There have been widespread claims that zinc supplements can do just that.
Now a study in the Canadian Medical Association finds some truth to the claims.
In some cases, higher doses of zinc taken orally by adults can shorten a cold by as much as two days. However, in the research, children under 18 got no such benefit.
The form of zinc also mattered. Zinc acetate was better than gluconate or zinc sulfate.
The FDA has warned against the use of nasal sprays with zinc because they have been linked to the permanent loss of smell.
