What is Aloe Vera? (Also known as Aloe barbadensis)
Aloe vera is a succulent plant1 belonging to the Liliaceal family, of which there are more than 360 species2. Aloe vera is a common name for Aloe barbadensis, the most widely used species of aloe3. It is often used in ointments, creams, and lotions intended for wound healing or skin protection. The International Aloe Science Council (IASC) describes three components of the plant that are used: leaf juice (whole leaf as the starting point), innerleaf juice (from the inner gel fillet), and aloe latex (yellow-brown sap between the inner parenchymous tissues)4.
Where Does Aloe Vera Come From?
Many authors have considered Aloe to be a member of the Liliaceae family, but it comes from a family of its own called Aloaceae5. This plant is however related to the Liliaceae family, and therefore also related to plants such as onion, garlic, and asparagus, which are known to have medicinal properties6. Most of these plants originated in the dry regions of Africa, Asia, and Southern Europe, especially in the Mediterranean regions7.
Aloe Vera Benefits
Good scientific evidence exists for beneficial effects of topical aloe vera in genital herpes, psoriasis vulgaris, and seborrheic dermatitis8. Monographs from Health Canada, the German Commission E, and the World Health Organization recognise the use of oral aloe vera as a laxative8-10; however, limited or conflicting evidence exists for other usesm including diabetes mellitus, dyslipidemia, sore throat, hypertension, osteoarthritis, inflammatory bowel disease, fever, itching, asthma, epilepsy, depression, glaucoma, multiple sclerosis, and vision problems11.
Negative Side Effects of Aloe Vera
Some studies have suggested that Aloe vera in skincare preparations may enhance the induction of skin cancer by ultraviolet radiation. A 1-year study was conducted in mice to determine whether the topical application of creams containing Aloe vera plant extracts (aloe gel, whole leaf, or decolorized whole leaf) or creams containing aloe-emodin would enhance the photocarcinogenicity of simulated solar light. The study found only a weak enhancing effect of aloe gel or aloe-emodin on the photocarcinogenic activity of simulated solar light in female but not in male mice12. In terms of its oral use, aloe is not carcinogenic at nontoxic-dose levels but when incorporated into the diet of rats at a level of 4% it showed a weak carcinogenic potential on the colon probably due to irritation of the intestinal tract by diarrhea13.
Aloe Vera Recommended Dosages & Timing
Given the main indication for aloe vera is as a topical agent, there are no specific dosage recommendations. Topical aloe vera is commonly used for sunburn damage to skin and therefore is applied soon after exposure to sun.
Aloe Vera Supplements
Aloe vera is most commonly sold in topical form, either as a gel or cream. It can also be sold in the form of powder or capsule for oral consumption.
Stacking Aloe Vera
Aloe vera is not commonly stacked with other nutrients, except in the case of topical applications where it may be combined with other extracts with purported benefits for skin, such as calendula, green tea, chamomile, grape seed, oatmeal etc.
Aloe Vera Safety
Aloe vera is considered a very safe topical and oral agent when used in accordance with manufacturer’s instructions.1. Natural Medicines Comprehensive Database. Aloe monograph. www.naturaldatabase.com/(S(qvu2t455cblgtk450bop1yev))/home.aspx?cs=&s=ND (accessed 2009 Oct 13).
2. Vogler BK, Ernst E. Aloe vera: a systematic review of its clinical effectiveness. Br J Gen Pract. 1999; 49:823-8.
3.Tanaka M, Misawa E, Ito Y et al. Identification of five phytosterols from Aloe vera gel as anti-diabetic compounds. Biol Pharm Bull. 2006; 29:1418-22.
4. Natural Products Insider. International Aloe Science Council presents a scientific primer on aloe. www.naturalproductsinsider.com/ebooks/2009/10/iascpresents-a-scientific-primer-on-aloe.aspx (accessed 2010 Feb 18).
5. Reynolds T. The compounds of Aloe leaf exudates: a review. Bot J Linn Soc.1985;90:157–177.
6. Lawless J, & Allan J. (2000). Aloe vera – Natural wonder cure. Harper Collins Publihers, Hammersmith, London.
7. Urch, D. (1999). Aloe vera – Nature’s gift. pp. 7–13. Blackdown Publications, Bristol, England.
8. Ulbricht C, Armstrong J, Basch E et al. An evidence-based systematic review of aloe vera by the Natural Standard Research Collaboration. J Herb Pharmacother. 2007; 7(3):279-323.
9. German Commission E. Aloe (Aloe barbadensis Aloe capensis). List of German Commission E monographs (phytotherapy). www.heilpflanzen-welt.de/buecher/ BGA-Commission-E-Monographs/0002.htm (accessed 2009 Oct 13).
10. Health Canada. Drugs and health products: aloe vera. www.hc-sc.gc.ca/ dhp-mps/prodnatur/applications/licenprod/ monograph/mono_aloe-eng.php (accessed 2009 Oct 13).
11. Ngo MQ, et al. Oral aloe vera for treatment of diabetes mellitus and dyslipidemia. Am J Health-Syst Pharm.2010;67(1):1804-1811.National Toxicology Program. Photocarcinogenesis study of aloe vera [CAS NO. 481-72-1(Aloe-emodin)] in SKH-1 mice (simulated solar light and topical application study).
12. National Toxicology Program Technical Report Series. (553):7-33, 35-97, 99-103 passim, 2010 Sep.
13. Yokohira M. et al. Equivocal colonic carcinogenicity of Aloe arborescens Miller var. natalensis berger at high-dose level in a Wistar Hannover rat 2-y study. Journal of Food Science. 2009;74(2):T24-30.