To conduct a series of phase I studies involving double-blind intervention with naturally occurring constituents of garlic. Briefly the protocol will involve the following components: Subject Recruitment: Healthy men and women will be recruited by the Beltsville Human Nutrition Research Center from individuals residing in the surrounding community. Each prospective volunteer will sign an informed consent and be evaluated for eligibility on the basis of a physical examination, standard clinical chemistries, and health and diet histories. Treatment: Subjects will be assigned randomly to treatments consisting of varying amounts of garlic selected for homogeneity of organosulfur compound concentration. The exposure range will be limited to intakes that are within typical dietary exposures worldwide. All preparations will be administered daily as foods, either as the intact food item or an extract incorporated into a food matrix. Subjects will receive that assigned dietary regiment for up to 60 days. Endpoints: Blood and urine samples will be collected from subjects before and after each dietary intervention. These samples will be analyzed for biomarkers of cancer risk, such as factors reflecting DNA damage, markers of inflammation, and activity of drug metabolizing enzymes. Measurements may include (but will not be limited to) 8-OH-deoxyguanosine, lymphocyte DNA damage (COMET), F2-isoprostanes, interleukin 6, C-reactive protein, and other markers of cancer risk.
