Aged garlic extract has potential suppressive effect on colorectal adenomas in humans

Abstract

Epidemiological and animal studies suggest AGE and its organosulfur constituents, such as S-allylcysteine and S-allylmercaptocysteine have anticarcinogenic effects. To confirm these effects in humans, a preliminary double-blind, randomized clinical trial using high-dose AGE (AGE2.4 mL/d) as an active treatment and low-dose AGE (AGE 0.16 mL/d) as a control was performed on patients with colorectal adenomas-precancerous lesions of the large bowel. The study enrolled 51 patients who were diagnosed as carrying colorectal adenomas. The patients were randomly assigned to the two groups after adenomas larger than 5 mm in diameter were removed by polypectomy. The number and size of adenomas right before intake (0 mo) and at 6 and 12 mo after intake were measured using colonoscopy. Thirty-seven patients (19 in the active group, 18 in the control group) completed the study and were evaluated for the efficacy of AGE. The number of adenomas increased linearly in the control group from the beginning (the baseline), but AGE significantly suppressed both the size and number of colon adenomas in patients after 12 mo of high-dose treatment (P = 0.04). The results suggest AGE suppresses progression of colorectal adenomas in humans. It appears that AGE has multiple pathways to reduce cancer incidence and suppress its growth and proliferation. © 2006 American Society for Nutrition.