Are There Any Dangers To Using Aloe Vera?

Aloe vera is a succulent plant that belongs to the lily family, just like the lily, onion, garlic or tulip. It grows in hot and dry climates and stores water in its leaves, which allows it to survive in these conditions. From the external part of its leaf is drawn the latex, a yellow and bitter sap. The gel, colorless and viscous in texture, is contained inside the leaves and can be collected by cutting them. Gel and latex differ in their chemical composition and are not used for the same applications. Latex is used for ingestion for its intestinal properties. In cosmetics, it is the gel that is used. It contains no less than a hundred active substances, nutrients and other components. Among these, the soothing properties of the gel are partly attributed to the polysaccharides it contains and more precisely to two compounds, acemannan and mannose-6-phosphate. Compounds such as proteins, lipids and mineral salts further enrich the cosmetic properties of the gel. Thanks to this rich chemical composition, it has various biological activities making Aloe vera a standard in natural cosmetics.

Today, most cosmetic products are made of purified Aloe vera gel so that they do not contain anthraquinones, the main allergens. Topical use of the gel has so far not revealed any notable adverse effects, it is considered non-harmful.

Older studies have reported cases of allergic dermatitis, itching and burning. These effects were very rare, mild in intensity and reversible upon discontinuation of treatment. Moreover, these cutaneous reactions were more attributed to the preservatives contained in the preparations than to the gel itself, or to the anthraquinones present in the badly purified gels. It should be noted that these studies reporting these few cases of adverse reactions are more than 20 years old, when the use of irritant extracts of the leaf was still common.

It should be noted, however, that a study carried out on mice treated with creams containing Aloe vera extract and subjected to sunlight showed little photo carcinogenic activity. Aloe-emodin would be the molecule incriminated in this phenomenon. It is therefore preferable to use dermo-cosmetic products containing the gel and not the extract because of the risk of photocarcinogenesis.

By mouth, hepatotoxicity is an undesirable effect commonly linked to the ingestion of herbal food supplements. The first case of acute hepatitis attributable to the intake of an Aloe vera compound was reported in 2005 in Germany. Subsequently, cases of Aloe-induced toxic hepatitis have been reported in Turkey, the United States, Argentina and Korea. The patients' condition improved considerably when they stopped taking the Aloe compound. Nevertheless, these confirmed cases of acute intoxication by ingestion of Aloe vera extracts remain isolated cases in the literature.

In Europe, Aloe vera in all its forms (INCI names: Aloe Barbadensis Flower Extract, Aloe Barbadensis Leaf, Aloe Barbadensis Leaf Extract, Aloe Barbadensis Leaf Juice, Aloe Barbadensis Leaf Polysaccharides, Aloe Barbadensis Leaf Water) is authorized for use in organic cosmetics according to the COSMOS standard. It is authorized for over-the-counter sale in the form of juice or gel according to Decree No. 2008-841 of August 22, 2008, on the sale to the public of medicinal plants listed in the Pharmacopoeia and amending Article D. 4211-11 of the Public Health Code. Mucilage and juice are also included in the list A of traditionally used medicinal plants in the 2012 edition of the French Pharmacopoeia. However, the origin and the extraction method are not specified. The marketing of the juice is restricted to pharmacies while the gel can be sold in any shop. Indeed, the Decree n°2008-841 authorizes the sale of mucilage as is or in powder form by persons other than pharmacists.

• SELORES M. & al. Allergic contact dermatitis to Aloe vera. Contact Dermatitis (2007).

• Photococarcinogenesis study of Aloe vera in SKH-1 mice (Simulated solar light and topical application study). National Toxicology Program Technical Report (2010).

• NAN MEI & al. Aloe vera: A review of toxicity and adverse clinical effects. Journal of Environmental Science and Health (2016).