Science / Medicine : NEWS FROM THE Cold Front : Button up your overcoat. And take your Vitamin C. Mom’s remedies may have made us feel better, but the newest medical research says some common treatments may not help, and some could even be harmful.
With the arrival of the cold and flu season, many people are stacking their medicine chests with Vitamin C, zinc, antihistamines and aspirin, but whether these compounds will ward off colds or flu or help fight these infections is highly doubtful, recent research indicates.
Although initial studies suggested that large quantities of Vitamin C or zinc tablets dissolved slowly in the mouth could prevent colds, larger and better-controlled studies show these compounds have no effect on the number of colds to which people succumb. One study done at the University of Virginia indicated that zinc actually worsened cold symptoms.
Vitamin C may slightly reduce the severity or duration of cold symptoms, but conclusive evidence is lacking. Taking large doses of Vitamin C over long periods of time, however, may be harmful. It can prompt severe diarrhea, for example, which poses a particular danger for elderly people and small children.
Other cold mainstays to recently come under question are antihistamines. Histamines are infamous for their ability to spur the runny noses and congestion that plague many allergy sufferers. Most people assumed that histamines also prompted these same symptoms when the nose is attacked by a cold virus. But recent studies by University of Virginia and Johns Hopkins University researchers showed that the levels of histamines do not rise in patients infected with cold viruses, and antihistamines do not help reduce cold symptoms. Although histamines and cold viruses trigger some of the same symptoms, they may do so by different biochemical pathways.
A panel of clinicians and scientists suggested in the March, 1988, issue of the Journal of Pediatric Infectious Diseases that cold sufferers lay off the antihistamines unless they are also experiencing allergy symptoms. The panel also pointed out that antihistamines do not prevent ear infections when given to children with colds, despite their common use for this purpose.
Another popular misconception is that colds stem from not dressing warmly enough in cold weather. Probably everyone has been told by their mother at some point that they are going to “catch a death of a cold” if they don’t put on a sweater. But according to the National Institute of Allergies and Infectious Diseases, studies show that exposure to cold weather or getting chilled or even overheated has little or no effect on the development or severity of a cold. The infections apparently are more common during winter months because people spend more time indoors, so cold viruses can hop from person to person with ease.
Nobody likes to have a runny nose, congestion or a cough, but all these symptoms help rid the body of a cold or flu virus. The excess mucous generated during a cold is filled with infection-fighting compounds like interferon and antibodies that thwart invading viruses, research reveals. A stuffy nose stems from a stepped up blood flow carrying an armory of infection-fighting cells and compounds to infected nasal passages.
Unfortunately, the inflated blood supply swells shut or narrows nasal passages, causing a buildup of mucus. Coughing rids the body of infected mucus.
Because all these factors help bring a cold to a close, some physicians believe that countering cold symptoms with decongestants, cough suppressants and mucus thinners called expectorants is counterproductive.
“These drugs defeat the body’s own defenses,” said Connecticut pediatrician and American Academy of Pediatrics spokesman Dr. Henry Harris. “The body is much smarter than we are.”
But colds researcher Dr. Jack Gwaltney of the University of Virginia disagrees, citing results of studies he has done, which show effective decongestants make cold symptoms milder and not as long-lasting.
His research also reveals that one-third of all volunteers infected with a cold virus to which they are susceptible do not develop any cold symptoms. Apparently the body has ways of ridding itself of a cold virus, Gwaltney said, without prompting uncomfortable symptoms.
When colds and flu do strike, however, victims should be aware that continued use of decongestants can prompt a rebound effect, worsening congestion. The Food and Drug Administration recommends that decongestants be taken for no more than three days in a row.
There are also differing viewpoints concerning the use of drugs to counter fever. Most physicians recommend aspirin for adults and Tylenol and other brands of acetaminophen for children (because of aspirin’s reported link to Reyes syndrome in children) to combat the fever and aches and pains that accompany colds and flu.
But some animal research suggests that fever boosts the chances of surviving infection, apparently by killing off microbes, such as cold and flu viruses, which thrive in temperatures between 86 degrees and 95 degrees. Higher body temperature may also heighten immune defenses.
Fever prompts an increase in white blood cell activity and interferon production in humans, studies show. Fever also spurs a shortage of circulating levels of iron, which many pathogens need for growth and reproduction.
Although a high fever can signal a dangerous illness, the fever itself usually will not cause any bodily harm. A high fever does cause such discomforts as body aches, chills and fatigue, however, which a fever-lowering drug such as aspirin or acetaminophen will often relieve.
NEW WEAPONS IN THE COLD WAR
Antikinins. Studies suggest that proteins called kinins may promote a stuffy or runny nose and sore throat. Experiments show that levels of kinins are tied strongly to the first appearance and severity of cold symptoms. Researchers are testing antikinin drugs that could halt symptoms, but not viruses. The body’s antibodies and immune system would still have to fight the virus.
Interferon. This protein is generated by the immune system to prevent viruses from multiplying. Initial tests of an interferon nasal spray show that while it may prevent colds, it can cause nose irritation, bleeding and burning side effects worse than cold symptoms. More recent tests of a lower-dose interferon spray showed it nearly cut in half the number of colds in volunteers exposed to a range of viruses. The FDA is considering the spray for use in adults to prevent colds.
A Cure? A cure for the “common cold” has been slow to surface because several different types of viruses cause colds, according to Jack Gwaltney of the University of Virginia. “But if we keep chipping away at it, eventually we’ll develop effective drugs.”
