Garlic is a staple ingredient in many cuisines around the world and in many cultures people have used it as a medicine. Garlic belongs to the Allium family of vegetables, which also includes onions, scallions, shallots, leeks and chives. Whether raw, sauteed, roasted or dried, garlic is enjoyed for its pungent and unique flavor.

What’s in Garlic?

Researchers are studying a variety of substances in garlic for their potential health benefits and anti-cancer activity. Garlic contain allyl compounds that are responsible for its odor and flavor. Because the serving size garlic is just 1 teaspoon, the amount of nutrients and compounds per serving is small.

• Allicin: a bioactive compound released when garlic is crushed or chopped. Allicin forms several oil soluble allyl sulfur compounds; research has focused on few of these compounds for potential health benefits. These benefits may include decreasing inflammation and processing antimicrobial properties.
• S – allyl cysteine: A water – soluble allyl sulfur compound found in high doses in aged garlic extract.
• Flavonoids, especially Kaempferol and Quercetin: compounds well studied for their anti-cancer properties.
• Inulin: A plant storage carbohydrate that stimulates growth of beneficial bacteria in the colon, helping to protect against pathogens, toxins and carcinogens.
• Saponins: Compounds studied for anti-tumor activity.

Does Garlic prevent Cancer?

A host of studies provide compelling evidence that garlic and its organic allyl sulfur components are effective inhibitors of the cancer process. These studies reveal that the benefits of garlic are not limited to a specific species, to a particular tissue, or to a specific carcinogen. Of 37 observational studies in humans using garlic and related allyl sulfur components, 28 studies showed some cancer preventive effect. The evidence is particularly strong for a link between garlic and prevention of prostate and stomach cancers. However, all of the available information comes from observational studies comparing cancer incidence in populations who consume or do not consume garlic (epidemiologic studies), animal models, or observations with cells in culture. These findings have not yet been verified by clinical trials in humans.

Can “too much” Garlic be harmful?

Although health benefits of garlic are frequently reported, excessive intake can have harmful effects. Studies have reported symptoms including garlic odor on breath and skin, occasional allergic reactions, stomach disorders and diarrhea, decrease in serum protein and calcium levels, association with bronchial asthma and contact dermatitis, and possible associations with production of sperm in males. Garlic preparations vary in concentration and in the number of active compounds they contain. Thus, quality control is an important consideration when foods such as garlic are considered for use as a cancer-fighting agent.

How might Garlic prevent Cancer?

Several compounds are involved in garlic’s possible anticancer effects. Garlic contains allyl sulfur and other compounds that slow or prevent the growth of tumor cells. Allyl sulfur compounds, which occur naturally in garlic and onions, make cells vulnerable to the stress created by products of cell division. Because cancer cells divide very quickly, they generate more stressors than most normal cells. Thus, cancer cells are damaged by the presence of allyl sulfur compounds to a much greater extent than normal cells.

The chemistry of garlic is complicated. As a result, the quality of garlic products depends on the manufacturing process. Peeling garlic and processing garlic into oil or powder can increase the number and variety of active compounds. Peeling garlic releases an enzyme called allinase and starts a series of chemical reactions that produce diallyl disulfide (DADS). DADS is also formed when raw garlic is cut or crushed. However, if garlic is cooked immediately after peeling, the allinase is inactivated and the cancer-fighting benefit of DADS is lost. Some scientists recommend waiting 15 minutes between peeling and cooking garlic to allow the allinase reaction to occur.

Processing garlic into powder or garlic oil releases other cancer-fighting agents. The inconsistent results of garlic research may be due, at least in part, to problems standardizing all of the active compounds within garlic preparations. Some of the garlic compounds currently under investigation are: allin (responsible for the typical garlic odor), alline (odorless compound), ajoene (naturally occurring disulfide), diallyl sulfide (DAS), diallyl disulfide (DADS), diallyl trisulfide (DAT), S-allylcysteine (SAC), organosulfur compounds, and allyl sulfur compounds.@cancerqueries