In from the cold: do supplements work? (Cover Story).

You've got a cold. Your nose is running. You're stuffed up. Your head aches.

You could tough it out. If you don't do anything, you'll probably be back to normal within a week. Or you could take something.

If you do, you won't be alone. Americans spend some $3 billion a year on preparations to ward off colds or treat their symptoms. And we pop supplements that claim to "boost" or "support" the immune system like there's no tomorrow.

What are we getting for our money? In many cases, more hype than healing.

Millions of Americans swear by vitamin C, zinc, echinacea, or other preparations to help prevent or treat their colds or to shore up their immune systems. Should you? It all depends on what you take ... and when you take it. Here's the evidence on five of the most popular supplements.

ZINC

In test tubes, zinc slows the growth of rhinoviruses, which cause about a third of all colds. In people, cold viruses grow mostly in the nose, and the mouth isn't far away. That may explain why sucking on zinc lozenges seems to cut colds short.

In five studies, people who started taking zinc gluconate lozenges every few hours after their first sneeze were sick for one to three fewer days than people who took a placebo. (1-5) Several of the studies used Cold-Eeze lozenges and were funded by Cold-Eeze's manufacturer (the studies were well-designed).

And in two other studies, volunteers who took zinc acetate lozenges as soon as they felt sick got over their colds up to three days faster than those who were given a placebo. (6,7)

Adverse Effects

Researchers haven't looked at whether taking zinc pills can prevent or shorten colds. And there's good reason not to do the research on yourself. Getting more than 40 milligrams a day of zinc (from supplements and food combined) for an extended period can weaken your body's antioxidant defenses, lower your HDL ("good") cholesterol, and make your immune system less able to fight off disease.

It's not difficult to get 40 mg, which is the Tolerable Upper Intake Level (UL) set by the National Academy of Sciences. If you take a multivitamin, you're probably getting 15 mg (that's the U.S. Recommended Daily Allowance, also called the Daily Value). That bowl of Total cereal? You can add another 15 mg. And if you take zinc pills, you could be over 40 mg before you head out the door in the morning. (Sucking on more than 40 mg a day of zinc lozenges while you have a cold shouldn't pose any problems.)

If You Take Zinc

If you want to try what worked best in the studies:

* Stick to lozenges that contain zinc gluconate or zinc acetate.

* Start taking the lozenges at the first sign of a cold.

* Make sure the product doesn't contain any vitamin C (ascorbic acid), citric or tartaric acid, or the sweeteners mannitol or sorbitol. Those ingredients may bind the zinc, which means that less is available to fight your cold.

* Stop taking the lozenges as soon as your cold is over.

* Talk to your doctor if you're on the antibiotic tetracycline or one of the fluoroquinolone antibiotics (like Cipro). Too much zinc can make it harder to absorb the drugs.

The Bottom Line: Sucking on zinc gluconate or zinc acetate lozenges at the first sign of a cold may help cut it short.

(1) Antimicrobial Agents and Chemotherapy 25: 20, 1984.

(2) Journal of Antimicrobial Chemotherapy 20: 893, 1987.

(3) The Journal of International Medical Research 20: 234, 1992.

(4) Annals of Internal Medicine 125: 81, 1996.

(5) Clinical Infectious Diseases 31: 1202, 2000.

(6) Annals of Internal Medicine 133: 245, 2000.

(7) Current Therapeutic Research 59: 595, 1998.

ECHINACEA

In theory, echinacea should help fight colds. In some animal studies, it stimulates natural killer cells and monocytes, which the immune system uses to fight off viruses.

And in more than half the human studies that looked, the herb either slashed a couple of days off the typical cold or cut down on the coughing, runny nose, and other symptoms.

For example, in a study of 95 Pennsylvania residents, those who started drinking Echinacea Plus Tea at the first sniffle had colds that ended about two days sooner than the colds of those who drank echinacea-free tea. (1) (Both groups drank five cups the first day, four cups the second day, three cups the third day, two cups the fourth day, and one cup the fifth day, even if they no longer had a cold.)

And in a study of 119 cold-sufferers in Sweden, those who took two Echinaforce pills three times a day for a week experienced slightly greater relief of symptoms like fever, runny nose, and coughing than those who took a look-alike (but echinacea-free) placebo. (2)

Yet some researchers are not convinced that echinacea works. In a few studies it failed to shorten colds. In a few others, symptoms improved only slightly.

Then there's the taste, which is almost impossible to mask. Unfortunately, when most of the echinacea studies were over, the researchers didn't ask the volunteers whether they thought they had been taking the herb or the placebo. So it's possible that people taking echinacea felt better because they expected to.

And there's the question of what to test. Echinacea supplements contain one or more of the three species that Native-American healers traditionally used: E. purpurea, E. pallida, and E. angustifolia. Most successful studies used at least some E. purpurea, so that's your best bet.

But you can't always tell how much of what you're getting. Some companies combine species. Some use extracts. Some just grind up the leaves. A few "standardize" their products to contain a minimum level of phenolic compounds, which some researchers think are echinacea's active ingredients. And you can find echinacea--often in unknown quantities--in tea bags, juices, and even lollipops and gummi bears for kids.

If that encourages you to take echinacea (or give it to your child) to prevent a cold, you could be wasting your money. Studies consistently find that the herb doesn't seem to ward off colds.

In one of the largest, the 200 volunteers who took echinacea for 12 weeks were as likely to come down with a respiratory infection as the 100 who took a placebo. (3) And when researchers gave people echinacea or a placebo for two weeks before exposing them to rhinovirus, the echinacea group was just as likely to get sick--and to be just as sick--as the placebo group. (4)

But there's a more compelling reason to not take echinacea when you don't need it.

Adverse Effects

"After eight weeks, echinacea can switch from stimulating the immune system to suppressing it, at least in animals," says Chun-Su Yuan of the Tang Center for Herbal Medicine Research at the University of Chicago. It's not clear if that means that people who take echinacea for months at a time could be more susceptible to colds and other infections.

What's more, like with most other herbs, there are no published long-term studies (in animals or people) testing whether echinacea causes other problems.

Check with your doctor before taking echinacea if you are:

* Allergic to plants in the same family (ragweed, daisies, sunflowers, chrysanthemums, and asters), even though reported reactions are rare.

* Breastfeeding, pregnant, or trying to conceive. (The only study that looked at women who took echinacea while pregnant found no problems, but without more studies in people and animals, it's too early to call echinacea safe.)

* Suffering from an autoimmune disease like lupus or rheumatoid arthritis. Stimulating the immune system could cause flare-ups.

* Taking drugs to suppress the immune system.

* Suffering from HIV/AIDS. There's not enough research to tell whether echinacea helps or hurts.

The Bottom Line: Echinacea may help lessen the symptoms of your cold. If you try it, look for a preparation that contains E. purpurea, and start taking it as soon as your cold hits.

(1) Journal of Alternative and Complementary Medicine 6: 327, 2000.

(2) Phytomedicine 6: 1, 1999.

(3) Archives of Family Medicine 7: 541, 1998.

(4) Antimicrobial Agents and Chemotherapy 44: 1708, 2000.

VITAMIN C

Millions of people swear that popping extra vitamin C helps stave off colds. Are they fooling themselves?

"The published studies indicate that regular high-dose vitamin C supplementation does not reduce the number of cold episodes in normally nourished subjects in Western countries," says Harri Hemila of the University of Helsinki in Finland. Hemila has tracked the more than 60 studies that tested the effect of vitamin C on infections.

In the six best studies that looked at whether vitamin C can prevent colds, a total of 3,500 participants took at least one gram (1,000 mg) of C or a placebo each day for two to nine months. When the researchers pooled the studies' results, those who took the vitamin C were just as likely to catch a cold as those who took the placebo. (1)

What about taking vitamin C to shorten a cold? The last time we looked (Nov. 1994, p. 10) we concluded that "while C won't prevent colds, in some studies it helped people weather them better." But the benefit in those studies was usually modest.

"Overall, the evidence isn't very impressive," says vitamin C expert Mark Levine of the National Institute on Diabetes, Digestive and Kidney Diseases in Bethesda, Maryland.

In the four best studies, a total of 2,795 men, women, and children took from one to four grams (1,000 to 4,000 mg) of vitamin C or a placebo each day for two to three months. During that time they caught a total of 5,039 colds. (2-5)

Vitamin C didn't shorten the length of colds in any of the four studies. And in only one of the four did it ease cold-sufferers' discomfort.

When Marine recruits with colds scored their symptoms like coughing, runny noses, and sore throats on a scale of 1 (mild) to 4 (bad), those who took vitamin C rated themselves an average of 1.87, compared with an average of 1.97 by those who took a placebo. While statistically significant, that's not a big difference. (5)

However, in two of the four studies, vitamin-C-takers stayed home or were absent from school 15 to 30 percent fewer days than placebo-takers. One possibility: maybe vitamin C makes people feel better faster, but symptom scores are not sensitive enough to pick that up.

"Vitamin C is clearly important for good immunity," says Levine. "It's found in lots of immune cells, sometimes in very high concentrations. But what its function is, we don't know yet."

The Bottom Line: Taking vitamin C won't help you ward off a cold, but it may help some people weather cold symptoms slightly better.

(1) British Journal of Nutrition 77: 59, 1997.

(2) Canadian Medical Association Journal 107: 503, 1972.

(3) British Journal of Preventive & Social Medicine 30: 193, 1976.

(4) Scandinavian Journal of Infectious Diseases 9: 91, 1977.

(5) Journal of the American Medical Association 241: 908, 1979.

MULTIVITAMIN-AND-MINERAL SUPPLEMENTS

Can a simple multivitamin pill keep you well while others are sneezing and hacking their way through the cold season? Ranjit Chandra of the Memorial University of Newfoundland thinks so.

Chandra, who is a member of Nutrition Action Healthletter's Scientific Advisory Board, has formulated a special multi that's based on his decades of research into using vitamins and minerals to strengthen the immune system. He and others have tested it in three studies in Canada involving more than 900 men and women aged 50 and older.

The pill seemed to dramatically improve the volunteers' ability to fight off colds and other respiratory infections.

* Forty-eight healthy men and women aged 65 and older who took Chandra's multi every day for a year had half as many sick days as 48 others who took a placebo.

* The 22 men and women aged 50 to 65 who took Chandra's multi for a year had colds or the flu for an average of 11 days. The 22 who took a placebo were sick for 24 days. (2)

* Among 763 frail men and women (average age: 85), those who took Chandra's multi for 19 months averaged 14 percent fewer infections than those who took a placebo.

"These studies show that from middle-age on, people should take a multivitamin like this one to keep their immune systems strong and healthy," says Chandra. "This seems to be important, no matter how old you get or whether you think you're eating a good diet."

While Chandra's multi isn't sold in the U.S., it's possible that other good-quality multis may work as well (Chandra hasn't yet tested his formulation against other multivitamin-and-mineral supplements). In a 1994 study in New Jersey, 29 people aged 59 and older who were given the multivitamin Theragran-M for a year had stronger immune systems than 27 people who were given a placebo. (3) Did they get fewer--or milder--colds than the placebo-takers? The researchers didn't look.

Here's how the nutrients in Chandra's multi compare to the government recommendations (that's the Daily Value, or DV):

Vitamin or Mineral    Chandra's Multi   Daily Value

Vitamin A             1,333 IU          5,000 IU
Beta-carotene         26,600 IU         5,000 IU *
Vitamin B-1           2.2 mg            1.5 mg
Vitamin B-2           1.5 mg            1.7 mg
Niacin                16 mg             20 mg
Vitamin B-6           3 mg              2 mg
Folate (folic acid)   400 mcg           400 mcg
Vitamin B-12          4 mcg             6 mcg
Vitamin C             80 mg             60 mg
Vitamin D             140 IU            400 IU
Vitamin E             44 IU             30 IU
Iron                  16 mg             18 mg
Zinc                  14 mg             15 mg
Copper                1.4 mg            2 mg
Selenium              20 mcg            70 mcg
Iodine                200 mcg           150 mcg
Calcium               200 mg            1,000 mg
Magnesium             100 mg            400 mg

* There is no DV for beta-carotene. The DV for vitamin A (5,000 IU) can
come either from beta-carotene (which the body converts to vitamin A)
or from vitamin A (retinol).

The Bottom Line: If you're 50 or older, taking a multivitamin every day may strengthen your immune system and make you better able to ward off colds. An ordinary Centrum-like multi has essentially the same (or higher) levels of most of the nutrients in Chandra's supplement, though much less beta-carotene.

(1) Lancet 340: 1124, 1992.

(2) Nutrition Research 22: 5, 2002.

(3) American Journal of Clinical Nutrition 60: 437, 1994.

VITAMIN E

"Older people would benefit from consuming 200 International Units per day of vitamin E to boost their immune response," says immune-system expert Simin Nikbin Meydani of the Jean Mayer U.S. Department of Agriculture Human Nutrition Research Center on Aging at Tufts University in Boston. She's talking about shoring up the body's defenses not just against colds, but other infections as well.

"We have found that extra vitamin E improves T-cell-mediated immunity in both people and laboratory animals as they get older," says Meydani. That's what marshals an army of lymphocytes and other defenders that attack and destroy foreign invaders like viruses and bacteria.

In 1997, Meydani and her colleagues gave 88 healthy men and women aged 65 years or older 60 IU, 200 IU, or 800 IU of vitamin E or a placebo each day for eight months. (1)

"Two hundred International Units seemed to be the optimal dose," says Meydani. It boosted their ability to produce antibodies to hepatitis and tetanus vaccines. And it increased their bodies' response to a foreign substance. More than 200 IU a day produced no additional benefit.

"These kinds of effects of vitamin E supplements should help older people fight off colds and other infections more easily," she says. But the only way to know for sure is to see whether older people get sick less often when they take vitamin E.

That's why Meydani and her colleagues are giving 640 elderly nursing-home residents either 200 IU a day of vitamin E or a placebo and are keeping track of their illnesses. Results are expected later this year.

"We have shown that when old mice are exposed to influenza virus, giving them supplemental vitamin E reduces the amount of virus in their blood," says Meydani. "We hope to see whether vitamin E can reduce the levels of cold virus in people."

The Bottom Line: Taking 200 IU a day of vitamin E, either in a multivitamin or separately, may strengthen your immune system, which might help protect you against colds and other infections. But check with your physician if you're taking prescription drugs like warfarin or other blood thinners. Vitamin E can interact with them.

(1) Journal of the Association 277: 1380, 1997.

WHAT MAY HELP YOUR COLD

* Over-the-counter antihistamines. They'll help stop your nose from running and cut down on the sneezing. That will not only make you feel better; it'll also help keep you from spreading your germs. Some popular antihistamines: Chlor-Trimeton or Triaminic (active ingredient: chlorpheniramine), Dimetapp (brompheniramine), Tavist (clemastine), and Benadryl (diphenhydramine).

* Decongestants. A single dose of any decongestant may make you less stuffed up, but additional doses don't seem to do anything. (1) Some popular brands of decongestant pills or syrups: Sudafed, Robitussin, and Contac (all contain the active ingredient pseudoephedrine). If you use a decongestant nasal spray (like Afrin, Neo-Synephrine, or Dristan) for more than three days, watch out for rebound congestion, which makes you even more congested.

* Ibuprofen (Advil), naproxen (Aleve), acetaminophen (Tylenol), and aspirin. They can reduce your fever and ease your muscle aches. (Don't give aspirin to children with fever; it can increase their risk of potentially fatal Reye's syndrome.)

* Chicken soup. As it turns out, any hot liquid may help. Fifteen healthy volunteers produced "runnier" nasal mucus when they drank hot chicken soup or hot water than when they drank coldwater. (2) That could help move viruses and germs out of the nose more quickly.

* Liquids. When you have a cold, anything that loosens mucus and gets it moving out of your body helps. That's one of the reasons why you should drink plenty of liquids. Another good reason: if you have a fever, you could become dehydrated.

* Zicam. In a company-sponsored study, volunteers taking this over-the-counter zinc gluconate nasal gel got over their colds in an average of two days (vs. nine days for people given a placebo). (3) But in an independent study, Zicam had no effect. (4) Without more research, it's impossible to know which results are valid.

* Remdex. In three studies, volunteers who took an herbal supplement that contained Andrographis paniculata, the active ingredient in the cold remedy Remdex, had less-severe colds. But why risk taking an herb that seems to prevent rats and mice from reproducing (at least when they're given large doses for long periods of time)?

WHAT WON'T HELP YOUR COLD:

* Antibiotics. They fight bacteria, not the viruses that cause colds. (Antibiotics can help if your cold leads to a bacterial infection, though.)

* Prescription antihistamines. Drugs like Claritin and Allegra don't fight cold symptoms. In one study, however, Claritin combined with pseudoephedrine (Claritin-D) did.

(1) Cochrane Database System Review 2: CD001953, 2000.

(2) Chest 74: 408, 1978.

(3) Ear, Nose & Throat Journal 79: 778, 2000.

(4) Clinical Infectious Diseases 33: 1865, 2001.

WASHING COLDS AWAY

Germs that can make you sick are everywhere. According to an unpublished University of Arizona study, playground equipment, handrails and armrests, surfaces in public bathrooms, and shopping-cart handles are among the surfaces that are likely to have traces of saliva or other bodily fluids that could contain germs. The places where you've got to be especially careful: day care centers, gyms, doctors' offices, and restaurants.

And cold bugs can survive on your skin for several hours. So if you rub your eyes or scratch your nose--the main routes of entry--after touching a contaminated surface, the germs can hitch a ride right into your body.

The solution? "Wash, wash, wash," says cold expert Marilyn Lee of Ryerson University in Toronto. The more often people wash their hands, the less likely they are to get sick. (Experts recommend a vigorous ten-second sudsing, a rinse with plenty of warm water, and a thorough drying.)

Timing matters, too. "You should be especially careful to wash after you leave a public place or bathroom," says Lee. (Washing right after you handle raw meat, fish, or eggs won't help prevent a cold, but it can protect you from a nasty bout of E. coli or other food poisoning.)

Other things you can do to cut your downtime from colds:

* Stop smoking. If you're a heavy smoker, you're twice as likely as a non-smoker to get a cold that lasts a week or more. (1)

* Exercise. Sedentary women who started taking a brisk 45-minute walk five days a week slashed in half the number of days they were sick with colds. (2)

* Get enough sleep. Our bodies may produce fewer germ-fighting natural killer cells when we're sleep-deprived. "If you don't get at least eight hours of sleep a night, your chances of getting sick increase," says cold expert Harvey Moldofsky, medical director of the sleep disorders clinic at the Centre for Sleep and Chronobiology in Toronto.

And if you have a cold, don't spread it. Ideally, you should wash your hands every time you sneeze or blow your nose.

(1) Annals of Epidemiology 11: 225, 2001.

(2) International Journal of Sports Medicine 11: 467, 1990.