Smart consumers know that "All Natural" on a food label doesn't mean it's nutritious or healthful. Tobacco, cocaine, vodka, marijuana and opium are All Natural, but you wouldn't want to feed them to your six-year-old.

The list of ingredients on just about any processed food is likely to include either "natural flavors", "artificial flavors", or both. Many manufacturers try to use only "natural flavors" because they know critical consumers believe they are healthier. But the distinction between natural and artificial flavors is arbitrary and absurd. It's based more on how the flavor is made than on what it contains. For example, banana flavor comes from the chemical amyl acetate. If you use amyl acetate that has been distilled from bananas with a solvent, it is a Natural Flavor. If you get it by mixing vinegar with amyl alcohol, it's an Artificial Flavor. Since they are chemically identical, taste and smell the same, it's unreasonable to think that the natural flavor is healthier than the artificial one.

If you think apples don't taste the way they used to, it may be because your taste buds are now accustomed to food that tastes more like apples than apples themselves, thanks to the chemical wizards in New Jersey who create the "flavors" of chain restaurant foods and most of the foods you buy in a box or a bag.

Flavoring formulae are top secret, and manufacturers are not required to list the contents on food labels. The strawberry flavor used in a fast-food milkshake has 47 ingredients.

I'm not saying either natural or artificial flavors are bad for you; all of the ingredients are on the "Generally Recognized as Safe" (GRAS) list, and anyway, the amounts used are incredibly small. One drop of the chemical that provides the flavor of green pepper is enough to flavor five swimming pools full of water.

But if you want food that's close to nature, use your eyes: look for fruits, leaves, flowers, stems or seeds. If someone has to print the word "natural" on a box to persuade you, it's probably not.

Gabe Mirkin, M.D.

Dr. Gabe Mirkin has been a radio talk show host for 25 years and practicing physician for more than 40 years; he is board certified in Sports Medicine and three other specialties.

Dr. Mirkin's daily features on fitness have been heard on CBS Radio News stations since the 1970's. He has written 16 books including The Sportsmedicine Book, the best-selling book on the subject that has been translated into many languages. His latest book is The Healthy Heart Miracle, published by HarperCollins.

Dr. Mirkin is a graduate of Harvard University and Baylor University College of Medicine. A Boston native, Dr. Mirkin did his residency at the Massachusetts General Hospital. He has served as a Teaching Fellow at Johns Hopkins Medical School, Assistant Professor at the University of Maryland, and Associate Clinical Professor in Pediatrics at the Georgetown University School of Medicine. He has run more than forty marathons and is now a serious tandem bicycle rider with his wife, nutritionist Diana Mirkin.