Doctor K: Cure for cold remains elusive

DEAR DOCTOR K: Is there any way to prevent a cold?

DEAR READER: The typical cold is a relatively mild misery that goes away without special treatment after about a week. Still, it’s a misery most of us would rather avoid.

Colds are caused by viruses – more than 200 different types. Because the infection is not bacterial, antibiotics don’t help. Over-the-counter cold medicines are available, but not always effective.

So the search continues for anything that can fend off cold-causing viruses or speed their exit from your body. Here is a rundown of some of the candidates.

• Vitamins. Nobel laureate Linus Pauling proposed that large daily doses – 1,000 to 2,000 milligrams – of vitamin C could prevent colds. Pauling was a genius who made major scientific discoveries and was awarded the Nobel Prize. But even geniuses can be wrong. By and large, research hasn’t supported his assertion.

• Echinacea. The research hasn’t been very encouraging. One review found some evidence that a certain part of one particular species of the Echinacea plant family might be an effective early treatment for colds in adults. Not exactly a ringing endorsement.

• Zinc. The results have been mixed. A 2011 meta-analysis found that generally healthy people who took zinc within 24 hours of the onset of cold symptoms reduced the duration and severity of their colds, compared to people who took a sugar pill. But there’s no word yet on what dose and formulation of zinc is best.

• Exercise. Here’s another reason to work out. Regular exercise may put your body in a better position to fight off a cold. Regular exercise seems to invigorate the immune system.

• Sleep. Your mother was right: Getting a good night’s sleep keeps you healthy and may keep colds away. In one study, people who got less than seven hours of sleep a night were almost three times as likely to get a cold as those who got eight or more hours of sleep.