Zinc may help a cold, but use caution

Some people insist zinc can prevent a cold. There's no proof it can. But according to the UC Berkeley Wellness Letter, there is some evidence that oral zinc may decrease the duration of a cold.

Suck on zinc lozenges - especially within 24-hours of getting the first symptoms - and that cold may go away a day sooner and the symptoms may be somewhat less severe.

Here's the one caution about zinc:

"Never, ever spray it in your nose," says Dr. John Swartzberg, who heads the editorial board at the Wellness Letter.

"What it can do if you spray it up your nose, it can damage the olfactory nerves, the nerves that allow us to smell. And not only does it damage them, but it permanently damages them. And it's left a considerable number of people who will spend the rest of their lives never being able to smell anything."

Even zinc lozenges can have unpleasant side effects such as nausea, diarrhea and cramps. That's why the Wellness Letter advises taking them with caution and only for the first day of symptoms.

High doses of zinc over the long-term can actually weaken your immunity.

For more information

Cold Supplements, from Airborne to Zinc