Health Answers

Do garlic supplements reduce the risk of the common cold?

By Judy Foreman
September 21, 2009

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Q. Do garlic supplements reduce the risk of the common cold?

A. Maybe. Australian researchers combed the literature and found only one study with good enough methodology to evaluate. The team, from the University of Western Australia, published its findings online in the July issue of the Cochrane Collaboration, an international nonprofit that analyzes health care information.

That study, in which 146 participants were randomly assigned to take a daily garlic supplement or a placebo, found that those taking the supplement got fewer colds over the three-month study period than those taking the dummy supplement. They also got over their colds faster.

Even the authors, in the article and in e-mail interviews, said that this evidence is too slim to make firm recommendations about garlic’s effectiveness.

“My advice is that if you feel it is helpful, go ahead and use it,’’ said Dr. J. Owen Hendley, an infectious disease specialist at the University of Virginia School of Medicine who studies the common cold.

If garlic is useful for the common cold, said Dr. Kimon Zachary, an infectious disease specialist at Massachusetts General Hospital, it’s probably more effective as a preventive than as a treatment once a person has a cold.

There are few risks to taking a garlic supplement. Garlic can interfere with an anti-HIV medication called saquinavir and can reduce the ability of the blood to clot, a potential concern for surgical patients, according to the National Center for Complementary and Alternative Medicine.

But while more research is needed, the Cochrane analysis shows that “you can’t dismiss garlic as a potential preventive’’ for colds, said Mark Blumenthal, executive director of the American Botanical Council, a nonprofit group that is partially supported by the herbal products industry.

Since garlic may have other health benefits as well - the research is still evolving - I figure, why not take it to ward off colds as well? At the very least, the smell might keep germy people away!

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