Garlic for the common cold

Garlic is popularly believed to be useful for the common cold. This belief is based on traditional use, and some laboratory evidence that garlic has antibacterial and antiviral properties. On average, adults have two to four common colds per year. The evidence is current to the 7 August 2014. Of the eight studies identified, only one fulfilled the criteria for the review. This study assessed 146 participants over a three-month period. Half the participants took a placebo tablet and half took a garlic tablet during this time. The participants then wrote in a diary when they had symptoms of a cold. The included study found that people who took garlic every day for three months (instead of a placebo) had fewer colds. That is, over the three-month period, there were 24 occurrences of the common cold in the garlic group, compared to 65 in the placebo group. When participants experienced a cold, the length of illness was similar in both groups (4.63 versus 5.63 days).