Garlic Has Minimal Cancer-Prevention Effects
Meta-analysis shows either little or no association between intake and risk of common cancers
THURSDAY, Jan. 8 (HealthDay News) -- Evidence suggests that garlic consumption has little or no effect in reducing the risk of many common cancers, according to a report published in the January issue of the American Journal of Clinical Nutrition.
Ji Yeon Kim, M.D., of the Korea Food and Drug Administration in Seoul, and a colleague used the U.S. Food and Drug Administration's evidence-based review system to conduct a meta-analysis of 19 human studies.
The researchers found very limited evidence to support an association between garlic consumption and a reduced risk of colon, prostate, esophageal, larynx, oral, ovary or renal cell cancers. But they found no credible evidence to support an association between garlic consumption and a reduced risk of gastric, breast, lung or endometrial cancer.
"Because garlic is intended to be used in small amounts for seasoning purposes, it is very difficult to analyze the quantity of garlic consumption by means of food-frequency questionnaires," the authors conclude. "Moreover, there are too many variables that can affect the chemical composition of garlic, such as the preparation method used (e.g., whether the garlic is raw or cooked, whole, or extracted) and the conditions of cultivation. For some of these reasons, although this systematic review found many studies on garlic intake and cancer, most of the results indicate that additional studies were needed."