How effective is garlic for the prevention or treatment of the common cold?
Only one trial that met the selection criteria was identified, limiting the conclusions that can be drawn. Inclusion and exclusion criteria were not reported, nor were differences in comorbidity or concurrent illnesses. These factors reduce the generalisability of the trial and may have introduced bias into the results. No trial was identified that looked at whether taking garlic for symptoms of the cold reduces its severity or duration. However, in the included study, the number of days to recover from a cold was similar for both groups.
Garlic is alleged to have antimicrobial and antiviral properties that relieve the common cold, among other beneficial effects. There is widespread usage of garlic supplements. The common cold is associated with significant morbidity and economic consequences. On average, children have 6 to 8 colds per year, and adults have 2 to 4.