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Not All Cholesterol-Reducing Supplements Are Equal

From garlic to guggulsterone, fish oil to policosanol, substances aimed at reducing cholesterol are among the best-selling dietary supplements. But a new evaluation shows some products don't measure up to their labels or marketing claims.

ConsumerLab.com reviewed the body of scientific evidence behind each cholesterol-lowering supplement. The company also tested specific products for quality standards.

Cloud over Policosanol

All of the policosanol products tested in the evaluation contained proper doses of the active ingredients. But new research suggests that the supplement may not be effective in lowering cholesterol.

Policosanol is made from plants, most often sugarcane. Many studies from Cuba, where it's produced, have shown that it can lower low-density lipoproteins (LDL), or unhealthy cholesterol.

But a recent German study published in the Journal of the American Medical Association found policosonal was no more effective than a placebo.

Strong Evidence Behind Plant Sterols

ConsumerLab.com's evaluation concludes there's strong evidence that plant sterols can decrease LDL by 10 percent to 15 percent. They do not affect high-density lipoproteins (HDL), the so-called good cholesterol. Sterols are sold in supplement form, as well as in buttery spreads such as Benecol. They work by eliminating cholesterol that the liver recycles through the gut, and also help reduce the absorption of dietary cholesterol.

One product, called Carlson Right for Cholesterol, failed the test because it wouldn't dissolve.

"If you put this tablet in your stomach it just sits there and doesn't release its ingredients," says Tod Cooperman of ConsumerLab.com

The company that manufacturers the product, Carlson Nutritional Supplements, says it's looking into the matter. A company spokeswoman says one original test of the product showed that the product did break apart properly.

Quality Varies Greatly

Physician Wendy Biggs, who's in family practice in Michigan, says she counsels patients to know more about the supplements they're taking. There aren't always a lot of studies to back up claims made by supplement makers.

But the latest review -- as well as a new comprehensive database on dietary supplements produced by Consumer Reports -- is a good resource.

Supplements May Not Be Enough

Lowering your cholesterol to the recommended target has been shown to reduce the risk of heart attack and stroke. Knowing your starting cholesterol is important in determining which supplement may benefit you.

Candy Tsourounis, a pharmacy professor at the University of California, San Francisco, says people should be tested so they have an accurate count of HDL, LDL and total cholesterol to work with.

"If you know you need to lower cholesterol by 30 points, choosing a supplement that only lowers it by 10 points won't get you to the goal," says Tsourounis.

This is significant because getting cholesterol down to a recommended target is what's been shown to reduce the risk of heart attack and stroke.

Copyright 2022 NPR. To see more, visit https://www.npr.org.

Allison Aubrey is a correspondent for NPR News, where her stories can be heard on Morning Edition and All Things Considered. She's also a contributor to the PBS NewsHour and is one of the hosts of NPR's Life Kit.