Lemongrass (Cymbopogon citratus)
A tropical grass native to southern India and Sri Lanka, yielding an aromatic oil used as flavoring and in perfumery and medicine.
Resembling a gigantic weed, lemongrass is an aromatic tropical plant with long, slender blades that can grow to a height of 5 ft (1.5 m). Believed to have a wide range of therapeutic effects, the herb has been used for centuries in South America and India and has also become popular in the United States. Aside from folk medicine, lemongrass is a favorite ingredient in Thai cuisine and dishes that boast a tangy, Asian flavor. While there are several species of lemongrass, Cymbopogon citratus is the variety most often recommended for medicinal purposes. Native to Southeast Asia, lemongrass can also be found growing in India, South America, Africa, Australia, and the United States. Only the fresh or dried leaves of lemongrass, and the essential oil derived from them, are used as a drug. Cymbopogon citratus, which belongs to the Poaceae family of plants, is also referred to as West Indian lemongrass.
Not to be confused with lemon balm, which is an entirely different herb, lemongrass is considered by herbalists to have several useful properties, including antibacterial, antifungal, and fever-reducing effects. Some of these claims have been supported by animal and laboratory studies. In one test-tube investigation, published in the medical journal Microbios in 1996, researchers demonstrated that lemongrass was effective against 22 strains of bacteria and 12 types of fungi. Scientific research has also bolstered the herb’s reputation as an analgesic and sedative. A study conducted in rodents suggests that myrcene, a chemical found in the essential oil of Cymbopogon citratus, may act as a site-specific pain reliever. Unlike aspirin and similar analgesics, which tend to alleviate pain throughout the body, myrcene seems to work only on particular areas. A study involving people indicates that lemongrass may also affect the way the body processes cholesterol.
More recently, lemongrass has been shown to have antimutagenic properties; that is, researchers have found that it is able to reverse chemically induced mutations in certain strains of bacteria.
While they may not be aware of it, most Americans have already tried lemongrass in one form or another. Citral, a key chemical found in Cymbopogon citratus, is an ingredient in a variety of foods and beverages (including alcohol). It can be found in candies, puddings, baked goods, meat products, and even in certain fats and oils. Citral is a pale yellow liquid that evaporates rapidly at room temperature. Like other essential oils, lemongrass is also used as a fragrance enhancer in many perfumes, soaps, and detergents.
While not approved by the Food and Drug Administration (FDA), lemongrass reportedly has a wide variety of therapeutic effects. Because the herb has not been studied extensively in people, its effectiveness is based mainly on the results of animal and laboratory studies as well as its centuries-old reputation as a folk remedy. Lemongrass is one of the most popular plant medicines in Brazil, where it is used to treat nervous disorders and stomach problems. In the Amazon, lemongrass is highly regarded as a sedative tea.
When taken internally, lemongrass has been recommended for stomachaches, diarrhea, gas, bowel spasms, vomiting, fever, the flu, and headaches and other types of pain. The herb (or its essential oil) may be applied externally to help treat acne, athlete’s foot, lower back pain, sciatica, sprains, tendinitis, neuralgia, and rheumatism. To treat circulatory disorders, some authorities recommend rubbing a few drops of lemongrass oil on the skin of affected areas; it is believed to work by improving blood flow. Like many essential oils, lemongrass is also used in aromatherapy.
The link between lemongrass and cholesterol was investigated by researchers from the Department of Nutritional Sciences, University of Wisconsin, who published their findings in the medical journal Lipids in 1989. They conducted a clinical trial involving 22 people with high cholesterol who took 140-mg capsules of lemongrass oil daily. While cholesterol levels were only slightly affected in some of the participants—cholesterol was lowered from 310 to 294 on average—other people in the study experienced a significant decrease in blood fats. The latter group, characterized as responders, experienced a 25-point drop in cholesterol after one month, and this positive trend continued over the course of the short study. After three months, cholesterol levels among the responders had decreased by a significant 38 points. Once the responders stopped taking lemongrass, their cholesterol returned to previous levels. It should be noted that this study did not involve a placebo group, which is usually used to help measure the effects of the agent being studied (in this case, lemongrass oil).
Considered an antiseptic and astringent, essential oil of lemongrass is also used by some people to cleanse oily skin and help close pores. Some herbalists recommend mixing a few drops of lemongrass with a normal portion of mild shampoo to combat greasy hair. Lemongrass essential oil can also be used as a deodorant to curb perspiration.
Last but not least, the herb has a strong reputation as an insect repellent. It is an important ingredient in several products designed to keep bugs at bay. Some authorities recommend rubbing the crushed herb directly on exposed areas of skin to avoid insect bites when enjoying the great outdoors.
The relative safety and stability of lemongrass oil has recommended it to pharmaceutical researchers who are testing new methods of quantitative analysis. Lemongrass oil has been used to demonstrate the superiority of near-infrared spectroscopy to older methods of determining the chemical content of plant oils.
The optimum daily dosage of lemongrass, which is available as fresh or dried herb or as lemongrass oil, has not been established with any certainty. Because lemongrass has been recommended for so many different purposes, and can be used internally and externally, consumers are advised to consult a doctor experienced in the use of alternative remedies to determine proper dosage. There is a significant difference between the external use of a few drops of essential oil, and the use of larger amounts of the herb in a tincture or tea.
Lemongrass tea can be prepared by steeping 1–2 tsp of the herb (fresh or dried) in a cup of boiling water. The mixture should be strained after 10–15 minutes. The tea is generally taken several times a day. In Heinerman’s Encyclopedia of Healing Herbs & Spices, John Heinerman recommends using one cup of lemongrass tea every four hours to reduce fever. In the Green Pharmacy, prominent herbalist James Duke recommends drinking one to four cups of lemongrass tea a day to benefit from its anti-fungal properties. The used tea bags can also be applied externally as fungi-fighting compresses, according to the author.
To alleviate gas or persistent vomiting, Heinerman recommends a dose of 3–6 drops of lemongrass oil (the Cymbopogon citratus variety). It may be placed on a sugar cube or mixed with 1 tsp of real vanilla flavor before swallowing. For sciatica, lower back pain, sprains, tendinitis, and rheumatism, the author suggests rubbing 10 drops of the essential oil onto the skin of the affected areas.
Lemongrass is not known to be harmful when taken in recommended dosages, though it is important to remember that the long-term effects of taking the herb (in any amount) have not been investigated. The essential oil should not be used internally by children, women who are pregnant or breast-feeding, or people with liver or kidney disease.
In rare cases, lemongrass essential oil has caused allergic reactions when applied to the skin. To minimize skin irritation, dilute the oil in a carrier oil such as safflower or sunflower seed oil before application. As with all essential oils, small amounts should be used, and only for a limited time.
Avoid getting lemongrass (herb or oil) in the eyes. Citral has been reported to irritate the respiratory tract in sensitive people as well as the eyes and skin.
When taken internally in recommended dosages, lemongrass is not associated with any bothersome or significant side effects. Cases have been reported, however, in which people have developed skin rashes after drinking lemongrass tea.
As of 2003, lemongrass is not known to interact adversely with any drug or dietary supplement.