Garlic is closely related to onion and chives. The largest commercial garlic production is in central California. The bulb is used. Garlic is mentioned in the Bible and the Talmud. Hippocrates, Galen, Pliny the Elder, and Dioscorides all mention the use of garlic for many conditions, including parasites, respiratory problems, poor digestion, and low energy. Its use in China was first mentioned in A.D. 510. Louis Pasteur confirmed the antibacterial action of garlic in 1858.

Active constituents of garlic

The sulfur compound allicin, produced by crushing or chewing fresh garlic, in turn produces other sulfur compounds: ajoene, allyl sulfides, and vinyldithiins.

Cardiovascular actions of garlic

Many publications have shown that garlic supports the cardiovascular system. It may mildly lower cholesterol and triglyceride levels in the blood, inhibit platelet stickiness (aggregation), and increase fibrinolysis—which results in a slowing of blood coagulation. It is mildly antihypertensive and has antioxidant activity. Three reviews of double blind studies in humans have found that garlic can lower blood cholesterol levels in adults by approximately 10%. Garlic has been shown to be as effective as the drug bezafibrate in lowering cholesterol levels. However, a recent placebo-controlled study found no effect for garlic on lowering cholesterol. Several double blind studies also suggest it can prevent atherosclerosis. Garlic is also helpful for persons with intermittent claudication (cramping in the lower legs secondary to poor blood flow), according to one controlled study.

Antimicrobial actions of garlic

Garlic has antibacterial, antiviral, and antifungal activity. It may work against some intestinal parasites. Garlic appears to have roughly 1% the strength of penicillin against certain types of bacteria. This means it’s not a substitute for antibiotics but it can be considered as a support against some bacterial infections. Candida albicans growth is inhibited by garlic, and garlic has shown long-term benefit for recurrent yeast infections. However, controlled human studies have yet to show garlic helps for yeast infections.

Anticancer actions of garlic

Human population studies show that eating garlic regularly reduces the risk of esophageal, stomach, and colon cancer. This is partly due to garlic’s ability to reduce the formation of carcinogenic compounds. Animal and test tube studies also show that garlic and its sulfur compounds inhibit the growth of different types of cancer—especially breast and skin tumors.

How much garlic is usually taken?

Some people chew one whole clove of raw garlic per day. For those who prefer it, odor-controlled, enteric-coated tablets or capsules with standardized allicin potential can be taken in amounts of 600–900 mg in two or three divided doses (providing up to 5,000 mcg of allicin potential).

Information on this site is provided for informational purposes and is not meant to substitute for the advice provided by a licensed physician. You should not use the information on this website for diagnosing or treating a health problem or disease, or prescribing any medication.