Onions and Garlic May Prevent Cancers

Study Shows Eating Lots of the Pungent Herbs May Keep Certain Types of Cancer at Bay

Medically Reviewed by Louise Chang, MD on November 21, 2006
From the WebMD Archives

Nov. 21, 2006 -- Better load up on the breath mints; a new study suggests eating lots of garlic and onions may help prevent cancer.

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.

Researcher Carlotta Galeone, of the Istituto di Ricerche Farmocologiche "Mario Negri" in Milan, and colleagues say the health benefits of onion and garlic have been touted for centuries, but few studies have been able to prove the benefits.

Pungent Cancer Prevention

In their study, researchers used data from several Italian and Swiss cancer studies to look at the relationship between onion and garlic consumption and cancer at several body sites, including the mouth, larynx, esophagus, colon, breast, ovary, and kidneys.

Overall, consumption of onions ranged from 0-14 portions per week among cancer patients and 0-22 portions per week among those without cancer.

Garlic use was also lower among people with cancer, except for those with cancer of the breast, ovary, or prostate.

Researchers found moderate consumption of onions appeared to reduce the risk of colorectal, laryngeal, and ovarian cancers.

The protective effect was even greater among those who ate the most onions compared to those who ate the least. People who ate the most onions also had a lower risk of oral and esophageal cancers than those who ate the least.

Moderate use of garlic was also associated with a lower risk of colorectal and renal cell (a type of kidney cancer) cancers.

Again, the anticancer effect increased with the more garlic they ate. People who ate the most garlic had a lower risk of all cancers except breast and prostate cancers, which are mainly associated with hormonal and reproductive issues, write the researchers.

Researchers say onion and garlic consumption could simply be a marker for a healthier lifestyle and a diet high in a variety of potentially cancer-fighting herbs and vegetables.

However, the protective effect of onions and garlic against cancer remained significant even when they controlled for total vegetable intake.

Their results appear the American Journal of Clinical Nutrition.

Show Sources

SOURCE: Galeone, C. American Journal of Clinical Nutrition, November 2006; vol 84: pp 1027-1032.

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