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Other common
name(s): greasewood, creosote bush
Scientific/medical
name(s): Larrea divericata coville,
Larrea tridentata (DC)
coville
Description
Chaparral is an herb that comes from the leaves of the
creosote bush, an evergreen desert shrub. The term "chaparral" refers
to a group of plants dominated by evergreen shrubs that have small,
stiff leaves and grow in dense clusters to heights of 4 to 8 feet in
the American West and Southwest.
Overview
Chaparral is considered a dangerous herb that can cause
irreversible, life-threatening liver damage and kidney damage. The U.S.
Food and Drug Administration (FDA) has cautioned against the internal
use of chapparal. Research has not found it to be an effective
treatment for cancer or any other disease. A study of
nordihydroguaiaretic acid (NDGA), one of the chemicals in chaparral,
concluded that it was not useful in treating people with cancer,
although studies continue.
How is it promoted for use?
Proponents claim that chaparral can help relieve pain, reduce
inflammation, aid congestion, increase urine elimination, and slow the
aging process. It is also promoted as an anti-cancer agent and an
antioxidant (a compound that blocks the action of free radicals,
activated oxygen molecules that can damage cells).
Some researchers think NDGA might make other anti-cancer drugs
more effective, but this theory still needs to be tested through animal
studies and clinical trials of people who have cancer.
What does it involve?
Chaparral is distributed in capsule or tablet form. Chaparral
also can be made into a bitter and unpleasant-tasting tea or a
tincture, a solution of chemicals from chaparral leaves dissolved in
alcohol. Chaparral is also sometimes found with other herbs in a
variety of teas.
What is the history behind it?
Native Americans used chaparral as an herbal remedy. They
heated the leaves and applied them to the skin to treat wounds,
bronchitis, coughs skin disorders, venereal sores, warts, blemishes,
and ringworm. Heated stems were inserted into tooth cavities to relieve
pain, and the leaves and stems were boiled to make tea to relieve
rheumatism and other conditions, including colds, bronchitis, digestive
problems, and cancer.
According to anecdotal reports, chaparral tea was used widely
in the United States from the late 1950s to the 1970s as an alternative
anti-cancer agent. Experimental studies in the 1960s showed that
chaparral could cause problems with kidney and liver function. The
growth of interest in alternative medicine led to increased use of
chaparral in the 1980s. By the early 1990s, there had been many reports
of chaparral-linked illnesses, and the FDA issued a warning, resulting
in the voluntary removal of many chaparral products from stores.
Despite many concerns and warnings, chaparral has become more readily
available again and is still advertised and sold on the Internet.
What is the evidence?
Available scientific evidence does not support the idea that
chaparral can prevent or slow the growth of cancer in humans, nor does
it support chaparral as effective in treating other medical conditions.
Some preliminary laboratory studies have indicated that one of the
chemicals in chaparral, NDGA, may possess anti-cancer properties.
However, available scientific evidence has not confirmed these
findings.
Studies of NDGA have had conflicting results. According to a
1990 government report, some researchers reported that NDGA inhibited
cancer growth in animals. Others found that low levels of NDGA actually
stimulated the growth of some types of tumor cells, although higher
concentrations had the opposite effect. More recent cell culture
studies using cancer cells grown in the laboratory suggest NDGA may
make other anticancer drugs more effective, and researchers continue to
look into the potential uses of purified NDGA. While these studies show
some promise, further studies would be necessary to determine whether
the results apply to humans.
In 1970, researchers from the University of Utah published
results of a clinical study sponsored by the National Cancer Institute
on chaparral tea and NDGA. People with advanced, incurable cancer drank
chaparral tea or took doses of pure NDGA by mouth. Of the 45 people who
were evaluated, 4 experienced a decrease in the size of their tumors.
The regression lasted between 10 days and 20 months. However, tumors
grew larger in others treated with chaparral. Overall, the authors
concluded that chaparral tea was not an effective anticancer agent.
One case study reported that severe hepatitis developed in a
60-year-old woman who had taken chaparral for 10 months. She eventually
required a liver transplant. In a later review of 18 case reports of
adverse reactions associated with taking chaparral, researchers
concluded that the herb is linked with irreversible liver damage and
liver failure.
Are there any possible problems or
complications?
This substance
may not have been tested to find out how it interacts with medicines,
foods, herbs, or supplements. Even though some reports of interactions
and harmful effects may be published, full studies of interactions and
effects are not often available. Because of these limitations, any
information on ill effects and interactions below should be considered
incomplete.
Although chaparral is still widely available, the FDA has
recommended since 1968 that it not be taken internally. Chaparral is
highly toxic and has been reported to cause severe and permanent liver
disease that can be fatal. It has also been linked to kidney damage,
including cysts in the kidney and kidney failure.
Chaparral may cause dangerous interactions with a number of
other medicines and herbs. Blood-thinning medications (anticoagulants);
non-steroidal anti-inflammatory medicines (pain medicines such as
aspirin, ibuprofen, naproxen, and others); antidiabetic drugs; and
certain antidepressants (MAO inhibitors) are thought to be likely to
cause problems while taking chaparral. Always tell your doctor and
pharmacist about any herbs you are taking.
Other side effects of chaparral can include fatigue, stomach
pain, diarrhea, weight loss, fever, itching, rash, and allergic
reactions. This herb should be avoided, especially by women who are
pregnant or breast-feeding. Relying on this type of treatment alone and
avoiding or delaying conventional medical care for cancer may have
serious health consequences.
Additional Resources
More information from your American Cancer
Society
The following information on complementary and alternative
therapies may also be helpful to you. These materials may be found on
our Web site (www.cancer.org)
or ordered from our toll-free number (1-800-ACS-2345).
References
Chaparral (Larrea tridentata (DC) Coville, Larrea divaricata
Cav) & Nordihydroguaiaretic acid (NDGA). Medline Plus Web site.
http://www.nlm.nih.gov/medlineplus/druginfo/natural/patient-chaparral.html.
Accessed April 12, 2007. Content no longer available.
Chaparral. Memorial Sloan-Kettering Cancer Center Web site.
http://www.mskcc.org/mskcc/html/69175.cfm. Accessed June 4, 2008.
Ding XZ, Kuszynski CA, El-Metwally TH, Adrian TE. Lipoxygenase
inhibition induced apoptosis, morphological changes, and carbonic
anhydrase expression in human pancreatic cancer cells. Biochem Biophys Res Commun.
1999;266:392-399.
Fetrow CW, Avila JR. Professional's
Handbook of Complementary & Alternative Medicines.
Philadelphia, PA: Lippincott Williams & Wilkins; 2004.
Gordon DW, Rosenthal G, Hart J, Sirota R, Baker AL. Chaparral
ingestion. The broadening spectrum of liver injury caused by herbal
medications. JAMA.
1995;273:489-490.
Natural Standard. Herbal/plant therapies: chaparral (larrea
tridentata (dc) coville, larrea divaricata (cav) &
nordihydroguaiaretic acid (ndga). Complementary/Integrative Medicine
Education Resources, The University of Texas M.D. Anderson Cancer
Center Web site.
http://www.mdanderson.org/departments/cimer/display.cfm?id=5A5EF4F0-CF19-4FD1-9B40FD8546A616D9&method=displayFull.
Accessed June 4, 2008.
Sheikh NM, Philen RM, Love LA. Chaparral-associated
hepatotoxicity. Arch
Intern Med. 1997;157:913-919.
Smart CR, Hogle HH, Vogel H, Broom AD, Bartholomew D. Clinical
experience with nordihydroguaiaretic acid -- "chaparrel tea" in the
treatment of cancer.
Rocky Mt Med J. 1970;67:39-43.
Soriano AF, Helfrich B, Chan DC, Heasley LE, Bunn PA Jr, Chou
TC. Synergistic effects of new chemopreventive agents and conventional
cytotoxic agents against human lung cancer cell lines. Cancer Res.
1999;59:6178-6184.
US Congress, Office of Technology Assessment. Unconventional Cancer
Treatments: OTA-H-405. Washington, DC: US Government
Printing Office; 1990.
Note:
This
information may not cover all possible claims, uses, actions,
precautions, side effects or interactions. It is not intended as
medical advice, and should not be relied upon as a substitute for
consultation with your doctor, who is familiar with your medical
situation.
Last Medical Review: 11/01/2008
Last Revised: 11/01/2008
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