It will take fewer fistfights and more research to answer these questions.

So what does this all add up to? Red yeast rice is a natural product that has been shown in many studies to be effective at lowering cholesterol. How it works exactly isn't known, nor is it clear who in the U.S. should be regulating it or what currently available preparations sold in the U.S. actually contain. If these questions are ever answered, it's possible that an effective anti-cholesterol treatment may emerge.

The results of the Pennsylvania study were published in the June 16, 2009 issue of the Annals of Internal Medicine.