This plant from Asia has been used as a medicine for thousands of years. In ancient China, garlic was one of the most popular remedies as far back as 2700 B.C.E., and physicians used it as a treatment for depression. In India, it was prescribed for treating coughs, skin disease, rheumatism and even hemorrhoids.
Medieval Europeans mixed garlic with honey in teas and tinctures, and used it to fight infectious diseases that caused fevers and bacteria. Marseille residents were given garlic as a treatment during an outbreak of bubonic plague in the 1700s [source: Petrovska and Cekovska].
In the early 1900s, doctors gave people garlic during influenza outbreaks as a protective medicine. The belief in garlic's powers was so strong that during the flu epidemics of 1917 and 1918 in the U.S., some people wore necklaces of garlic around their necks when they went out in public. During World War II, the Soviet Army actually used it instead of penicillin. No wonder garlic was called "Russian penicillin" [source: Petrovska and Cekovska].
While garlic isn't quite the miracle cure that people wanted it to be, it does contain allicin, a substance that can kill a wide range of bacteria, including multidrug-resistant strains of E. coli [source: Ankri and Mirelman].