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Other common
name(s): clove oil, oil of cloves (Eugenol)
Scientific/medical
name(s): Syzygium
aromaticum, Caryophyllum
aromaticum, Eugenia
caryophyllata, Eugenia
aromatica
Description
The clove is an aromatic spice that grows as an evergreen tree
in the tropical regions of Asia and South America. The oil extracted
from the plant, leaves, flower buds, and fruit itself is used in herbal
remedies and some dental practices.
Overview
Available scientific evidence does not support claims that
cloves or clove oil is effective in treating or preventing cancer or
any other disease. Some dentists and patients report that clove oil may
relieve gum and tooth pain and may be useful as a topical antiseptic in
mouthwash; however, there is limited scientific evidence for this.
How is it promoted for use?
Some proponents also claim that cloves and clove oil, when
taken internally, relieve nausea and vomiting, improve digestion, fight
intestinal parasites, stimulate uterine contractions, ease arthritis
inflammation, stop migraine headaches, and ease symptoms of colds and
allergies. Practitioners of traditional Chinese medicine sometimes
treat hiccups and impotence with cloves (see our document Chinese Herbal Medicine).
Clove oil is also used in aromatherapy (see our document Aromatherapy).
Some practitioners claim that a mixture of cloves, black walnut hulls,
and wormwood can cure cancer (see our documents Black Walnut
and Wormwood).
What does it involve?
Cloves are available in capsules, powder, or as a whole herb.
Pure and diluted clove oil can also be purchased.
What is the history behind it?
Cloves and clove oil were reportedly used in Chinese medicine
as early as 600 AD. Cloves have long been a part of various folk
medicine traditions around the world. Clove oil has been used more
recently by some dentists, who swab it inside patients’
mouths to lessen the pain of anesthetic injections. People also applied
it inside the mouth to help toothaches. Today, cloves are also used as
an ingredient in baking and cooking and in perfumes, cigarettes,
mouthwash, and toothpaste.
What is the evidence?
Clove oil has been approved for use in dentistry as a topical
anesthetic by Commission E, Germany's regulatory agency for herbs.
However, no well-controlled clinical studies have been done to evaluate
the potential germ-killing and anticancer properties of cloves or clove
oil in humans. A small controlled study published in 2006 compared
clove gel to a numbing gel to lessen the pain of injections in the
mouth. The researchers found that people who were given a placebo gel
had more pain than those who received clove gel or numbing gel. The
pain levels of those who received the numbing medicine and those who
were given clove gel were about the same. Further studies are needed to
be sure this is a reliable effect.
Two recent laboratory studies do suggest that clove and clove
extracts may be antioxidants. Antioxidants are compounds that block the
action of free radicals, activated oxygen molecules that can damage
cells.
Very limited laboratory studies conducted in other countries
suggest that clove oil may fight bacteria and prevent seizures. One
recent study compared the oils from several herbs to find out how well
they stopped the growth of certain germs. Clove oil was very effective
at stopping the bacteria, yeasts, and molds that were tested. Along
these lines, a Japanese study in mice suggested that a clove
preparation taken by mouth might help reduce the severity of yeast
infections in the mouth.
A 2006 study suggested that cloves contain chemicals that
might reduce development of lung cancer in mice treated with
cancer-causing chemicals. Another laboratory study suggested that
compounds taken from cloves show promise as potential anticancer
agents. However, study results of clove extracts will not necessarily
be the same as studies using the raw plant. And, while laboratory
studies may show promise, further studies are needed to find out
whether the results apply to humans.
Are there any possible problems or
complications?
This product is sold as a
dietary supplement in the United States. Unlike companies that produce
drugs (which must provide the FDA with results of detailed testing
showing their product is safe and effective before the drug is approved
for sale), the companies that make supplements do not have to show
evidence of safety or health benefits to the FDA before selling their
products. Supplement products without any reliable scientific evidence
of health benefits may still be sold as long as the companies selling
them do not claim the supplements can prevent, treat, or cure any
specific disease. Some such products may not contain the amount of the
herb or substance that is written on the label, and some may include
other substances (contaminants). Though the FDA has written new rules
to improve the quality of manufacturing processes for dietary
supplements and the accurate listing of supplement ingredients, these
rules do not take full effect until 2010. And, the new rules do not
address the safety of supplement ingredients or their effects on health
when proper manufacturing techniques are used.
Most such
supplements have not been tested to find out if they interact with
medicines, foods, or other herbs and 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.
Cloves are generally considered safe, although a relatively
small number of people may be allergic to eugenol, their main active
ingredient. Severe reactions may occur in these people. Those known to
be allergic to clove or balsam of Peru should avoid using cloves in any
form, including inhaling the smoke from clove cigarettes.
Taking in large amounts of cloves or clove oil may cause
nausea, vomiting, abdominal pain, diarrhea, burns in the mouth and
throat, sore throat, seizures, difficulty breathing, rapid heartbeat,
sleepiness, intestinal bleeding, and liver or kidney failure. More
serious effects have been reported in young children, even with small
doses. Clove supplements may cause bleeding in those taking medicine to
stop blood clots (blood thinners). Use of clove supplements during
pregnancy is not recommended.
Excessive application of undiluted clove oil on or near the
teeth may cause irritation or damage to the gums or mouth and may
damage the dental pulp, the soft core of the tooth, made up of living
soft tissue and cells. It should be used for tooth and gum conditions
only under the supervision of a dentist. Undiluted clove oil may cause
skin irritation, rashes, or even burns.
Clove cigarettes, also known as kreteks, deliver more
nicotine, carbon monoxide, and tar than regular cigarettes. In addition
to having the same health risks as regular cigarettes, clove cigarettes
may also increase the risk of suddenly developing life-threatening
fluid buildup in the lungs, as well as serious pneumonia. 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
Abdel-Wahhab MA, Aly SE. Antioxidant property of Nigella
sativa (black cumin) and Syzygium aromaticum (clove) in rats during
aflatoxicosis. J Appl
Toxicol. 2005;25:218-223.
Alqareer A, Alyahya A, Andersson L. The effect of clove and
benzocaine versus placebo as topical anesthetics. J Dent.
2006;34:747-750.
Banerjee S, Panda CK, Das S. Clove (Syzygium aromaticum L.), a
potential chemopreventive agent for lung cancer. Carcinogenesis.
2006;27:1645-1654.
Clove (eugenia aromatica) and clove oil (eugenol). Aetna
InteliHealth Web site.
http://www.intelihealth.com/IH/ihtIH?d=dmtContent&c=351409.
Updated June 15, 2005. Accessed June 13, 2008.
Eugenol oil overdose. Medline Plus Web site.
www.nlm.nih.gov/medlineplus/ency/article/002647.htm. Accessed June 4,
2008.
Fetrow CW, Avila JR. Professional's
Handbook of Complementary & Alternative Medicines.
Philadelphia, PA: Lippincott Williams & Wilkins; 2004.
Gruenwald J. PDR
for Herbal Medicines. 3rd ed. Montvale, NJ: Thomson PDR;
2004.
Guidottii TL, Laing L, Prakash UB. Clove cigarettes. The basis
for concern regarding health effects. West J Med.
1989;151:220-228.
Lee KG, Shibamoto T. Inhibition of malonaldehyde formation
from blood plasma oxidation by aroma extracts and aroma components
isolated from clove and eucalyptus. Food Chem Toxicol.
2001;39:1199-1204.
López P, Sánchez C, Batlle R,
Nerín C. Solid- and vapor-phase antimicrobial activities of
six essential oils: susceptibility of selected foodborne bacterial and
fungal strains. J Agric
Food Chem. 2005;53:6939-6946.
Pérez C, Anesini C. Antibacterial activity of
alimentary plants against Staphylococcus aureus growth. Am J Chin Med.1994;22:169-174.
Popular natural remedies, part XVII. Wright State University
Pharmacy Web site.
http://www.wright.edu/admin/fredwhite/pharmacy/popular_nremedies17.html.
Accessed June 4, 2008.
Pourgholami MH, Kamalinejad M, Javadi M, Majzoob S, Sayyah M.
Evaluation of the anticonvulsant activity of the essential oil of
Eugenia caryophyllata in male mice.
J Ethnopharmacol. 1999;64:167-171.
Taguchi Y, Ishibashi H, Takizawa T, Inoue S, Yamaguchi H, Abe
S. Protection of oral or intestinal candidiasis in mice by oral or
intragastric administration of herbal food, clove (Syzygium aromaticum)
[Abstract]. Nippon
Ishinkin Gakkai Zasshi. 2005;46:27-33.
Zheng GQ, Kenney PM, Lam LK. Sesquiterpenes from clove
(Eugenia caryophyllata) as potential anticarcinogenic agents. J Nat Prod.
1992;55:999-1003.
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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