Too much is made of the 4,000 chemicals in tobacco smoke. We're told these chemicals are so harmful that they are responsible for the deaths of millions worldwide. Untold in this "war on tobacco" is that each of the plants we consume consists of an equally daunting thousands of chemicals many of which are recognized poisons or suspected cancer-causing agents. Cayenne peppers, carrots and strawberries each contain six suspected carcinogens; onions, grapefruit and tomato each contain five -- some the same as the seven suspected carcinogens found in tobacco. High-heat cooking creates yet more dietary carcinogens from otherwise harmless...