by Richard Glickman-Simon, MD
It used to be that food was food and drugs were drugs. Nowadays, its not always easy to tell them apart. Consumers are faced with a great variety of products
The nature of dietary supplements
Dietary supplements are edible products that contain one or more substances
A closer look at safety
DSHEA also allows lower safety standards for dietary supplements. Manufacturers need only show that their product is "reasonably expected to be safe," but DSHEA does not specify what evidence is required to make this safety assertion. In addition, once a product is on the market, it is up to the government to show that it is unsafe and that it should be withdrawn. Such a withdrawal is called a post-market recall. These recalls do occur with drugs as well, but many consumer-advocacy groups claim that the public is at greater risk with dietary supplements because they do not undergo the stringent pre-market scrutiny that drugs do.
Still, others argue that comparable vigilance is not necessary for these "natural" products, which are often gentler and less toxic than highly concentrated, chemically based drugs. While this may be true, "natural" does not mean "safe." Plants, after all, produce some of the most powerful poisons on earth. Furthermore, studies suggest that up to 20% of patients taking prescriptions drugs also take dietary supplements. So even if a supplement is considered safe, it can still interfere with the function of other medications a patient is taking.
Buyer beware
Another issue closely related to safety and effectiveness is the concentration and purity of the product. When you purchase an FDA-approved drug, you know exactly what youre getting, down to the last milligram.
This is not always true of dietary supplements. Herbs, in particular, often contain many different constituents in addition to the active ingredient. In fact, studies have shown that some supplements contain no active ingredients at all, while others contain much higher concentrations than the label indicates. It is also not uncommon for supplements to contain substances that are not listed on the label, some of which may be biologically active.
Currently, the government is not responsible for assuring that whats on the label of a dietary supplement is actually in the bottle.
Still considering dietary supplements?
Given all this ambiguity, is it possible to safely take a dietary supplement and expect a positive result? Yes it is.
By adhering to a few simple rules and doing some homework ahead of time, this vast and perplexing marketplace need not be so daunting. Part two of this article (April 2002) will provide you with a step-by-step guide to purchasing dietary supplements.