Complementary and Alternative Medicine (CAM) Supplement Use in People with Diabetes: A Clinician's Guide. Laura Shane-McWhorter

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СКАЧАТЬ remedies and conventional medications.⁴² Some of the commonly used products included aloe vera (sábila) and prickly pear cactus (nopal).⁴² Another important finding in this study of Hispanics, with important implications for clinicians, was that many of the participants believed that diabetes may be caused by fright (susto) or anger (coraje) and that insulin may cause blindness and become an addiction. Other surveys of Hispanic patients have found that folk remedies such as herbal teas or other botanical products were used by 33%⁴³ to 64%.¹⁵ Unlike studies that have stated that <40% of patients reported use of CAM supplements to their provider,⁶ studies in Hispanics have found that as many as 69% did not report use of herbal remedies.¹⁵ Hence, clinicians should be more proactive in asking their Hispanic patients about CAM supplement use.

      CAM supplement use has also been reported across several age groups. One study reported that dietary supplements were used by children with chronic diseases including asthma, cancer, cystic fibrosis, diabetes, hepatic or renal disorders, and rheumatology and neurobehavioral disorders.⁴⁴ In the children with diabetes, 31% were using a nonprescribed supplement.⁴⁴ On the opposite end of the age spectrum, a small multiethnic sample of older individuals found that 15% used herbal remedies and 5% used teas to treat their diabetes.⁴⁵ In female seniors who were members of a health plan, 11% of women with diabetes used herbal products.⁴⁶

REGULATION OF CAM SUPPLEMENTS

      Dietary supplements do not need FDA approval before being marketed.⁴ Prior to 1994, CAM supplements were classified as foods or drugs, depending on the intended use. In 1994, Congress passed the Dietary Supplement Health and Education Act (DSHEA), which created a separate category for botanicals and other products.⁴⁷ Now they are classified as dietary supplements.⁴⁷ This legislation allows dietary supplements to forego the same stringent approval process that is required for drugs, and therefore proof of safety and efficacy is not required for marketing.

      The reclassification has resulted in a serious consequence. Sometimes contaminants or substitutes have been found in the products. For instance, as noted above, some diabetes products have been contaminated with lead,^29,30 and other products touted as being “herbal” have been found to contain prescription drugs such as chlorpropamide or glyburide.^28,48

      A possible solution would be the use of standardized products. Standardization guarantees that each dose provides a consistent level of the active ingredient. However, proponents of biological complementary therapies argue that standardized extracts may not always contain all of the therapeutic ingredients found in the natural product. A pertinent factor is whether the standardized preparation actually reflects the labeled information.²²

      DSHEA allows manufacturers of dietary supplements to make claims regarding the ability to maintain “structure and function” of the body, but does not allow claims regarding diagnosis, treatment, cure, or prevention of disease.⁴⁷ If a manufacturer claims the product affects body structure or function, the label must include the following statement: “This statement has not been evaluated by the Food and Drug Administration (FDA). This product is not intended to diagnose, treat, cure, or prevent any disease.” The manufacturer must also notify the FDA within 30 days after a product is on the market if it bears such a label.

      FDA has implemented regulations that ban implied as well as expressed disease claims.⁴⁷ For example, claims made by a manufacturer that a patient could misconstrue as indicating treatment or prevention of a disease are no longer allowed. In the new regulations, a product may make health maintenance claims but not disease claims (“maintains a healthy prostate” is allowed, but “treats benign prostatic hyperplasia” is not).

      FDA has published a Dietary Supplement Strategy (Ten Year Plan).⁴⁹ The year 2010 is the target year when FDA will have a “science-based regulatory program that fully implements DSHEA, in an effort to provide consumers with a high level of confidence in the safety, composition, and labeling dietary supplement products.” This program will assist clinicians in providing better information to people with diabetes who use CAM supplements.

TESTING CAM SUPPLEMENTS

      An unfortunate situation is that most consumers believe that dietary supplements are evaluated for content and efficacy by an appropriate regulatory agency. The Harris Poll conducted 1,010 telephone interviews with a cross-section of adults in October 2002. The poll indicated that 68% of Americans believe the government requires herbal manufacturers to report potential dangers or adverse effects.⁵⁰ Additionally, 58% believed that government agencies, such as the FDA, must approve herbal products before sale to the public, and 55% believed that manufacturers cannot make claims for supplement safety or efficacy without scientific evidence. Additionally, 13% believed that because supplements are “natural” they are safe.⁵⁰ Actually, supplement manufacturers, not the FDA, are responsible for determination of safety and veracity of label claims. Most individuals do not realize that manufacturers do not have to tell the FDA or consumers what evidence they have about supplement safety or to back up their claims.⁵¹

      Accuracy of labeling and ingredient purity may now be assessed by different dietary supplement testing programs. Unfortunately, efficacy is not evaluated. An example of an organization that has established certification programs for dietary supplements is the U.S. Pharmacopeia (USP). The USP program is called the Dietary Supplement Verification Program.⁵² The “USP-verified mark” on the label indicates the product ingredients are accurate and that the product is pure, will dissolve properly, and has been manufactured using good manufacturing practices. Clinicians should note that the USP website also lists manufacturers that have undergone the evaluation process.⁵²

      NSF International (formerly known as National Sanitation Foundation) also verifies products for label and content accuracy, checks purity and contaminants, and audits the manufacturing process for good manufacturing practice compliance.⁵³ Consumer Lab also tests supplements.⁵⁴ It tests certain classes for purity and accuracy of labeled ingredient content. All of these companies require that manufacturers pay for testing.⁵⁵ The Consumers Union also tests certain products and reports findings in their publication, Consumer Reports.⁵⁶ The National Nutritional Foods Association (NNFA) has also launched a good manufacturing practice program. Recently, NNFA changed its name to the Natural Products Association, and more information may be obtained at their website.⁵⁷

EVALUATING CLAIMS FROM MANUFACTURERS OF DIETARY SUPPLEMENTS

      Manufacturers may use deceptive marketing tactics to promote their products. Clinicians may wish to access the FDA website that provides suggestions on “How to Spot Health Fraud.”⁵⁸ One caveat provided by the website is to be wary of a single product claiming benefit for a variety of unrelated diseases (for instance, difficulties ranging from menstrual СКАЧАТЬ