The Role of Quality Assurance and Standardization in the Safety of Botanical Dietary Supplements

The importance of complementary and alternative therapies such as botanical dietary supplements continues to increase throughout the world (1). The World Health Organization (WHO) has estimated that the majority of people in developing countries depend on traditional and herbal medicines as their primary source of health care (2). In the United States, 42% of the population have reported using complementary and alternative medicines, especially botanical dietary supplements (3), costing an estimated $5.1 billion per year (4). The marketing and use of dietary supplements has grown rapidly in the United States following the passage of the ‘Dietary Supplement and Health Education Act’ in 1994, which exempts dietary supplements from regulation as drugs providing that they are not marketed for the diagnosis, treatment, cure, or prevention of disease (5). Although the use of botanical dietary supplements has increased substantially during the last two decades, evidence for their efficacy and safety has not been well documented. In the United States for example, botanical dietary supplements are currently exempt from good manufacturing practice, do not require proof of efficacy, and do not require pre-marketing approval by the FDA unless drug-like claims are made. The safety of botanical dietary supplements is the responsibility of the manufacturers, and the role of the FDA in safety assurance is limited to post-marketing monitoring of adverse effects. Since no disease treatment or prevention benefits may be claimed for dietary supplements, they are exempt from FDA regulation, and efficacy studies for these products are relatively rare. Therefore, the safety and efficacy of most botanical dietary supplements lack documentation, which concerns many health care providers and consumers. Possible problems with botanical dietary supplements include contamination with pesticides, herbicides and heavy metals, contamination or adulteration with pharmacologically active medications, use of the incorrect part of the plants (for example, leaves instead of roots), and even misidentification of the plant species incorporated into the product. Since no toxicology studies are required for botanical dietary supplements, there is also concern that interaction might occur between botanicals and conventional pharmaceuticals or that metabolic activation of constituents in the botanical dietary supplement might result in the formation of toxic metabolites. The possibility of overdose is also an issue, since studies to establish maximum tolerated dosages and safe long-term chronic dosages are not required and are rarely carried out. Since botanical dietary supplements may be marketed until proven unsafe through the documentation of adverse effects, the safety of these products is determined primarily through self-regulation by manufacturers. Since consumers expect a consistent and safe product, the agricultural and herbal industries should work together to produce safe products of reproducible quality using basic principles of botany, chemistry and pharmacology. This review addresses basic safety issues concerning botanical dietary supplements. Specific problems that have occurred with respect to safety are described, and solutions to these safety issues are proposed.