Neem is a compound that has a long history of use in both traditional Indian medicine and Ayurveda. Many of the popular herbal treatments in these two systems are still derived from it. Neem is a large evergreen tree, Azadirachta indica, in the mahogany family. It grows naturally in India and Sri Lanka, and has been successfully transplanted to other regions including West Africa, Indonesia, and Australia. The tree has small white flowers and produces a smooth, yellow-green fruit. All parts of the tree have medical uses. In India, neem is sometimes called "the village pharmacy." Over 100 pharmacologically active substances have been identified in this plant, and it has many traditional applications.
Neem's wide variety of reported benefits include use in the treatment of fever, gastrointestinal disease, dermatologic (skin) disorders, immune dysfunction, respiratory disease, parasites, inflammatory conditions, and infections by some bacteria, fungi, and viruses. Some components have been shown to have antimalarial properties. The seeds contain an insecticidal substance that is EPA approved for use on nonfood crops.
Some viral diseases have been treated by components of neem. It may inhibit the multiplication of viruses
Neem appears to be an appropriate treatment for numerous dermatologic indications. Its anti-inflammatory and pain relieving activity make it potentially useful against psoriasis, eczema, acne, dermatitis, and an assortment of fungal conditions. The neem leaf has been shown to have activity that suppresses the fungi that cause athlete's foot, ringworm, and Candida. Seed oil and aqueous leaf extracts have been used to treat jock itch, another fungal infection. The oil and leaf extract may be applied externally in the form of lotions and soaps. Leaf preparations may also be used internally for the detoxification properties. Poultices made from the leaf have antiseptic and astringent properties that treat wounds and boils.
Both internal and external parasites may be sensitive to the effects of neem. External parasites, such as lice and mites, are often treated in India with aqueous extracts of neem leaves. A medical research center in Nagercoil, India, found that a combination of neem and turmeric cured 97% of patients with scabies within 3–15 days of treatment. Teas are used against internal parasites, including intestinal worms. Perhaps one of the most interesting claims for neem is for the prevention and treatment of malaria. Leaf extracts are said to have the same effectiveness as quinine and chloroquine, the conventional medications that are used. Some studies show that even chloroquine-resistant strains of malaria are sensitive to neem, particularly a component called Irodin A. The recommended preventative measure is to chew and consume the leaves on a daily basis.
Twigs and leaves of the neem tree may be used for oral hygiene, and neem bark extracts used in toothpastes and mouthwashes are active against gingivitis. Ayurveda holds that neem has healthful properties for teeth and gum tissue.
Ayurvedic tradition holds that neem bark improves resistance to disease. It appears that certain carbohydrates contained in the bark do indeed stimulate the production of antibodies. One source recommends a cyclical use of neem to strengthen the immune system in order to lower the incidence of infections, particularly in people who have conditions that compromise the immune system.
Some studies show that neem can lower blood sugar levels. It has traditionally been used in Indian medicine
There are several components of neem that may make it valuable in the treatment of both osteoarthritis and rheumatoid arthritis. It is a proven anti-inflammatory that decreases histamine and other mediators of inflammation in the body. Some of the important chemicals in neem that contribute to this effect are nimbidin, limonoids, and catechin. Warmed neem oil is also recommended for external use to reduce pain and inflammation in affected joints.
Other claims for neem are extensive. They include treatment of high blood pressure, cholesterol, heart arrhythmia, kidney disorders, indigestion, anxiety, epilepsy, and many more. Some cancers may possibly be affected by the use of neem products. Consult a practitioner of Ayurveda or other expert in the use of botanicals for guidance in appropriate indications and products.
In addition to the treatment of human diseases and disorders, neem is being intensively studied as a natural insect repellent and pesticide. Studies in India and Pakistan have shown that it is an effective mosquito repellent. In 2002, the United States Department of Agriculture (USDA) reported that neem seed extract is toxic to the larvae of the Florida root weevil and other pests that attack citrus trees. As of 2000, 70 different patents had been granted for neem products intended for agricultural use.
Researchers in the textile industry are also finding uses for neem in the production of natural compounds for treating fabric. Neem seed hulls can be used to support the growth of fungi that produce an enzyme that will remove dye from cloth.
There are many forms and routes of use for neem. Some of the preparations include seed oil, aqueous extracts of the leaf, powder from the leaf, smoke from burning dried leaves, and leaf pastes. Topically, neem oil and leaf extracts are incorporated into some soaps and lotions for the treatment of skin conditions. These act to relieve inflammation and kill some of the infectious causes of conditions including acne and many fungi. A decoction of the bark is used externally for hemorrhoids. Some bark extracts are also especially bactericidal.
The directions for use and application of products vary depending on the formulation. Refer to the label information or consult a health care provider.
Due to a lack of sufficient study data and possible toxicity, it is inadvisable for children and pregnant or nursing women to use neem. Those who have impaired liver or kidney function should also use great caution. Large doses of seed or seed components may be toxic.
Traditional Ayurvedic practitioners advise against the use of neem if the patient suffers from obvious wasting or fatigue.
The long history of the use of neem in India appears to show that there is a low incidence of side effects when used appropriately. Infants have suffered severe sequelae, and even death as a result of internal use of neem. Avoid using neem products on children.
No clinically significant interactions between neem and other supplements or medications have been reported as of 2002.
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The Ayurvedic Institute. 11311 Menaul NE, Albuquerque, NM 87112. (505) 291-9698. <www.ayurveda.com>.
National Institute of Ayurvedic Medicine. 584 Milltown Road, Brewster, NY 10509. (845) 278-8700. <www.niam.com>.
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Rebecca J. Frey, PhD