What it's supposed to do: It's typically used in conjunction with glucosamine, primarily to help treat pain and swelling in people with osteoarthritis. It may replace a different material in cartilage than glucosamine does, but whether this is truly happening is subject to debate, according to Rindfleisch. Because the supplement is sometimes made from parts of a cow, some people were worried that taking the supplement might theoretically increase their risk for mad cow disease.
What research suggests: Right now, the research on chondroitin for osteoarthritis is even less convincing than it is for glucosamine, suggested Rindfleisch.
Bottom line: The typical daily dose of chondroitin sulfate is 1,000 to 1,200 milligrams, often taken as 400 milligrams three times a day. If you decide to try it, use it together with the supplement, glucosamine sulfate.
What it is: Allicin, a component of whole garlic and believed to be the medically active ingredient in the clove, is placed into supplement form.
What it's supposed to do: From a cardiac standpoint, garlic has been thought to help lower total cholesterol, and LDL cholesterol, in particular, said Guarneri, who is a cardiologist. People who consume more garlic in their diet may reduce their risk for stomach and colorectal cancers. Supplements of the fragrant bulb have also been suggested for reducing high blood pressure and for treating infections.
What research suggests: There's no research that it can improve cardiovascular outcomes or decrease cholesterol, noted Guarneri. "As a matter of fact, there are negative studies." The evidence for some cholesterol-lowering benefit seems to come from short-term studies of 4 to 12 weeks in length. Data on the herb's ability to reduce blood pressure suggests only a modest reduction.
Bottom line: "Garlic may be something that people can use for other reasons, such as an infection or a sore throat, but I've not seen a benefit from it for cholesterol," concluded Guarneri. She said garlic is not her first choice of supplements to help lower cholesterol; she prefers, instead, to recommend red yeast rice.
What it is: Also known as CoQ10 or ubiquinone, this substance is normally produced by the body and is a necessary cofactor in the production of energy by cells.
What it's supposed to do: Low levels of CoQ10 have been reported in patients with Parkinson's disease, congestive heart failure, and those taking statin drugs to reduce cholesterol. Guarneri believes that "it's a necessary agent in protecting against statin-induced myopathy, a type of muscle ache and weakness that can be a side effect of taking the drug in some people. She also thinks 1,200 milligrams of it a day can be beneficial in people who have symptoms of Parkinson's disease, and it could be helpful for people who have muscle weakness.
What research suggests: "There's strong research that CoQ10 is an independent predictor of mortality in chronic heart failure," pointed out Guarneri. CoQ10 works on the mitochondria in cells, where energy is produced. There's good evidence that if levels are deficient, supplementation can be effective.
Bottom line: "It's an excellent cofactor for supporting the energy of the cell," advised Guarneri, who recommends it to all of her patients on statin drug therapy and those who have congestive heart failure.
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