Lee Swanson Research Update

Garlic May Protect Against Colon Cancer

November 2007

A research team from the University of South Australia examined studies from the last decade and found consistent scientific evidence that garlic may protect against development of colorectal cancer (CRC).

"Colorectal cancer is the third leading cause of cancer death in the United States and the second leading cause of cancer death in Australia," researchers noted. "Environmental factors play important roles in the multiple-stage process of CRC and nutritional intervention has been identified as playing a major role in its prevention. The aim of this study was to review systematically the scientific evidence from all studies conducted over the last decade that examined effects of garlic on CRC."

In their study, published in the Journal of Nutrition, researchers ranked studies from the last decade from level I to level V, according to study designs and assessed the quality of each study based on a set of criteria used by the national Health and Medical Research Council in Australia.

One randomized controlled trial reported a 29% reduction in size and number of colon adenomas (a collection of growths) in CRC patients taking a garlic extract. Five of eight case control/cohort studies (level III) suggested a protective effect of high intake of raw or cooked garlic; two of the studies suggested a protective effect for the distal colon.

A meta-analysis (level III) of seven of the studies confirmed the beneficial association of garlic. Eleven animal studies (level V) demonstrated a significant anticarcinogenic effect of garlic or its active constituents.

Journal of Nutrition 137(10):2264-2269, 2007

New to Natural Health?
Tools
Customer Service