Herbs & Supplements:
Aloe
Aloe vera
Principal Proposed Uses
•
Topical Uses, Wound Healing, Burn Healing, Genital Herpes, Psoriasis, Seborrhea, Oral Uses, Diabetes
Other Proposed Uses
•
Oral Uses, AIDS, Asthma, Ulcers, Immune Weakness
The succulent aloe plant has been valued since prehistoric times for the treatment of burns, wound infections, and other skin problems. Medicinal aloe is pictured in an ancient cave painting in South Africa, and Alexander the Great is said to have captured an island off Somalia for the sole purpose of possessing the luxurious crop of aloe found there.
Most uses of aloe refer to the gel inside its cactus-like leaves. However, the skin of the leaves themselves can be condensed to form a sticky substance known as "drug aloe" or "aloes." It is a powerful laxative, and an unpleasant one. The uses described below refer only to aloe gel.
What Is Aloe Used for Today?
We suspect millions of people would swear by their own experience that applying aloe to the skin can drastically reduce the time it takes for burns (including sunburn) to heal. However, aloe appears to be ineffective for treating sunburn and may actually be detrimental for second degree burns.1,2
Studies in animals suggest that topical aloe gel may improve wound healing.3,4,5 However, one report suggests that aloe can actually impair the healing of severe wounds.6 Aloe has also failed to prove effective for protecting the skin during radiation therapy.7
There is actually better evidence (although still imperfect) for three lesser-known uses of topical aloe: genital herpes, psoriasis, and seborrhea.
Intriguing evidence suggests that aloe gel taken orally might be helpful for type 2 diabetes.8,9
Oral Aloe vera is also sometimes recommended to treat AIDS, asthma, stomach ulcers, and general immune weakness. While the evidence for benefit in these conditions is slight to nonexistent, one of the constituents of aloe, acemannan, does seem to possess numerous interesting effects. Test tube and animal studies suggest that it may stimulate immunity and inhibit the growth of viruses.10,11,12 However, it remains to be discovered whether this preliminary research will translate into actual benefits in human beings. Aloe vera is definitely not a proven treatment for any of these conditions.
What Is the Scientific Evidence for Aloe?
Genital Herpes
A 2-week double-blind placebo-controlled trial enrolled 60 men with active genital herpes.13 Participants applied aloe cream (0.5% aloe) or placebo cream 3 times daily for 5 days. Use of aloe cream reduced the time necessary for lesions to heal (4.9 days versus 12 days), and also increased the percentage of individuals who were fully healed by the end of 2 weeks (66.7% versus 6.7%).
A previous double-blind placebo-controlled study by the same author enrolling 120 men with genital herpes found that aloe cream was more effective than pure aloe gel or placebo.14
Psoriasis
According to a double-blind study that enrolled 60 men and women with mild to moderate symptoms of psoriasis, Aloe vera cream may be helpful for this chronic skin condition.15 Participants were treated with either topical Aloe vera extract (0.5%) or a placebo cream, applied 3 times daily for 4 weeks. Aloe treatment produced significantly better results than placebo, and these results were said to endure for almost a year after treatment was stopped. The study authors also reported a high level of complete "cure," but what exactly they meant by this was not reported clearly.
Seborrhea
Seborrhea is a fairly common skin condition, leading to oily, red, and scaly eruptions in such areas as the eyebrows, eyelids, nose, ear, upper lip, chest, groin, and chin. A double-blind placebo-controlled study of 44 individuals found that 4 to 6 weeks of treatment with aloe ointment could significantly reduce symptoms of seborrhea.16
Diabetes
Evidence from two human trials suggests that aloe gel can improve blood sugar control in individuals with type 2 diabetes.
A single-blind placebo-controlled trial evaluated the potential benefits of aloe in either 72 or 40 individuals with diabetes (the study report appears to contradict itself).17 The results showed significantly greater improvements in blood sugar levels among those given aloe over the 2-week treatment period.
Another single-blind placebo-controlled trial evaluated the benefits of aloe in individuals who had failed to respond to the oral diabetes drug glibenclamide.18 Of the 36 individuals who completed the study, those taking glibenclamide and aloe showed definite improvements in blood sugar levels over 42 days as compared to those taking glibenclamide and placebo.
Although these are promising results, large studies that are double- rather than single-blind will be needed to establish aloe as an effective treatment for hypoglycemia.
Dosage
Topical aloe vera cream typically contains 0.5% aloe, and is applied 3 times daily.
For the treatment of diabetes, a dosage of 1 tablespoon of Aloe vera juice twice daily has been used in studies.
For internal use in treating AIDS and other conditions, some authorities recommend a dose of aloe standardized to provide 800 to 1,600 mg of the substance acemannan daily.
Safety Issues
Other than occasional allergic reactions, no serious problems have been reported with aloe gel, whether used internally or externally. However, comprehensive safety studies are lacking. Safety in young children, pregnant or nursing women, or those with severe liver or kidney disease has not been established.
In addition, keep in mind that if aloe is successful as a treatment for diabetes, blood sugar levels could fall too low, necessitating a reduction in medication dosage.
Interactions You Should Know About
If you are using:
- Hydrocortisone cream: Aloe gel might help it work better.19
- Medications for diabetes: Oral use of aloe vera might cause your blood sugar levels to fall too low.
View References
Last reviewed March 2002 by Medical Review Board
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