(health/super foods/aloe vera)
Aloe vera is a species of succulent plant that probably originated in northern Africa. The species does not have any naturally occurring populations, although closely related aloes do occur in northern Africa.
The species is frequently cited as being used in herbal medicine since the beginning of the first century AD. Extracts from A. vera are widely used in the cosmetics and alternative medicine industries, being marketed as variously having rejuvenating, healing or soothing properties. There is, however, little scientific evidence of the effectiveness or safety of A. vera extracts for either cosmetic or medicinal purposes, and what positive evidence is available is frequently contradicted by other studies. Medical uses of aloe vera are being investigated as well.
Aloe vera is a stemless or very short-stemmed succulent plant growing to 60–100 cm (24–39 in) tall, spreading by offsets. The leaves are thick and fleshy, green to grey-green, with some varieties showing white flecks on the upper and lower stem surfaces. The margin of the leaf is serrated and has small white teeth. The flowers are produced in summer on a spike up to 90 cm (35 in) tall, each flower being pendulous, with a yellow tubular corolla 2–3 cm (0.8–1.2 in) long. Like other Aloe species, Aloe vera forms arbuscular mycorrhiza, a symbiosis that allows the plant better access to mineral nutrients in soil.
Scientific evidence for the cosmetic and therapeutic effectiveness of aloe vera is limited and when present is frequently contradictory. Despite this, the cosmetic and alternative medicine industries regularly make claims regarding the soothing, moisturizing, and healing properties of aloe vera, especially via Internet advertising.Aloe vera gel is used as an ingredient in commercially available lotions, yogurt, beverages, and some desserts, although at certain doses, it has toxic properties when used either for ingested or topical applications.
Research & Medical Uses
Aloe vera may be effective in treatment of wounds. Evidence on the effects of its sap on wound healing, however, is limited and contradictory. Some studies, for example, show that aloe vera promotes the rates of healing, while, in contrast, other studies show that wounds to which aloe vera gel was applied were significantly slower to heal than those treated with conventional medical preparations. A 2007 review concluded that the cumulative evidence supports the use of aloe vera for the healing of first to second degree burns. Topical application of aloe vera may also be effective for genital herpes and psoriasis. However, it is not effective for the prevention of radiation-induced injuries. Although anecdotally useful, it has not been proven to offer protection from sunburn or suntan.
In a double-blind clinical trial, both the group using an aloe vera containing dentifrice and the group using a fluoridated dentifrice had a reduction of gingivitis and plaque, but no statistically significant difference was found between the two.
There is preliminary evidence that A. vera extracts may be useful in the treatment of diabetes and elevated blood lipids in humans. These positive effects are thought to be due to the presence of compounds such as mannans, anthraquinones and lectins.Internal intake of aloe vera has been linked in preliminary research with improved blood glucose levels in diabetics, although it has been suggested by the NTP that aloe may lower blood glucose levels. It has also been linked with lower blood lipids in hyperlipidaemic patients, but also with acute hepatitis (liver disease). In other diseases, preliminary studies have suggested oral aloe vera gel may reduce symptoms and inflammation in patients with ulcerative colitis. Abdominal cramps and diarrhea have been reported with oral use of aloe vera. Diarrhea, caused by the laxative effect of oral aloe vera, can decrease the absorption of many drugs.Compounds extracted from aloe vera have been used as an immunostimulant that aids in fighting cancers in cats and dogs; however, this treatment has not been scientifically tested in humans.
Gels from Aloe vera have been compared to those derived from other aloe species and with other plants belonging to the family Asphodelaceae. Bulbine frutescens, for example, is used widely for burns and a host of skin afflictions. Aloe vera extracts might have antibacterial and antifungal activities, which possibly could help treat minor skin infections, such as boils and benign skin cysts and may inhibit growth of fungi causing tinea. For bacteria, inner-leaf gel from aloe vera was shown in one study to inhibit growth of Streptococcus and Shigella species in vitro. In contrast, aloe vera extracts failed to show antibiotic properties against Xanthomonas species.