How do these dangerous lapses occur? Because of the Dietary Supplement Health and Education Act, the FDA does not routinely analyze the contents of dietary supplements for their safety or efficacy. The manufacturer—not the government—is responsible for ensuring that the label is accurate and the ingredients are safe. Indeed, the FDA would have to prove that a supplement were unsafe in order to be allowed to remove it from the market.
LABELS AND CONTENTS
Although limited in its oversight, the FDA requires manufacturers of dietary supplements to follow certain guidelines when describing their products. For example, manufacturers of dietary supplements can make claims regarding the ability to maintain “structure and function” of the body, but cannot make claims regarding diagnosis, treatment, cure, or prevention of disease. 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 notify the FDA within 30 days after a product is on the market if it bears such a label.
The FDA also bans implied, as well as expressed, disease treatment claims. In other words, claims made by a manufacturer that a buyer could misconstrue as indicating treatment or prevention of a disease are no longer allowed. In new regulations, a product may make health maintenance claims but not disease treatment claims (i.e., “maintains a healthy prostate” is allowed, but “treats benign prostatic hyperplasia” is not).
The FDA requires that supplement labels (see Figure 1) contain certain information, so look for these details when you shop for products.
• Name of the product
• Name and address of the manufacturer
• Complete list of ingredients, including a “Supplement Facts” panel, which identifies each ingredient in the product. If an ingredient is not listed on the “Supplement Facts” panel, it must be listed in the “other ingredients” statement below the panel.
• Directions for use
• Net quantity of the contents
FIGURE 1.
Sample Supplement Label
Despite these requirements, the labels of dietary supplements can be confusing and misleading. A study of more than 800 bottles of popular herbs sold in retail stores found that over half the products were inconsistent in reporting benchmark ingredients and recommended daily doses.
In addition, the actual contents of products may not be reflected in the packaging. A study of the popular botanical Echinacea, which is taken to relieve cold symptoms, found numerous discrepancies in the ingredients listed on products. Ten percent of “Echinacea” products contained no measurable Echinacea.
INDEPENDENT TESTING
ORGANIZATIONS
Luckily, a handful of independent organizations accuracy Luckily, a handful of independent organizations test the accuracy of the labels and contents of dietary supplements. They offer “seals of approval” that you may want to look for when shopping for supplements. However, keep in mind that these organizations do not test the efficacy of products.
U.S. Pharmacopeia (USP) Dietary Supplement Verification Program
The “USP-verified mark” on the label indicates the label product ingredients are accurate and that the product is pure, will dissolve properly, and has been manufactured using good manufacturing practices. The USP website also lists manufacturers that have undergone the evaluation process (www.usp.org).
NSF International
Formerly known as National Sanitation Foundation, NSF International verifies the accuracy of supplement labels and contents, checks for purity and contaminants, and audits the manufacturing process for good manufacturing practice compliance (www.nsf.org).
Consumer Lab
Consumer Lab tests supplements for the accuracy and purity of their ingredients (www.consumerlab.com).
The Consumers Union
The Consumers Union also tests certain reports findings in its publication, Consumer Reports www.consumerreports.com ; subscription required for some content).
The Natural Products Association
The Natural Products Association has launched a good manufacturing practice program (www.naturalproductsassoc.org).
SIZING UP THE PRODUCT AND MANUFACTURER
It’s best to use a dietary supplement that comes in a pure, standardized form. You can check the purity of a product by consulting the United States Pharmacopoeia (www.usp.org). You’ll also want to purchase products from large, nationally known companies. These companies are more likely to incorporate good manufacturing practices and stringent quality assurance.
If you have questions about a product, you may want to contact the manufacturer directly. The manufacturer should be able to answer the following questions:
• Has your product been evaluated in scientific studies that have been published in reputable medical journals? If so, are you willing to share these studies? Or, is most of the product information the result of testimonials by people with diabetes who have used the product?
• Can you explain how the product works? Do you have scientific studies that verify the mechanism of action?
• Does your company conduct a chemical analysis of the active and inactive ingredients to verify that the product contains what it says on the label?
• Does the product break down and dissolve appropriately in the stomach?
• Does your company specify specific storage or stability instructions, such as what temperature to store the product, whether light may affect the product, or whether it should be stored in a dark place? Do you list an expiration date for the shelf life of the product?
• Do you specify any side effects or possible interactions with other supplements or prescription drugs or disease states? Do you specify which patients should not use the product?
Even when armed with these questions and the best intentions, consumers may find it difficult to evaluate the safety and efficacy of products. Unfortunately, many of the scientific studies done on dietary supplements are unreliable. For example, studies may include only small numbers of patients. Some scientists never examine the actual contents of the studied products, so their results could be unintentionally skewed. For these reasons and others, the Natural Standard, an independent group of scientists who evaluate complementary and alternative medicines, has given most dietary supplements for diabetes a grade “B” or lower in terms of efficacy.
In Part II, you’ll find summaries of the best studies done on each individual supplement, as well as tips for evaluating the results. Keep in mind that some supplements have been more rigorously studied than others. It’s always best to talk with you health care provider about questions regarding the efficacy and safety of product, rather than trying to troubleshoot on your own.
HOW MUCH SHOULD YOU TAKE?
The National Academy of Sciences provides information reference daily intake (RDI) for many—but not all—vitamins and minerals. Most other dietary supplements, such as herbs, do not have recommended daily allowances. In fact, the appropriate doses of many dietary supplements are unknown. In Part II, you’ll find the available information on recommended doses for individual supplements.