Nutrition Therapy

Nutrition therapy is based on the premise that diet in general or certain vitamins and minerals in particular can prevent or cure disease. Practices range from simply eating a balanced diet to maintain good health to taking megadoses of vitamins and/or minerals to ward off disease or treat mental illness.

A growing body of scientific evidence indicates that nutrition is even more important in preventive medicine than previously thought. But the majority of doctors and nutritionists still stress that for most people, a varied diet -- low in fat and sugar, high in fiber and starches, and low enough in calories to maintain ideal weight -- will suffice.

Origins

Physicians have been prescribing special diets since the time of the ancient Greeks, and they continue to do so for patients with nutrition-related diseases. The more recent practice of megavitamin therapy (consuming at least 10 times the Recommended Dietary Allowance, or RDA) originated with Dr. Linus Pauling, a Nobel laureate chemist who coined the term orthomolecular therapy (meaning therapy with the right molecules) in 1968, when he began to advocate very large doses of vitamin C to prevent or treat the common cold. During the 1970s, megavitamin therapy was promoted as an alternative treatment for mental illness. More recently, it has been advocated by food faddists and self-styled healers, as well as some conventional practitioners, as a cure for asthma, allergies, AIDS, and even cancer. Although good nutrition plays a role in treating these problems, there is no scientific proof that it can produce a cure.

Practitioners

Nutrition therapy is practiced by many of the 46,000 registered dietitians (R.D.) who are members of the American Dietetic Association. In addition, more than 500 doctors and other health professionals have passed a qualifying examination given by the American Board of Nutrition, and an equal number of members of the American Nutritionists Association have obtained advanced degrees in this specially.

Nutritionists may be licensed and/or certified depending on state requirements. There are 29 states in which practitioners must meet certain educational standards and pass an examination before they are legally entitled to call themselves certified dietitians or certified nutritionists. But anyone, regardless of training, can call himself a nutritionist or diet counselor, a situation that has unfortunately left the door open to widespread quackery.

Many chiropractors, naturopaths, herbalists, acupuncturists, and health-food salespeople also double as nutrition counselors, as do some fitness trainers, health-club workers, and diet-center personnel.

When is Nutrition Therapy Used

Nutrition therapists are consulted to treat obesity, eating disorders, and diseases caused by deficiencies of certain vitamins and minerals. Although deficiency diseases are rare in the United States, they still occur, especially among the poor. The elderly and alcoholics are also vulnerable because they often consume very limited types and amounts of food.

Nutrition therapy has become an important component of treating diabetes, heart disease, and intestinal disorders. A nutrition therapist may also be asked to recommend dietary changes for a hyperactive child or for a person with allergies, lactose intolerance, or metabolic disorders. Healthy people, such as athletes and pregnant women, also turn to nutrition therapists for dietary advice to meet their special needs.

High-dose vitamins are used in both conventional and alternative medicine, but for very different purposes. For example, very high doses of niacin (a B vitamin) are sometimes used in conventional medicine to lower blood cholesterol. High-dose vitamin E may be prescribed to treat fibrocystic breasts, and alcoholics may be given large amounts of thiamine. Alternative practitioners, on the other hand, recommend high doses of vitamins -- the benefits of which are unproven -- for a wider range of illnesses. Research indicates that beta carotene (a precursor of vitamin A) and vitamins A,C, and E (antioxidant nutrients that offset harmful effects of oxygen metabolism) may help prevent cancer and heart disease and slow the aging process, but new data suggest that eating foods high in these nutrients is more effective than taking supplements.

How Nutrition Therapy Works

Because vitamins and minerals are essential to normal metabolism and other body functions, keeping a proper balance of them in the system is important to good health. However, a vitamin or mineral consumed in amounts greater than your body readily needs takes on the properties of a drug, and as with any drug, it carries a risk of side effects. For example, excesses of vitamins A and D, which are stored in the liver and fatty tissue, can lead to toxicity. High doses of minerals, especially iron, potassium, and lithium, can also be toxic.

What to Expect

Nutrition therapy begins with a careful health assessment and a review of the patient's diet. If the person has a chronic health problem such as diabetes, the nutrition therapist should work with the primary-care physician.

In cases that involve obesity or eating disorders, psychotherapy and behavior modification play an important role in long-term success. Some nutritionists ask that clients keep a careful food diary; others inspect the client's kitchen shelves. Occasionally, nutrition therapists even show clients how to make wise choices at supermarkets and restaurants.