Biologically based practices use naturally occurring substances and include biologic therapies (eg, shark cartilage to treat cancer, glucosamine to treat osteoarthritis), diet therapies, herbalism (see Dietary Supplements), orthomolecular medicine, and chelation therapy.

Diet Therapy

Diet therapy uses specialized dietary regimens (eg, Gerson therapy, macrobiotic diets, Pritikin diet) to treat or prevent a specific disorder (eg, cancer, cardiovascular disorders) or generally promote wellness. Some diets (eg, Mediterranean diet) are widely accepted and encouraged in traditional western medicine. The Ornish diet, a very low-fat vegetarian diet, can help reverse arterial blockages that cause coronary artery disease and may help prevent or slow the progression of prostate and other cancers. Some people following a macrobiotic diet have reported cancer remission, but a well-controlled clinical study has not been conducted. Because it usually takes months or years for benefits to be realized, diet therapy is more likely to be effective if started early.

Orthomolecular Medicine

Orthomolecular medicine, also called nutritional medicine, aims to provide the body with optimal amounts of substances that naturally occur in the body. Nutrition is the focus in diagnosis and treatment.

This therapy differs from diet therapy because it uses supradietary doses of individual micronutrients. High doses of vitamins, minerals, enzymes, hormones (eg, melatonin), amino acids, or various combinations may be used. Practitioners believe that people's nutritional needs far exceed the recommended daily allowances and that nutritional therapy must be individualized based on each patient's medical profile. High doses of micronutrients are also used as biologic response modifiers in an attempt to modulate inflammation and other disease processes. Doses may be administered orally or, far less often, intravenously.

Evidence and uses: Treatment claims include benefit for a wide range of disorders (eg, cancer, cardiovascular disease, chronic fatigue, chronic pain, autism, psychiatric disorders). These treatments are widely used, and many patients report clinical improvement. However, no clinical study data support the usefulness of most of these practices. Exceptions include use of high-dose fish oils to treat hypertriglyceridemia (and possibly inflammatory and mood disorders), use of high-dose antioxidants to prevent macular degeneration, and possibly high-dose melatonin to prevent or treat cancer. If sufficient evidence of usefulness is shown, treatments (eg, high-dose fish oils to treat hypertriglyceridemia, high-dose antioxidants to prevent macular degeneration) become part of conventional medicine.

Possible adverse effects: Clinicians should be aware that high-dose micronutrients may cause harm; eg, some micronutrients may increase the risk of developing prostate cancer or blunt the effects of certain cancer treatments.

Chelation Therapy

In chelation therapy, a drug is used to bind with and remove hypothesized excess or toxic amounts of a metal or mineral (eg, lead, copper, iron, calcium) from the bloodstream. In conventional medicine, chelation therapy is a widely accepted way to treat lead and other heavy metal poisoning (see Poisoning: Treatment). Chelation therapy with EDTA (ethylene diamine tetraacetic acid) has also been suggested as a way to remove calcium and thus treat atherosclerosis; whether this use is safe and effective has not been proved but is under study.

Last full review/revision February 2010 by Steven Rosenzweig, MD

Content last modified February 2012