Aloe vera, sometimes described as a "wonder plant", is a short-stemmed shrub that only occurs in cultivation - it cannot be found in the wild. Some related Aloes occur naturally in North Africa. An Aloe is a genus containing more than 500 species of flowering succulent plants.
The Aloe vera leaves are succulent, erect and form a dense rosette. Many uses are made from the gel obtained from the plant's leaves
Aloe vera has been the subject of scientific study for the last few years, along with other members of the Aloe genus regarding several claimed therapeutic properties.
According to Kew Gardens, England's royal botanical center of excellence, Aloe vera has been used for centuries and is currently more popular than ever. It is cultivated worldwide, primarily as a crop for "Aloe gel", which comes from the leaf.
Aloe vera is widely used today in:
- food - it is approved by the FDA (U.S. Food and Drug Administration) as a natural flavoring
- cosmetics
- food supplements
- herbal remedies
The earliest records of Aloe vera being used by humans appear in the Ebers Papyrus (Egypcian medical papyrus) from 16th century BC. According to a study published in the Indian Journal of Dematology, in ancient Egypt they called Aloe vera "that plant of immortality". The authors added that the plant has been used therapeutically for many centuries in China, Japan, India, Greece, Egypt, Mexico and Japan.
Cleopatra and Nefertiti, two queens of Egypt, apparently used Aloe vera to keep their skin soft. It was used to treat soldiers' wounds by Christopher Columbus and Alexander the Great.
Pedanius Dioscorides (circa 40-90 AD) a Greek physician, pharmacologist and botanist, mentioned Aloe vera and its therapeutic qualities in "De Mataria Medica", a 5-volume encyclopedia about medical substances and herbal medicine - it was widely read for over 1,500 years.
Gaius Plinius Secundus (AD 23-79), better known as Pliny the Elder, a Roman author, naturalist, and natural philosopher, mentioned Aloe vera's therapeutic benefits in "Natural History", an early encyclopedia - one of the major single works to have survived from the Roman Empire.
What are the therapeutic benefits of Aloe vera?
The medicinal claims made about Aloe vera, as with many herbs and plants, are endless. Some are backed by rigorous scientific studies while others are not. This article attempts to focus mainly on those that have been backed up by science.
Teeth and gums
A study published in General Dentistry reported that Aloe vera in tooth gels is as effective as toothpaste in fighting cavities.
The researchers compared the germ-fighting ability of an Aloe vera tooth gel with two popular toothpastes and found that the gel was just as effective, and in some cases even better than the commercial brand toothpastes at controlling cavity-causing oral bacteria.
The authors explained that Aloe latex contains anthraquinones, compounds that are used in healing and reducing pain because of their natural anti-inflammatory effects.
Aloe vera gel
As Aloe vera gel is less harsh on the teeth than commercial toothpaste because it does not contain abrasive elements, people with sensitive teeth and gums may benefit, the researchers wrote.
The scientists warned that not all gels they analyzed contained the proper form of Aloe vera - they must contain the stabilized gel that exists in the center of the plant in order to be effective.
Study co-author, Dilip George, MDS, said "(the gel) must not be treated with excessive heat or filtered during the manufacturing process, as this destroys or reduces the effects of certain essential compounds, such as enzymes and polysaccharides." Dr. George recommends checking with non-profit associations, such as the International Aloe Science Council to determine which products have received its seal of quality.
Constipation
Germany's regulatory agency for herbs - Commission E - approved the use of Aloe vera for the treatment of constipation. Dosages of between 50 to 200 milligrams of Aloe latex are commonly taken in liquid or capsule form once daily for up to ten days.
The US Food and Drug Administration (FDA) ruled in 2002 that as there is not enough data on the safety and efficacy of Aloe products; in the USA they cannot be sold to treat constipation.
Diabetes-induced foot ulcers
According to a study carried out at the Sinhgad College of Pharmacy, India, and published in the International Wound Journal a "gel formed with carbopol 974p (1%) and Aloe vera promotes significant wound healing and closure in diabetic rats compared with the commercial product and provides a promising product to be used in diabetes-induced foot ulcers".
Antioxidants and possibly antimicrobial properties
Researchers at the University of Las Palmas de Gran Canaria, Spain, wrote about a study in the journal Molecules.
The team had set out to determine whether the methanol extract of leaf skins and flowers of Aloe vera might have beneficial effects on human health. The scientists focused on the extract's possible antioxidant and antimycoplasmic activities. Mycoplasma are a type of bacteria that lack a cell wall, they are unaffected by many common antibiotics. Antimycoplasmic substances destroy these bacteria.
They reported that both Aloe vera flower and leaf extracts had antioxidant properties, especially the leaf skin extract. The leaf skin extract also exhibited antimycoplasmic properties.
The authors concluded "A. Vera extracts from leaf skin and flowers can be considered as good natural antioxidant sources."
Protection from ultraviolet (UV) irradiation
Scientists at Kyung Hee University Global Campus, South Korea, wanted to determine whether baby aloe shoot extract and adult aloe shoot extract might have a protective effect on UVB-induced skin photoaging, i.e. whether they might protect the skin from the aging effect when exposed to sunlight.
Baby aloe shoot extract (BAE) comes from 1-month old shoots while adult aloe shoot extract (AE) comes from 4-month old shoots.
The team explained that UV irradiation induces photo-damage of the skin and can permanently change skin structure.
In an article published in Phytotherapy Research, the authors concluded "Our results suggest that BAE may potentially protect the skin from UVB-induced damage more than AE."
Protection from skin damage after radiation therapy
A study carried out at the University of Naples, Italy, tested five different topical creams to see how effective they might be in protecting the skin of breast cancer patients receiving radiation therapy.
They tested the following hydrating creams - Vitis vinifera A. s-I-M.t-O.dij (Ixoderm®), Alga Atlantica plus Ethylbisiminomethylguaicolo and Manganese Cloruro (Radioskin1®) and Metal Esculetina plus Ginko Biloba and Aloe vera (Radioskin 2®); Natural triglycerides-fitosterols (Xderit®); Selectiose plus thermal water of Avene (Trixera+®); and Betaglucan, sodium hyaluronate (Neoviderm®).
They divided 100 patients into five groups of 20, each one was prescribed a different topical treatment. They applied the creams twice daily, starting 15 days before radiation therapy treatment, and carried on for one month afterwards.
During the whole 6-week period, the participants underwent weekly skin assessments.
In the journal Radiation Oncology, the scientists reported that the preventive use of the topical hydrating creams reduced the incidence of skin side effects in the women treated with radiation therapy for breast cancer. "All moisturizing creams used in this study were equally valid in the treatment of skin damage induced by radiotherapy."
Depression, learning and memory - an animal experiment
A study published in Nutritional Neuroscience found that Aloe vera reduces depression and improves memory in mice. The researchers explained as background information that the plant had been used since ancient times for the treatment of infection, constipation and skin disorders.
The authors wanted to determine what effect Aloe vera might have in learning, memory, depression and locomotion.
After carrying out some experiments on laboratory mice, the scientists concluded "Aloe vera enhances learning and memory, and also alleviates depression in mice." Further studies are needed to find out whether humans might also receive the same benefits.
Wounds from second degree burns
A team of plastic surgeons compared Aloe vera gel to 1% silver sulphadiazine cream for the treatment of second degree burn wounds.
They reported in the Journal of Pakistan Medical Association that the burn wounds among the patients treated with Aloe vera healed remarkably earlier compared to those treated with with 1% silver sulfadiazine (SSD).
The researchers added that those in the Aloe Vera group experienced significantly more and earlier pain relief than those in the SSD group.
In an Abstract in the same journal, the authors wrote "Thermal burns patients dressed with Aloe vera gel showed advantage compared to those dressed with SSD regarding early wound epithelialization, earlier pain relief and cost-effectiveness."
Irritable bowel syndrome - inconclusive
A randomized, double-blind human trial carried out at St Georges Hospital Medical School, London, UK, did not find a significant difference in symptoms of diarrhea after 3 months when patients on Aloe vera were compared to those on placebo.
However, the researchers wrote in the International Journal of Clinical Practice"There was no evidence that AV (aloe vera) benefits patients with IBS. However, we could not rule out the possibility that improvement occurred in patients with diarrhoea or alternating IBS whilst taking AV. Further investigations are warranted in patients with diarrhoea predominant IBS, in a less complex group of patients."
Many claims lack scientific studies
Most health authorities in North America, Europe, Australasia and Japan say that many of the dozens of therapeutic benefits associated with Aloe vera need to be studied scientifically. This does not mean the claims are necessarily inaccurate.
According to the National Center for Complementary and Alternative Medicine (NCCAM) in the United States, part of the National Institutes of Health, Aloe latex contains strong laxative compounds. Products containing aloin, aloe-emodin, and barbaloin (components of Aloe) were once regulated by the FDA as oral OTC laxatives. In 2002, the FDA required that all OTC Aloe laxatives be removed from the market or reformulated because of a lack of safety data. Studies have shown that topical Aloe gel may help in abrasions and burns..... The NCCAM wrote "There is not enough scientific evidence to support Aloe vera for any of its other uses."