The discovery isn't exactly new. Back in 1984, researchers found that zinc lozenges could reduce symptoms, but others came up with different results, and nobody could understand how zinc could have such a beneficial effect.
Now researchers from the Cochrane Systematic Review have revisited the issue, and have analyzed the results of 15 trials, involving 1,360 people. They found that any form of zinc - syrup, lozenges or supplements - work against the common cold, provided they are taken within one day of the symptoms appearing.
And children who take 15mg of zinc syrup or lozenges every day for five months catch fewer colds.
The researchers also wonder if zinc could help asthmatics, whose symptoms often worsen when they catch a cold.
(Source: Cochrane Library, February 16, 2011. CD001364).