A lead toxicologist from Herbalife Nutrition discusses how her team conducted a study to measure the presence of hydroxyanthracene compounds in Aloe vera.
Aloe vera is a staple in many homes for its topical uses, including addressing sunburns, dermatitis, and other skin conditions. Concurrently, Aloe vera inner leaf and decolorized whole-leaf preparations continue to be popular ingredients for the food and supplement industries, with consumers enjoying benefits from their functional components through oral consumption as well as through topical application.
Studies have shown that consumption of Aloe vera inner leaf or decolorized whole-leaf preparations may support normal blood sugar and lipid levels, promote nutrient absorption, and relieve occasional indigestion, and help maintain radiant skin and strengthen immunity. Scientific research continues to enrich our understanding of the health benefits and safety related to Aloe vera consumption.
The Presence of HADs in Aloe vera Products
Hydroxyanthracene derivatives (HADs) are a class of compounds naturally present in a variety of botanical species, including those used in food supplements to improve bowel function, usually at doses ranging from 1.2-51 mg/person/day, as reported by food business operators. HADs naturally occur in vegetables, spices, herbs, and other edible plants, including Aloe vera. The European Food Safety Authority (EFSA) published a Scientific Opinion1 in 2018 raising safety concerns over evidence of genotoxicity and carcinogenicity of HADs in food supplements used as laxatives in the EU market.
The primary HADs found in Aloe vera are aloins A and B, which derive from the inner sheath cells of the Aloe vera leaves. Aloins A and B are almost completely removed during the manufacture of Aloe vera inner leaf and decolorized whole-leaf preparations. Food and supplement Aloe vera products made with inner leaf or decolorized whole-leaf preparations with trace aloins as unavoidable impurities are not marketed for laxative purpose but for other health benefits. These Aloe vera products have a long history of safe consumption as part of a diet and numerous studies have demonstrated their safety.2
To further strengthen the safety evidence pertaining to Aloe vera products with de minimis aloins content, Herbalife Nutrition collaborated with independent scientific consultants to conduct a study3 examining dietary exposure (i.e. intakes) to known HADs from the normal diet, as well as to aloins A and B from drinkable food and supplement Aloe vera products sold on the European market which are not intended for laxative use.
Study Results: Within Intake Range
Researchers assessed exposure to known HADs from the normal diet using reported levels of occurrence of HADs in the edible parts of plants and food consumption data from the EFSA Comprehensive Database (2015) and three individual European consumptions surveys (from the UK, France, and the Netherlands). Intakes of HADs from the normal diet were estimated to range from less than 1 mcg/person/day to 600 mcg/person/day (mean) and 23 mcg/person/day to 3,599 mcg/person/day (high level). The levels of aloins A and B were also analyzed in 15 drinkable food and supplement Aloe vera products (gels, juices, or drinks) collected from six European countries.
The estimated intake of aloins A and B from these sampled Aloe vera products ranged from less than 1 mcg/person/day to 864 mcg/person/day when the product is consumed according to the direction of use indicated on the product label. The estimated intake of aloins from Aloe vera products was well within the estimated exposure of HADs in the normal diet.
The findings of this study demonstrate that dietary exposure to aloins A and B from drinkable food and supplement Aloe vera products with de minimis aloins content are within the range of intakes of HADs consumed as part of the background diet. Importantly, exposure to aloins A and B from the analyzed Aloe vera products is considerably lower than the exposure levels of HADs from food supplements used for laxative effects as reported by EFSA, of 1.2 mg/person/day to 51 mg/person/day.
Sharing HADs and Aloe vera Research with the Industry
This data was presented at the Society of Toxicology (SOT) Annual Meeting in Baltimore, MD, in March 2019, and allowed us to validate that consumption of Aloe vera products that contain very low levels of HADs and are not sold for laxative uses do not contribute significantly to the dietary exposure to HAD compounds in the normal diet.
The findings of this study provide a critical piece of evidence in the risk assessment of HADs in the human diet. This work is part of Herbalife Nutrition’s ongoing Aloe Research Program, which has led to three recent peer-reviewed publications on the analysis and characterization of chemical composition of Aloe vera in the Journal of AOAC International4. Herbalife Nutrition is committed to being a leader in aloe research and advancing the science of Aloe vera.
Jiang Hu, PhD, DABT, is the senior principal scientist of global product science and safety at Herbalife Nutrition.