Group and Discussion Activities

Key Questions

  1. Does food consist of chemicals? [Yes.}
  2. How can a knowledge of chemistry help you decide what food to eat or buy? [You can read and interpret the labels and not be fooled by false or ambiguous advertising.]
  3. An advertisement states that a prune, ounce for ounce, has more vitamins than a plum. Why is this statement misleading? [Only water is removed from the plum to make a prune. The vitamins remain, but the mass is less. You get the same mass of vatamins from a prune as from a plum.]
  4. Are food additives bad?[Not always; they can protect from spoilage and deficiency-diseases.]

Counterintuitive Examples

  1. Labels do not tell the whole story. There are many prepared foods that contain compounds that cannot be digested; drugs or cosmetics may contain compounds to which one is allergic; drugs or foods may contain nutrients in a form the body does not use.
  2. Enriched flour vs. whole wheat flour. White flour is prepared by removing some of the bran and germ. White flour is bleached with benzol peroxide. Enriched flour has had nutrients added to it. The whole wheat flour is made from the whole grain. It may also have added nutrients. It does not last as long as white flour because the oil from the wheat germ becomes rancid, so preservatives are often added.
  3. Refined white sugar vs. honey. White sugar is recrystallized sucrose, a chemical combination of glucose and fructose, extracted from sugar cane or sugar beets, usually by concentrating the syrup and letting the crystals form. The brown decomposition products of this process are removed in the refining. Brown sugar is white sugar to which molasses has been added. When sucrose is eaten, an enzyme in the body changes it to glucose and fructose. Honey is a solution of sugars produced by bees, a 50/50 mixture of glucose and fructose. In terms of sugar content, refined white sugar and honey are equivalent. Judgments regarding the choice of honey over refined sugar become matters of personal preference.
  4. All food additives are harmful. Preservatives, such as sugar and salt, and antioxidants, such as lemon juice, have been used for thousands of years as additives. Additives can be very important in an urban society where food may be shipped long distances before being used. The safety of the additives is monitored by the FDA. However, some people may have a reaction to a specific additive, such as MSG (monosodium glutamate) and should read labels or inform food providers of the problem.
  5. It is safe to eat fat or food containing cholesterol. Some fat and cholesterol are necessary for healthy body functions. The body even manufactures cholesterol for its use and uses if for the vital biological role of the formation of steroid hormones (sex hormones) and Vitamin D. If the body does not provide enough cholesterol, some must be eaten. Fats are a source of long term energy storage.