Do findings from clinical trials offer evidence that garlic may prevent cancer?
Few clinical trials (research studies with people) have been done to examine the potential anticancer effects of garlic. Three randomized clinical trials have evaluated the effect of garlic intake on gastric cancer risk. In one study, which involved over 5,000 Chinese men and women at high risk for stomach cancer, researchers compared the effects of taking a combination of 200 mg synthetic allitridum (an extract of garlic used as a medicine in China for over 3,000 years) daily and 100 micrograms selenium every other day with taking a placebo (an inactive substance or treatment that looks the same as, and is given the same way as, an active drug or treatment being tested) for 5 years. In the group that received allitridum and selenium, the risk for all tumors combined was reduced by 33 percent and the risk for stomach cancer was reduced by 52 percent in comparison with the group that received only the placebo (13). In contrast, findings from another randomized trial involving individual
