Foods that can aid in the treatment and prevention of chronic diseases include non-starchy carbohydrates (such as dietary fiber, resistant starch, and fucoidan), antioxidants (including organosulfur compounds, polyphenols, carotenoids, tocopherols, tocotrienols, phytosterols, and isoflavones), unsaturated fatty acids, bioactive peptides, sterols, and phytoestrogens. In conventional medicine, garlic is used to prevent and treat cancers of the blood, breast, prostate, ovary, and gastrointestinal system. Active phytoconstituents of garlic include diallyl thiosulfinate, methyl allyl trisulfide, diallyl tetrasulfide, S-allyl cysteine sulfoxide, dipropyl sulfide, diallyl trisulfide, 3-vinyl-4H-1,2-dithiin, allyl methane sulfinate, diallyl disulfide, dipropyl disulfide, allyl methyl thiosulfinate, S-methyl cysteine sulfoxide, 3-vinyl-6H-1,2-dithiin, dimethyl disulfide, dimethyl sulfide, methylpropyl disulfide, S-propyl cysteine sulfoxide, 3-vinyl-6H-1,3-dithiin, and methyl methane sulfinate. Garlic derivatives, including diallyl disulfide, are found to be highly effective in suppressing the growth of breast cancer cells. Mechanisms behind this growth suppression include activating metabolizing enzymes for carcinogen detoxification, inhibiting the generation of reactive oxygen species (ROS) and DNA adduct formation, controlling the cell cycle, inducing apoptosis, and repairing DNA damage.