Defeat Cold and Flu Bugs

Create a winning game plan with herbs that boost your defenses.


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Cold and flu season will soon be upon us, the time when those who use medicinal herbs stock up on the two most popular non-pharmaceutical cold remedies — vitamin C and echinacea. Both are effective cold treatments, but neither work all that well for prevention, and they’re far from the whole story. However, if you understand how the immune system defends against colds and how the pesky infection spreads, you may be able to remain cold-free while those around you are congested and coughing. And if you catch a cold, expanding your horizons beyond vitamin C and echinacea can limit your misery and speed your recovery.

Colds are humanity’s most common illness. They’re caused by some 200 viruses that infect cells at the junction of the nose and throat (nasopharynx). Technically, each virus causes a different cold, but because all colds produce similar symptoms, we consider the common cold a single illness.

Most colds start with a scratchy throat and progress through nasal congestion and runny nose to a dry, hacking cough. In adults, colds rarely cause fever (unlike flu — see “Beat the Flu with a Flu Shot” on Page 26). Medically, colds are minor and “self-limiting,” meaning they go away even if you don’t treat them, usually within a week.

But the misery colds cause feels anything but minor. Americans now suffer some 500 million colds each year and spend $17 billion a year to treat them. Most of that money is wasted on pharmaceutical cold formulas that merely suppress cold symptoms without speeding your recovery. If you really want fast relief, non-drug approaches — including several herbs — are the way to go.

Key to Prevention: A Strong Immune System

Americans tend to be fatalistic about colds. But considerable research shows that by bolstering the immune system, risk can be reduced significantly.

Get regular, moderate exercise. Exercise boosts immune function and helps prevent colds, according to researchers at Appalachian State University in Boone, North Carolina. But don’t overdo it: Strenuous exercise lasting longer than 90 minutes suppresses immune function, increasing the risk of colds.

Manage your stress. Ever catch a cold while studying for finals? Blame stress. At Carnegie Mellon University in Pittsburgh, Sheldon Cohen, Ph.D., used psychological tests to gauge stress levels in 400 volunteers. Then he exposed them to live cold viruses. Compared with the least-stressed folks, the most stressed were almost twice as likely to catch the cold. Stress impairs cold-fighting immune function. To manage stress, try meditation, listening to music and doing yoga, tai chi and other forms of moderate exercise.

Be sociable. Colds spread from person to person, so you’d think that loners would catch the fewest. Actually, it’s the other way around: As social connections increase, risk of colds decreases. That’s what Pittsburgh’s Dr. Cohen discovered in a study of 334 volunteers who completed surveys of their social ties and then were exposed to cold viruses. Apparently, the immune boost gained from being sociable more than compensates for the increased risk of spending time around those who have colds.

Make love. Speaking of sociability, moderate physical intimacy also is protective. Researchers at Wilkes-Barre University in Pennsylvania surveyed 112 college students about their sexual frequency and then analyzed their saliva for immunoglobulin A (IgA), one of the body’s first defenses against colds. Those who reported making love once or twice a week had IgA levels higher than those who made love less, or more.

Appreciate your colds. Recovery from colds confers several years of immunity to that specific virus. Adults have a good deal of this immunity stored up from years of fighting colds. Young children don’t, which is one reason they catch so many colds.

Break the Chain of Transmission

Colds spread in two ways — through the air and by direct contact. When cold sufferers exhale, cough or sneeze, they spew virus particles into the air. The uninfected inhale them and often catch the cold.

“Direct contact” means transmission from the fingers to the nose or eyes. People unconsciously touch their noses and eyes several times an hour. When you have a cold, nose-touching contaminates your fingers with virus. If you touch other peoples’ hands or hard surfaces — counters, doorknobs, telephones, etc. — you deposit virus particles that can survive for several hours. The uninfected literally pick the virus up on their fingertips, touch their noses and get infected. They also might rub their eyes.

To break the chain of transmission, practice the following:

If you have a cold, call in sick. Many cold sufferers insist on going to work, school or other activities and many employers don’t provide adequate leave for sick workers, or don’t offer paid sick days. This greatly increases the risk of infecting everyone in your workplace. If at all possible, stay home for a day or two.

Keep your fingers away from your nose and eyes. This prevents direct-contact transmission. Oddly, this is not as easy as it sounds. If a cold is going around, rub your nose or eyes with a knuckle instead of a possibly contaminated fingertip.

Wash your hands. This prevents direct-contact transmission. At one daycare center, Purdue University researchers taught children, aged 3 to 5, to wash their hands often to prevent colds. Kids at

another daycare center received no hand-washing instruction. During the winter cold and flu season, the kids who washed their hands frequently caught significantly fewer colds.

Use disinfectant on household surfaces. Cold viruses can survive up to several hours on counters, telephone handsets and other hard surfaces. But disinfectants kill them. At the University of Ottawa, Canada, researchers contaminated stainless-steel surfaces with cold virus, then sprayed them with Lysol or wiped them with bleach. Both treatments killed more than 99.5 percent of the cold viruses.

Retire cloth hankies. Live virus can survive for several hours in cloth hankies. Every time you pull them out, you re-contaminate your fingers. Switch to disposable facial tissues. Use them once, then discard them. Afterward, wash your hands.

As Mom and Miss Manners would remind you, cover your mouth when you cough and sneeze. This limits the number of virus particles you release into the air. Wash your hands afterward.

Treat Colds Herbally

Use echinacea to treat colds, not prevent them.

For all of these herbs, follow package directions for dosage.

Echinacea (Echinacea spp.). The past few years have not been kind to everyone’s favorite cold herb. Since 2002, two published studies have shown that echinacea provides no treatment benefit for colds — one in the Journal of the American Medical Association attracted considerable media attention. But with all due respect, these findings contradict a great deal of previous research.

For example, in 1999, University of Wisconsin researchers analyzed 12 studies of echinacea for cold prevention and treatment. All eight of the treatment studies showed that echinacea provides significant benefit. Compared with untreated cold sufferers, those taking the herb had symptoms only half as severe and felt ill fewer days. In a more recent study, researchers at York College in Pennsylvania gave 95 people with early colds either a placebo or the herb (Echinacea Plus tea by Traditional Medicinals, five cups a day). The echinacea group reported briefer, milder colds.

The two recent negative studies are disappointing, but they don’t negate the nine studies showing the herb beneficial. I still use echinacea and I think it helps.

But echinacea doesn’t do much to prevent colds. In the Wisconsin analysis (above), none of four studies showed preventive value. Use echinacea to treat colds, but if you take it for prevention, you’re wasting your money.

Echinacea is safe for children with colds, says Linda White, M.D., coauthor of Kids, Herbs, & Health (Interweave, 1998). If your echinacea label does not specify a dosage for kids, use your child’s weight to calculate the dose. Adult doses are based on a person weighing approximately 150 pounds. If your child weighs 50 pounds, use one-third of the adult dose.

Andrographis (Andrographis paniculata). Andrographis is quickly becoming the new echinacea for colds. Native to India, China and Southeast Asia, this annual herb has a long history in traditional Chinese and Ayurvedic medicines as a treatment for fever. In the past few years, it has come on strong as a cold treatment.

At the University of Chile in Santiago, researchers gave 158 adults coming down with colds either a placebo or andrographis (1,200 mg a day). By day two, the andrographis group reported milder sore throat and less runny nose. By day four, the andrographis group reported significant relief of all symptoms, with no side effects. Last year, researchers at the University of Exeter in the United Kingdom analyzed seven studies of andrographis for colds. They found significant benefit.

Slippery elm bark (Ulmus rubra) and licorice root (Glycyrrhiza glabra). For the sore throat at the start of a cold, a tea of these two herbs provides remarkable relief. Wisconsin researchers gave 60 sore throat sufferers a placebo or a commercial tea containing elm bark and licorice (Throat Coat from Traditional Medicinals). The tea provided significantly greater relief.

Ashwaganda (Withania somnifera), ginseng (Panax ginseng, P. quinquefolius) and reishi mushroom (Ganoderma lucidum). There are no studies showing that these herbs prevent or treat the common cold. But ginseng boosts the effectiveness of flu shots (see “Beat the Flu with a Flu Shot” on Page 26), and all three are safe immune stimulants, so it’s a good bet that they would bolster the body’s defenses against colds.

Hot herbal teas. Grandma was right about hot liquids. Cold viruses reproduce best at temperatures slightly below normal body temperature. Any hot herb tea warms the throat, impairing viral replication. Hot liquids also help soothe a sore throat, suppress cough and have a mild decongestant effect.

Other Helpful Nondrug Treatments

Try chicken soup — or vegetable soup. Chicken soup has been a folk cold treatment for centuries. In a famous study, Florida researchers showed that chicken soup does, indeed, relieve nasal congestion better than plain hot water. And University of Nebraska cold research confirmed chicken soup significantly reduced throat-cell inflammation. Surprisingly, the Nebraska group’s soup worked even before the chicken was added, when it was simply onion-rich vegetable soup. Many studies have shown that vegetables, notably onions, have anti-inflammatory action. Onions are close botanical relatives of the antiviral herb garlic.

Take enough vitamin C. Since 1970, when the late Nobel laureate Linus Pauling published Vitamin C and the Common Cold, this nutrient has ranked among the nation’s most popular — and most controversial — cold remedies. Some studies have shown preventive benefit, others have not. Some have shown treatment success, others have not.

Scientific controversy continues to rage, but the best current evidence is that vitamin C has modest preventive value and considerable — but not miraculous — value as a cold treatment. An Australian analysis of 29 studies shows that vitamin C significantly reduces the severity and duration of colds.

What about the studies showing no benefit for vitamin C? In general, they used too little of the vitamin for too short a time. You need at least 2,000 mg a day from the first throat tickle until the cold is gone.

Think zinc. Over the past 20 years, a dozen studies have tested zinc gluconate or zinc aspartate lozenges against colds. Most — including one trial of Cold-Eeze brand of lozenges — have shown that the mineral produces significantly shorter and milder colds. The effective dose ranges from 13 to 23 mg of zinc every two waking hours, from the first inkling of a scratchy throat until the cold is gone. The studies showing no benefit have generally used less than 13 mg of zinc for briefer periods. Note: Zinc makes some people queasy. If that happens to you, discontinue use.

San Francisco-based health writer Michael Castleman is the author of 11 consumer health books, including Cold Cures: The Complete Guide to Preventing and Treating the Common Cold and Flu. Visit his website at