Health Studies Sniff Out Secrets of Garlic

Garlic, once believed to fend off demons, may also help to ward off modern killer diseases.

“We’re trying to develop new foods that will help prevent cells from becoming cancerous,” said Herbert Pierson, who is heading the National Cancer Institute’s year-old “designer foods” program.

The research is centered on garlic, linseed, licorice root, citrus fruits and members of the parsley family.

Garlic, a member of the lily family (along with onions and chives), is “a good candidate to be first,” Pierson said. “Garlic is the one we’re going after. It is consumed all over the world and already has a large database of results in animals. None of the other foods comes close.”

In trying to develop cancer-preventive foods, scientists are looking at synergistic effects and combining certain compounds for greater efficacy. Food technologists, for example, “would formulate a food and load it with the right garlic combination,” Pierson explained.

“Chopping, steaming, food-processing does miraculous things to garlic,” he added.

“Undisturbed, the garlic bulb has limited medicinally active compounds,” said Eric Block of the State University of New York at Albany, who is an authority on garlic chemistry. “Cutting triggers the formation of a cascade of compounds that are quite reactive and participate in a complex sequence of chemical reactions. Ultimately, an amazing collection of chemical compounds is produced.”

Garlic unleashes at least 100 sulfur-containing compounds that are associated with its medicinal uses. Block is analyzing the anti-coagulant properties of a compound he and his colleagues call “ajoene.”

Studies in Italy and northeastern China have found that the risk of stomach cancer among people declined in proportion to their consumption of garlic, onions and scallions, William J. Blot of the cancer institute said.

Garlic may also inhibit breast cancer, said John Milner of Pennsylvania State University. When substantial amounts of aged garlic-extract powder were fed to laboratory rats that had been treated with a cancer-causing chemical, the garlic significantly delayed the onset of mammary tumors. “In some studies, we observed a 70% reduction in the number of tumors,” Milner said. “This marked reduction places a whole new emphasis on the importance of this condiment in our diet.”

Garlic in the diet also may help lower the risk of heart disease, protect cells against damage from radiation, pollution and aging and stimulate the immune system, said Robert I-San Lin, who organized the “First World Congress on the Health Significance of Garlic and Garlic Constituents,” in Washington last August.

At the conference, 50 scientists from 15 countries compared garlic research data. Significant studies are being conducted in China, Japan, India and Germany as well as the United States. The Chinese, Japanese and Koreans are among the largest consumers of garlic in the world. Americans use more than 250 million pounds of it each year, most of it grown in California.

In India, scientists observed a substantially lower than average death rate among 222 heart patients who drank daily doses of garlic juice in milk.

Lin cautioned that people should not use any form of garlic medication until it is proved safe and effective, and to consult their physicians. Excessive amounts of raw garlic can cause anemia and inflammation of the digestive tract, he said.

A clove or two of cooked garlic a day can do no harm and may be helpful, Lin said. “I eat pickled garlic as a snack. It’s crunchy and tasty, like a roasted almond or peanut. I average a clove a day.” In Germany, garlic pills are popular.

The pills and pickled garlic do not produce fresh-garlic breath. Although garlic is called the “stinking rose,” it gives off little or no odor until it is cut or crushed, and the aroma is not critical to its health benefits.

Garlic has been used medicinally for at least 4,000 years.