Garlic supplementation is known to boost the function of the immune system.
One large 12-week study found that a daily garlic supplement reduced the number of colds by 63% compared with placebo (4).
The average length of cold symptoms was also reduced by 70%, from 5 days in placebo to just 1.5 days in the garlic group.
Another study found that a high dose of garlic extract (2.56 grams per day) can reduce the number of days sick with cold or flu by 61% (5).
If you often get colds, then adding garlic to your diet could be incredibly helpful.
Bottom Line: Garlic supplementation helps to prevent and reduce the severity of common illnesses like the flu and common cold.