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Information on Herbs
- For Consumers
- For Health Professionals
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Annotated Bibliography

Links

North Carolina Consortium on Natural Medicines

Aren’t herbal products safer than pharmaceutical drugs because they are made from natural ingredients?

While the pharmaceutical industry has made important progress in recent decades in developing reliable, effective medications, the emphasis on proving efficacy has often overshadowed safety issues. So, despite federal drug regulations, serious safety problems related to pharmaceutical drugs persist. For example, one in five patients seen in a clinic experiences serious side effects, mainly from antibiotics, antidepressants, and anti-inflammatory drugs.(1)

Herbal products, although made from natural substances, are the forerunners of synthetic prescription drugs. Up to 25% of medications are derived directly or indirectly from naturally-occurring chemicals from plants, bacteria and fungi, or marine organisms. Like medications, herbal products have a biological action, which is why, in Europe, many herbal products are regulated as drugs.

Many herbal products are quite safe and fall into the realm of foods. Examples include gentle herbs, like chamomile and mint, and many of the western “tonic” herbs traditionally consumed as teas, such as nettles and green oats. Many of the herbs commonly used in cooking, have specific indications for the treatment of health conditions. For example, dill reduces gaseousness and colic in children, parsley has mild diuretic action (reduces excess fluid in the body), and ginger may reduce nausea.(2)

A few other herbs, termed “heroics”, have a history of adverse effects well-known to traditional herbalists and have been used specifically because of their toxic properties. (3) An example may be the use of bloodroot for treating skin cancers as popularized by Frederick Mohs, M.D.(4)
Most commonly used herbal products have both biological action and a low incidence of adverse effects and side effects.

Legislation is pending currently in Congress that would institute an adverse drug reaction tracking mechanism for herbal products similar to that used to monitor prescription drugs. This systematic approach should permit a better risk-benefit assessment of specific herbal products.

How do I choose herbal products of good quality?

Consumers and health professionals are concerned about variable quality control. They need to know that the product contains the components shown on the label in the listed amounts, and nothing else. Well-publicized cases of contamination of herbal products frequently surface in the news. Herbal products may pose a risk from contamination with pesticides, heavy metals (cadmium, mercury), pharmaceuticals, and micro-organisms.(5) In addition, products containing a misidentified, look-alike herb with toxic propertie, have caused many of the serious adverse reactions related to herbal products.(3)

The Food and Drug Administration (FDA) and private organizations are addressing some of the problems associated with herbal products. The FDA published Good Manufacturing Practices (GMP) in 2003.(6) More recent FDA initiatives include a rating system for the evaluation of scientific evidence and a guideline for presenting this evidence to the FDA.(7,8)

Private organizations have taken on the task of certifying manufacturers that are following good manufacturing practices. These organizations are also developing standards for herbal product quality that will prompt manufacturers to test their products for species identification, constituent composition, and contamination by heavy metals, micro-organisms, and extraneous substances.(9) Further, NSF/ANSI (American National Standard for Dietary Supplements) standards require that each unit of herbal product can be traced with a batch number corresponding to the afore-mentioned quality testing.

Currently, four organizations conduct independent analysis of herbal products: ConsumerLab.com, National Nutritional Foods Association, NSF International, and the United States Pharmacopeia:

1) ConsumerLab.com (CL) tests products off the shelves and at the request of manufacturers. Results are published on their website and in their book, ConsumerLab.com’s Guide to Buying Vitamins and Supplements: What’s Really in the Bottle? (9)

2) The National Nutritional Foods Association (NNFA) is a trade group that has a GMP certification process and a “TruLabel” process that tests for ingredient quality and contaminants. Products that meet NNFA’s Trulabel standards are published on their free website: http://www.nnfa.org Manufactureres that qualify for GMP certification may publish the GMP logo on their label.(9)

3) NSF is a non-profit public health organization with a long history of independent certification of food products through random testing.(9)
Consumers can find the NSF label on certified herbal products or can look up a product on their website at http://www.nsfconsumer.org/food/dietary_supplements.asp

4) The United States Pharmacopeia (USP) also has a program of independent testing of dietary supplements. Results of their evaluations can be found free of charge at www.uspverified.org In addition to testing for contamination, adulturation, and good manufacturing processes, USP also examines products for pharmacologic properties, such as how well the products break down in the stomach.(9)

Can herbs interact with pharmaceutical drugs?

Yes, indeed. The potential for some herbs to impact the effectiveness of conventional medications is one of the important issues facing health care practitioners today. After all, one in six adults taking prescription drugs also takes at least one herbal product.(10) While some interactions are immediately apparent, other, more subtle problems may result over time. An herbal product might counteract a medication, dilute its effects, or enhance its properties, creating an inadvertent “overdose.” Often the effect is not obvious and may thus compound over time. For example, St. John’s Wort, a popular herbal remedy for depression, may decrease the effectiveness of anti-rejection drugs in transplant patients and antiviral drugs in HIV patients, with dire consequences. (11,12) If taken for longer than 14 days, St John’s Wort also alters the metabolism of other conventional medications by affecting liver enzyme function.(13)

Where do I find information about drug-herb interactions?

Please see the annotated bibliography for a list of useful references and links to websites. In addition, Herb Contraindications and Drug Interactions by Francis Brinker, N.D. is now available in an updated third edition. Brinker’s compilation of herb-drug interactions could help a busy health professional determine if her patient’s use of herbs should be a source of concern.

Other sources of information include your local Drug Information Center. Here in North Carolina, we are fortunate to have experts in herbal therapies available to help answer questions regarding herb safety and drug-herb interactions. Joe and Terry Graedon of The People’s Pharmacy host a weekly radio show in which they take calls from consumers regarding drugs, dietary supplements, and home remedies. You can contact Joe and Terry through their website at http://www.healthcentral.com/peoplespharmacy/peoplespharmacy.cfm

If I have a symptom I think may be related to an herbal product I have been taking, what should I do?

If the symptom is unpleasant, the first step is to discontinue the use of the product and take notes about your symptoms. Record the time the symptoms started and what you were doing at that time. What other drugs or supplements were you taking then? Were you exposed to to any other potentially noxious agents, such as chemicals or chemical fumes, perfumed products, or pesticides when the symptoms began? Be sure to take your notes and any remaining herbal or dietary supplement product (including any labeling or identifying information such as the manufacturer’s address, lot number, etc.) to show to your health care provider. Your doctor or pharmacist may be able to help you determine if the symptoms are related to the product, to an interaction with one of your medications, or to some other exposure.

If the reaction is serious, please report it (or ask your health care provider to report it) to either your local poison control center or to the FDA’s MedWatch system. You can dowload a MedWatch reporting form from the FDA at http://www.fda.gov/medwatch/getforms.htm
You can also call the FDA for information at 1-888-463-6332.

For unexpected positive events associated with an herbal product or dietary supplement, again please take notes. You can discuss your findings with your healthcare professional or contact The People’s Pharmacy at http://www.healthcentral.com/peoplespharmacy/peoplespharmacy.cfm

References
1. Gandhi T. K., Burstin H. R., Cook E. F., Puopolo A.L., Haas J.S., Brennan T.A. and Bates D. W. (2000): Drug complications in outpatients. Journal of General Internal Medicine. 15:149-154.
2. Hoffman David (2003): Medical Herbalism. Rochester, Vermont, Healing Arts Press
3. Mills S. and Bone K. (2000): Optimizing safety, in Mills S, Bone, K: Principles and practice of phytotherapy. Philadelphia, Harcourt Publishers Limited, pp p.103.
4. Alleger Irene (1999): Cancer Salves: A Botanical Approach to Treatment., Townsend Letter Group: Townsend Letter for Doctors & Patients, pp 142.
5. Slifman N. R., Obermeyer W. R., Aloi B. K., Musser S. M., Correll W. A., Jr., Cichowicz S. M., Betz J. M. and Love L. A. (1998): Contamination of botanical dietary supplements by Digitalis lanata. N Engl J Med. 339(12): 806-11.
6. FDA (2003): Current good manufacturing practice in manufacturing, packing, or holding dietary ingredients and dietary supplements, Food and Drug administraion, HHS. Accessed: 6/23, http://www.cfsan.fda.gov/~lrd/fr030313.html
7. CFSAN (2004): Substantiation for dietary supplement claims made under Section 403(r) (6) of the Federal Food, Drug, and Cosmetic Act. College Park, MD, Food and Drug Administration. Accessed: 11/15, http://www.cfsan.fda.gov/~dms/dsclmgui.html
8. --- (2004): Interim evidence-based ranking system for scientific data: guidance for Industry and FDA. College Park, MD, Food and Drug Administration. Accessed: 11/15,
9. Whybark Marie K. (2004): Third-party evaluation programs for the quality of dietary supplements. HerbalGram. 64(November): 30-33.
10. Kaufman D. W., Kelly J. P., Rosenberg L., Anderson T. E. and Mitchell A. A. (2002): Recent patterns of medication use in the ambulatory adult population of the United States: the Slone survey. Jama. 287(3): 337-44.
11. Mannel M. (2004): Drug interactions with St John's wort : mechanisms and clinical implications. Drug Saf. 27(11): 773-97.
12. Barone G. W., Gurley B. J., Ketel B. L. and Abul-Ezz S. R. (2001): Herbal supplements: a potential for drug interactions in transplant recipients. Transplantation. 71(2): 239-41.
13. Wang S. M., Peloquin C. and Kain Z. N. (2002): Attitudes of patients undergoing surgery toward alternative medical treatment. J Altern Complement Med. 8(3): 351-6.