Natural ways to keep colds at bay

Q: I'm a competitive skier, and this is a big year for me. I am nervous about catching a cold, which sometimes knocks me down for weeks. Is there anything natural I can take to prevent getting one?

A: The most important step you can take to prevent a cold is to wash your hands, especially after contact with someone who is sick. Ideally, wash hands for at least 20 seconds with plain soap. Because colds are caused by viruses, not bacteria, antibacterial soap is not necessary. Alcohol-based hand rubs also work if you don't have access to a sink.

There is much less research on preventing colds with natural remedies than on treating colds with them. (We will discuss the treatment of colds with natural remedies next week.)

Here are some of the more-common supplements people use to prevent colds, with varying degrees of success:

• Garlic. One study found that people who took a garlic supplement with allicin reduced their number of colds by more than 50 percent.

Allicin is one of the active ingredients in garlic, which is synthesized when you cut or crush a clove. Most supplements have very little allicin in them; the product used in the study, Allimax, patented a process to obtain higher levels of allicin. The caveat is that several participants noticed a garlic odor, which some people may not like.

• Echinacea. Four studies have shown that echinacea extracts do not work to prevent colds, though the data on treatment are more controversial.

• Goldenseal. There is no research to support using goldenseal for colds. In addition, this little woodland plant is endangered, and hard to grow. Overharvesting contributes to the loss of ecological diversity on our planet; it also means that goldenseal is much more likely to be adulterated in supplements.

• Lactobacillus GG. This is a beneficial bacteria, otherwise known as a "probiotic," which is naturally found in the colon. One peer-reviewed study found that children in day care who received milk with Lactobacillus GG had fewer, less-severe colds than those who didn't.

Lactobacillus GG is a patented strain of Lactobacillus rhamnosus, which is found only in the product "Culturelle." Other types of Lactobacillus, like acidophillus or reuteri, have health benefits, but we don't know whether they specifically help prevent colds.

Dr. Pujari is a Seattle M.D. with an additional degree as a medical herbalist; she practices at the Pujari Center and teaches as part of the residency programs at Virginia Mason and Swedish Providence hospitals. Her column is a weekly feature in Sunday Northwest Life. Send questions to apujari@seattletimes.com for possible use in future columns.