This natural substance found in tomatoes provides powerful antioxidant activity that is regarded as twice as potent as beta-carotene and 100 times as effective as Vitamin E. Research indicates that this substance protects tissues and genes from toxic free radicals and chemical carcinogens, and has been shown to be a potent anti-cancer agent, inhibiting the growth of breast, lung, ovarian and prostate cancer cells. This substance also prevents oxidation of LDL cholesterol, which can lead to atherosclerosis. What is this natural substance?