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Dietetic Internship

Food For Thought

Christine Noviello 

Ephedra:  Its Use As A Dietary Supplement 
The increase in the use of plant-derived medications and dietary supplements, such as ephedra, has raised health issues.  Patients do not tell their health care providers about herbal medications because they feel they are not “real” drugs and that natural products are safer than prescribed medications (1).

In recent years there has been an increase in the interest of ephedra as an appetite suppressant.  Ephedra is a plant derivative that contains ephedrine and pseudoephedrine that can raise blood pressure and heart rate.  The U.S. Food and Drug Adminstration (FDA) has documented 800 cases of adverse effects, such as heart attack, stroke, tremors, insomnia, and at least 17 deaths associated with the use of ephedra (2).

Dietary Supplement 
A dietary supplement is any product taken by mouth that contains a dietary ingredient and is clearly stated on the label that it is a dietary supplement.  Some examples of dietary ingredients are:  vitamins, minerals, herbs, and amino acids.  Dietary supplements can be found in pills, tablets, capsules, liquids, or powders (3).  There are many side effects and also possible drug interactions associated with the use of prescription medications with dietary supplements (1).

Herbal products do not have to be proven safe or effective before marketing because they are not marketed for the prevention, diagnosis, cure, treatment, or mitigation of a disease.  They are classified as “dietary supplements” and are marketed according to the Dietary Supplement Health and Education Act of 1994 (DSHEA).  The DSHEA allows herbal labeling to carry claims regarding the product’s ability to affect the structure or function of the human body or to promote general well being but they cannot use the word “cure”.  The FDA passed a rule on March 23, 1999 that requires an information panel to be on the label of dietary supplements titled “Supplement Facts”.  The information should include:  the herb’s common, usual, or botanical name; the part of the plant used to make the product; the suggested serving size; amount per serving; and any nutrients in the product (4).

Ephedra
Ephedra, also known for a plant traditionally called ma huang, meaning “yellow astringent” in Chinese, is one of the world’s oldest plants and a distant relative of two other ancient and well-known medicinal plants-ginkgo and horsetail.  Ephedra consists of about 40 species in which the most popular commercial species are Ephedra sinica and E.equisetina which are from China (5).  Used for more than 4,000 years in China to treat symptoms of asthma and upper respiratory infections, ephedra is used today in many over-the-counter cold and allergy medications as well as weight loss and energy products (6).

Ephedra consists of two naturally occurring alkaloids, ephedrine and pseudoephedrine.  The two alkaloids have opposite effects on the body that help balance each other (1).  Ephedrine, the main constituent, is a bronchodilator and stimulates the central nervous system, raising heart rate and blood pressure.   Pseudoephedrine is a nasal decongestant and is less stimulating on the heart and blood pressure (6).

Ephedra’s stimulant effect is compared to that of amphetamines, although it is only one fifth as strong.  Ephedrine stimulates the release of noradrenaline from the sympathetic nervous system, forcing more blood to the brain and limbs (5).

Use In Weight Loss 
Because of ephedrine’s effect on the stimulation of the nervous system it is used for appetite suppression.  It stimulates the thyroid gland, thereby promoting metabolism (6).  The thermogenic affect increases basal metabolic rate, slightly raising body temperature and causing calories to be burned at a faster rate (7).

Research suggests that adding caffeine to ephedrine increases thermogenesis, weight loss, or fat loss in obese individuals by centrally suppressing appetite and peripherally stimulating fat oxidation (2).  Many herbal manufacturers add caffeine to their appetite suppressants by adding herbs that contain caffeine such as guarana seeds or kola nuts (7). 

Ephedra was found in studies to stimulate weight loss in certain overweight people who have a physiological problem that impairs their ability to burn fat.  A 1997 study in the American Journal of Physiology

concluded that exercise may stimulate metabolism as effectively or better than ephedra without the negative side effects.  Ephedra can also worsen a dieter’s mood because it stimulates adrenaline secretion leading to a “stressed-out” syndrome that weakens adrenal gland function (5).

Ephedra’s Side Effects 
Ephedra increases both systolic and diastolic blood pressure as well as heart rate.  Other side effects may be nervousness, headache, insomnia, and dizziness.  As a result of the side effects, persons suffering from heart conditions, hypertension, diabetes, or thyroid disease should use ephedra with caution (8).

A study in the New England Journal of Medicine reviewed 140 reports of adverse events related to the use of dietary supplements containing ephedra alkaloids between June 1, 1997 and March 31, 1999.  The results concluded that 31 percent of the cases were definitely or probably related to the use of ephedrine and 31 percent were possibly related to ephedra use.  Adverse effects included hypertension, palpitations, tachycardia, stroke, seizures and deaths.  The authors concluded that ephedra alkaloids in dietary supplements pose a serious health risk to some users, indicating the need for appropriate dosing guidelines and warnings (9).

A study in The American Journal of Health System Pharmacology tested twenty herbal dietary supplements containing ephedra for the ephedra alkaloid content in each supplement.  Half of the supplements tested had discrepancies between the label claim for ephedra alkaloid content and the actual content in excess of 20 percent.  One product did not have any ephedra alkaloids.  Several of the dietary supplements tested showed an inconsistency in the alkaloid content in the product as compared to that on the product’s label (10).

Drug Interactions 
Drug interactions are unpredictable and complex, which makes the use of dietary supplements with prescription medications risky and complex for clinicians to manage (1).

Ephedra should not be combined with oxytocin because the combination can cause severe hypertension (1).  Monoamine oxidase inhibitors (MAOI), theophylline (used in respiratory diseases), and caffeine can increase blood pressure, heart rate, and central nervous system stimulation when used in combination with ephedra (1,5). Anti-hypertensives combined with ephedra can have antagonistic effects (1).

In summary, ephedra or ma huang is a dietary supplement used in many over-the-counter weight loss products.  Ephedra claims to suppress the appetite and stimulate metabolism leading to weight loss.  Because it has a stimulation effect, many side effects are associated with ephedra especially in combination with caffeine.  Consumers choosing weight-loss products should read labels and look for products without ephedra or ma huang and inform their clinicians if they are taking any dietary supplements.

References

  1. Shah, P. and Grant, K.  An Overview of Common Herbal Supplements. Support Line.  2000;22(5):3-18.
  2. Ling, N.  Metabolism Boosters.  Today’s Dietitian.  2001;3(1):29-31.
  3. FDA/CFSAN, Office of Special Nutritionals:  Overview of Dietary Supplements:  www.cfsan.fda.gov
  4. Cupp, M.J.  Toxicology and Clinical Pharmacology of Herbal Products. Totowa, NJ:  Humana Press Inc.; 2000. 
  5. McCaleb, R., Leigh, E., and Morien, K. Encyclopedia of Popular Herbs. 2000.
  6. Herbal Information Center and Vitamin Directory:  www.kcweb.com
  7. MetaboMax:  www.a-better-way.com
  8. Tyler, V. The Honest Herbal.  The Haworth Press, Inc.; 1993.
  9. Haller, C. and Benowitz, N. Adverse Cardiovascular and Central Nervous System Events Associated With Dietary Supplements Containing Ephedra Alkaloids.  New England Journal of Medicine.
  10. May 2000;343(25):1833-8.
  11. Gurley, BJ., Gardner, SF., and Hubbard, MA.  Content Versus Label Claims In Ephedra-Containing Dietary Supplements.  American Journal of Health System Pharmacology.  May 2000; 57(10):963-9.