Antioxidants, Drugs Battle It Out Against Heart Disease

From the WebMD Archives

Nov. 28, 2001 -- Cholesterol-lowering drugs and antioxidants have been battling it out to see who reigns supreme in the fight against heart disease. But findings raise a serious concern about antioxidants.

Drugs that lower cholesterol are known to help keep heart disease at bay by preventing blockage in arteries. But antioxidants are thought to have some benefit as well. So researchers wanted to see if giving it the old one-two punch might be the best approach.

Cholesterol can be a tricky thing to understand when it comes to heart disease. You take the good, you take the bad, you take them both, and there you have the facts of heart disease.

LDL cholesterol is the bad guy. High levels of LDL increase the chance that you'll develop heart disease. In order to improve your fight against heart disease, your LDL should be less than 100, according to cholesterol guidelines released earlier this year. But once your LDL creeps over 130, you are getting into the borderline high range. At 160, you've gone over the edge.

But there's a good guy in this story, too. Higher levels of HDL cholesterol can actually help prevent heart disease and blocked arteries. Optimal levels of HDL are 60 and up. If your HDL is at least 40, then you're doing OK, but lower than this and you need to talk to your doctor about how to bring it up.

B. Greg Brown, MD, PhD, and colleagues put cholesterol-lowering drugs and antioxidants to the test. Brown is with the department of medicine at the University of Washington in Seattle.

Would drugs or antioxidants alone improve cholesterol? Would using both of them together do even better?

The researchers looked at 160 people who had heart disease as well as high LDL cholesterol levels and low HDL. People took antioxidants alone, cholesterol-lowering drugs alone, or both. They also compared these results to people taking a placebo.

The antioxidants consisted of 800 IU of vitamin E, 1,000 mg of vitamin C, 25 mg of natural beta-carotene, and 100 micrograms of selenium.

Continued

The cholesterol-lowering drugs that were used were Zocor and niacin. Zocor belongs to a class of drugs called "statins," which also include Lipitor and Pravachol.

The researchers found that antioxidants had no effect on cholesterol levels when taken alone. However, Zocor and niacin together improved cholesterol significantly. LDL fell 42% while HDL rose 26%.

The results of the study are published in the Nov. 29 issue of The New England Journal of Medicine.

The researchers then looked at each person's blood vessels in the heart to see how much blockage there was -- keeping in mind that each participant in the study was already known to have heart disease.

Antioxidants were no better than placebo at stopping the progression of heart disease. However, the cholesterol-lowering drugs were able to actually lessen the blockage.

And in a surprising, yet concerning, finding, the researchers found that when antioxidants were added to cholesterol-lowering drugs, not only did the blockage not improve, but it actually continued to worsen.

The next step was to see if the different treatments actually led to different results -- and they did.

The researchers looked at the number of people who, over the three-year study, suffered a heart attack, stroke, or required another procedure to open blocked arteries.

While about 21%-24% of those taking antioxidants or placebo experienced further problems, just 3% of the people taking Zocor and niacin suffered the same fate.

And again, when antioxidants were added to the drugs, things didn't go as well -- with 14% of them having a heart attack or stroke.

The researchers were able to pinpoint one possible reason why antioxidants might actually be harmful in the prevention of heart disease. The antioxidants lowered the amount of one type of HDL cholesterol. And while the drugs improved HDL cholesterol when used alone, when the antioxidants were added, the benefit was less.

The researchers say that unless more compelling evidence comes along in support of antioxidants, they see little reason to use them -- especially since they might actually make things worse.

But Jane E. Freeman, MD, points out that the findings, although intriguing, might not be relevant to people who don't already have heart disease. In other words, the possibility still exists that antioxidants might be helpful in preventing heart disease in healthy people. Freeman, who wrote an editorial accompanying the study, is from Boston University School of Medicine.

Continued

Stay tuned, and hopefully future research will reveal all the facts behind antioxidants and heart disease.

WebMD Health News
© 2001 WebMD, Inc. All rights reserved.

Pagination