The ancient Greek physician Hippocrates, often called the father of Western medicine actually used to prescribe garlic to treat a variety of medical conditions.
Modern science has recently confirmed many of these beneficial health effects.
Garlic oil contains sulfurous compounds. One of these, allicin, is an active constituent that provides immune benefits. Each softgel capsule is equivalent to 1,000 mg fresh garlic cloves.
Garlic supplements are 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 to a placebo.
The average length of cold symptoms was also reduced by 70%, from 5 days in the placebo group to just 1.5 days in the garlic group.
Another study found that a high dose of aged garlic extract (2.56 grams per day) reduced the number of days sick with cold or flu by 61%.
However, one review concluded that the evidence is insufficient and more research is needed.
Despite the lack of strong evidence, adding garlic to your diet may be worth trying if you often get colds. Human studies have found garlic supplements to have a significant impact on reducing blood pressure in people with high blood pressure.
In one study, 600–1,500 mg of aged garlic extract was just as effective as the drug Atenolol at reducing blood pressure over a 24-week period.
