Tea tree's therapeutic uses
Tea tree oil, derived from the leaves of the Melaleuca alternifolia plant, is recognized for its therapeutic applications, notably in treating skin-related conditions. Historically, its antiseptic properties were highlighted in the early 20th century, making it a staple in Australian medicine for wound care. Today, tea tree oil is popularly used as a natural remedy for various ailments, including dandruff, athlete's foot, acne, and oral herpes, although evidence for some uses remains limited.
Research indicates that tea tree oil can effectively combat fungal and bacterial infections on the skin, showing promise against conditions like athlete's foot and acne. For athlete's foot, studies have demonstrated that tea tree oil solutions can outperform placebo treatments, while its effectiveness for acne has also been substantiated in clinical trials. Additionally, it is believed to reduce dandruff symptoms when used in shampoo form.
While typically safe for topical use, tea tree oil can cause skin irritation in some individuals, highlighting the importance of starting with lower concentrations and performing patch tests. Furthermore, there are concerns about potential hormonal effects and toxicity if ingested. Overall, tea tree oil is a versatile natural alternative, but users should exercise caution and consult healthcare professionals for optimal results.
Tea tree's therapeutic uses
DEFINITION: Natural plant product used to treat specific health conditions.
PRINCIPAL PROPOSED USES: Dandruff, tinea pedis (athlete’s foot)
OTHER PROPOSED USES: Acne, oral herpes, periodontal disease, thrush, vaginal infections
Overview
Captain James Cook named this tree after finding that its aromatic, resinous leaves made a satisfying substitute for proper tea. One hundred fifty years later, an Australian government chemist, A. R. Penfold, studied tea tree leaves and discovered their antiseptic properties. Tea tree oil subsequently became a standard treatment in Australia for the prevention and treatment of wound infections. During World War II, the Australian government classified tea tree oil as an essential commodity and exempted producers of the oil from military service. However, the use of tea tree oil fell out of favor when antibiotics became widely available.
Therapeutic Dosages
Tea tree preparations contain various percentages of tea tree oil. For treating acne, the typical strength is 5 to 15 percent left on the skin for twenty minutes each day. For fungal nail infections, 70 to 100 percent tea tree oil should be applied each day for six months, but for athlete's foot, 25 to 50 percent oil is recommended for four weeks. For use as a vaginal douche (with medical supervision), 1 to 40 percent concentrations. To prevent methicillin-resistant Staphylococcus aureus (MRSA) colonization, a 5 percent concentrated body wash should be used daily.
Unless otherwise noted, tea tree oil is usually applied two to three times daily until symptoms resolve. However, tea tree oil can irritate the skin, so experts recommend that users start with low concentrations until they know their tolerance.
The best tea tree products contain oil from the alternifolia species of Melaleuca only, standardized to contain not more than 10 percent cineole (an irritant) and a minimum of 30 percent terpinen-4-ol. Oil from a specially bred variant of tea tree may have increased activity against microorganisms while irritating the skin less than the oil from other varieties.
Therapeutic Uses
Tea tree oil can kill many types of bacteria, viruses, and fungi on contact. This makes it an antiseptic, such as betadine, hydrogen peroxide, and many other essential oils. It is not an antibiotic, but it has antibacterial properties that may be useful on the skin.
Preliminary double-blind studies suggest that tea tree oil might be useful for athlete’s foot and other fungal infections of the skin and nails. One double-blind study found tea tree oil helpful for acne; another found that tea tree oil gel may reduce gum inflammation in people with periodontal disease. A single-blind study found evidence that tea tree oil may be helpful for dandruff.
Tea tree oil may be as effective as standard antiseptics for removing resistant strains of Staphylococcus bacteria, like MRSA, from the skin of hospitalized persons. This does not mean tea tree oil is effective as an antibiotic for staph bacteria. It is an antiseptic. Antiseptics work on the surface of the body, while antibiotics work from within.
Additionally, tea tree oil has been proposed as a treatment for vaginal infections, thrush, and oral herpes (cold sores). However, there is no reliable evidence to indicate that it is effective for these purposes.
Scientific Evidence
Athlete’s foot. In a double-blind, placebo-controlled trial, 158 people with athlete’s foot were treated with placebo, with 25 percent tea tree oil solution, or with 50 percent tea tree oil solution, applied twice daily for four weeks. The results showed that the two tea tree oil solutions were more effective than placebo at eradicating infection. In the 50 percent tea tree oil group, 64 percent were cured; in the 25 percent tea tree oil group, 55 percent were cured; in the placebo group, 31 percent were cured. These differences were statistically significant. A few participants developed dermatitis in response to the tea tree oil and had to drop out of the study, but most did not experience any significant side effects.
Another double-blind, placebo-controlled trial followed 104 people with athlete’s foot who were given either a 10 percent tea tree oil cream, the standard drug tolnaftate, or placebo. The results showed that tea tree oil reduced the symptoms of athlete’s foot more effectively than placebo but less effectively than tolnaftate. Neither treatment cured the infection in 100 percent of the cases, but each treatment cured many cases.
A third double-blind study followed 112 people with fungal infections of the toenails, comparing 100 percent tea tree oil to a standard topical antifungal treatment, clotrimazole. The results showed equivalent benefits; however, because topical clotrimazole is not regarded as a particularly effective treatment for this condition, the results mean little.
Dandruff. In a four-week placebo-controlled study of 126 people with mild to moderate dandruff, the use of 5 percent tea tree oil shampoo significantly reduced dandruff symptoms. However, this study was not double-blind: The researchers knew which participants received tea tree oil and which received the placebo. For this reason, the study’s results are not completely reliable. Further research and human trials are needed to confirm the efficacy of tea tree oil’s impact on dandruff, but it is a popularly used and relatively safe home remedy. Further, a 2022 study found tea tree oil successfully suffocated lice, particularly when combined with lavender oil.
Acne. The best evidence for the benefits of tea tree oil as a treatment for acne comes from a randomized, double-blind clinical trial of sixty people with mild to moderate acne symptoms. This study divided participants into two groups and treated them with a placebo or 5 percent tea tree oil gel. During the forty-five-day study period, researchers evaluated acne severity in two ways: by counting the total number of acne lesions and by rating acne severity on a standardized index. The results showed that tea tree oil gel was significantly more effective than the placebo at reducing the number and severity of acne lesions. Subsequent research in the twenty-first century continues to support these findings.
Safety Issues
When used topically, tea tree oil is thought to be safe. However, it can cause allergic inflammation of the skin, contact dermatitis, or increased sun sensitivity. It is advisable to test the oil on a small portion of the skin, wait a day, and then continue use to ensure severe reactions do not occur. Tea tree oil can be mixed with coconut or another oil before application to help limit irritation.
In addition, one report suggests that a combination of lavender oil and tea tree oil applied topically caused gynecomastia (male breast enlargement) in three young boys. The researchers who published this report also noted that testing of tea tree oil revealed estrogenic (estrogen-like) and antiandrogenic (testosterone-blocking) effects. However, a literature search failed to find any other published reports that corroborate this claim.
Like other essential oils, tea tree oil can be toxic if taken orally in excessive doses. The safety of tea tree oil use for young children, pregnant or nursing women, and those with severe liver or kidney disease has not been established. Individuals with eczema should avoid using tea tree oil.
Bibliography
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Blackwood, Bronagh, et al. “Tea Tree Oil (5%) Body Wash versus Standard Care (Johnson’s Baby Softwash) to Prevent Colonization with Methicillin-Resistant Staphylococcus Aureus in Critically Ill Adults: A Randomized Controlled Trial.” The Journal of Antimicrobial Chemotherapy, vol. 68, no. 5, 2013, pp. 1193–99, doi.org/10.1093/jac/dks501.
Carson, C. F., et al. “Melaleuca Alternifolia (Tea Tree) Oil Gel (6 Percent) for the Treatment of Recurrent Herpes Labialis.” Journal of Antimicrobial Chemotherapy, vol. 48, 2001, pp. 450-51.
Henley, D. V., et al. “Prepubertal Gynecomastia Linked to Lavender and Tea Tree Oils.” New England Journal of Medicine, vol. 356, 2007, pp. 479-85.
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Satchell, A. C., et al. “Treatment of Dandruff with 5 Percent Tea Tree Oil Shampoo.” Journal of the American Academy of Dermatology, vol. 47, 2002, pp. 852-55.
Soukoulis, S., and R. Hirsch. “The Effects of a Tea Tree Oil-Containing Gel on Plaque and Chronic Gingivitis.” Australian Dental Journal, vol. 49, 2004, pp. 78-83.
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