In addition to Aloe barbadensis, however, other Aloe species are used for many different purposes. Inter alia, the sap of the pressed, whole, unpeeled leaves of Aloe arborescens (krantz aloe, candelabra aloe) is marketed in the form of food supplements. The German Federal Institute for Risk Assessment (BfR) has assessed the possible health risks of such food supplements. The outer layers of the leaves of Aloe arborescens are of toxicological relevance. As with all Aloe species, these layers contain plant-based anthranoids which have long been suspected of having a genotoxic and carcinogenic effect. In addition to data on the pure substances, tests have also been conducted in the meantime on anthranoid-containing preparations made from Aloe leaves. The results of these long-term studies also confirm the suspicion of carcinogenicity, but there are data gaps which should be closed with regard to the details and mechanisms of cancer development.
The BfR comes to the following conclusion on the basis of the available data: according to the latest guidelines issued by the European Food Safety Authority (EFSA) for the assessment of botanical preparations, products which contain preparations of the unpeeled leaves of Aloe arborescens, and thereby anthranoids, do not belong to the category of botanical food supplements which can be designated as being of "no safety concern" based on current knowledge. Due to the suspicion that plant-based anthranoids have a carcinogenic effect in humans, the BfR does not consider preparations containing anthranoids to be suitable for use in foods, including food supplements. This assessment does not apply to preparations made from anthranoid-free gel or inner pulp from the leaves of Aloe species (mostly Aloe barbadensis or Aloe vera), which are commonly used in foods and cosmetics in the EU. Anthranoids should generally not be present in foods in the view of the BfR. When producing foods with leaves of plants of the Aloe genus, the anthranoid-containing outer leaf layers should be carefully removed in order to keep contamination with anthranoids, which are suspected carcinogens, as low as possible.
The full version of this BfR opinion is available in German on: http://www.bfr.bund.de/cm/343/nahrungsergaenzungsmittel-mit-anthranoidhaltigen-aloeganzblattzubereitungen-bergen-gesundheitliche-risiken.pdf
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