Studies show a variety of substances in garlic have anti-cancer activity.  Italian researchers found that people whose diets are rich in onions, garlic, and other alliums have a much lower risk of several types of cancer than those who avoid the pungent herbs.

Researchers at the Medical University of South Carolina have found that a compound in garlic may be effective at shrinking brain tumors, notably the most aggressive and lethal kind, glioblastoma.

Garlic contains allicin, a powerful plant compound that is antibiotic and anti-fungal. Garlic's antibacterial properties may help to prevent cancer as well as enhance genetic repair, slow down cell proliferation, and prevent the formation of carcinogenic substances in the body.

The amount of garlic in typical cooking is very small, but regularly adding fresh chopped or smashed garlic to various foods like pasta dishes, will provide many benefits.