ALOE VERA: AN UPDATE FOR EUROPE?

Aloe vera use can be traced back to Ancient Egypt. Its various properties mean it has been widely used in cosmetics, foodstuffs, and in the health industry. In recent years, consumers have developed habits concerning its regular digestion and use because it is deemed to be healthy and natural. However, concerns are now growing over possible side effects from long-term use, including links to cancer. The jury is now out; what does this mean for Europe’s aloe vera industry?

• Aloe vera is a succulent plant species originating from the Arabian Peninsula. Its wide variety of uses in cosmetics, food and healthy products mean its market has grown significantly in recent years and that trend is set to continue. By 2025, the global market for aloe vera is predicted to reach USD 2.67 billion, a reflection of the trust consumers have in its product¹.
• In 2013, however, the European Food Safety Authority (EFSA) issued a warning concerning hydroxyanthracene derivatives (HADs) – active substances found in aloe vera plants, along with rheum, rhamnus and senna. It found that, “hydroxyanthracene derivatives in food can improve bowel function but advised against long-term use and consumption at high doses due to potential safety concerns.”²
•  

Uses for Aloe Vera

The plant produces two substances that can be used in consumer products – a clear gel and a yellow latex. Their benefits have been recognized by the cosmetics, food and health industries for a long time. The clear gel that can be consumed as a foodstuff or used as a topical medications for skin conditions, and the yellow latex is orally ingested as a treatment for constipation.

Uses of aloe vera include:

1. Cosmetics: gel is used in liquids, creams, sun lotions, shaving creams, lip balms, healing ointments, face packs, aftershave gel, mouthwash, hair tonics, shampoo and skin moistening gels
2. Foods: extracts are used as a bitter flavoring in beverages, in health and soft drinks, yoghurt, jams, instant tea granules, candies, ice cream and supplements
3. Medicines: gel and latex are reported to possess a wide range of pharmaceutical properties - anthrachinone glycosides found in aloe vera have laxative properties
4.  

Aloe Vera as a Raw Material

The various parts of an aloe vera part have different qualities. These include:

1. Whole leaf gel – made from the whole leaf including rind, latex layer and inner gel (without stripping the rind)
2. Inner leaf gel – made by peeling leaves. The bark and latex layer are then cut off and wasted, with only the parenchymatous tissue being processed and used
3. Decolorized whole leaf – the ‘whole leaf’ is processed by filtration with activated charcoal, thereby clearing the liquid aloe mass
4. Aloe latex – a brown, yellow-brown or occasionally red exudate found between the rind and the inner leaf. Sometimes called ‘sap’, it contains several constituents, most notably anthrachinones
5. Aloe vera gel extract - inner leaf pulp contains the large gel-producing cells. The mechanical extrusion of the mucilaginous gel from the inner leaf pulp gives a 70% yield with a water content of 99-99.5% 
6. Aloe vera whole leaf extract – (syn. whole leaf aloe vera juice, aloe juice or non-decolorized whole leaf extract). An aqueous extract of the whole leaf with lignified fibers removed, containing both the gel from inner parenchyma leaf pulp and the latex.
7. Aloe decolorized whole leaf extract – (syn: decolorized whole leaf extract). Activated carbon is used on aloe vera whole leaf extract to remove the bitterness and color caused by the anthrachinone composition of the latex
8. Dried aloe vera latex – a solidified liquid originating in the cells of the pericycle and leaf parenchyma and flowing spontaneously from the cut leaf. It is dried with or without the aid of heat and is used for medical purposes. Its composition is specified in several official pharmacopeias

Inner leaf gel is the plant part most widely used in the food industry.
HADs are primarily found in the outer layer of the leaves, in the latex found between the green shell and inner leaf. The EFSA has initiated evaluating these substances for safety³. 

Global Market for Aloe Vera

Despite the predicted growth in the global aloe vera market, the EFSA investigations and the Prop 65 listing may negatively impact the market. Other factors influencing international trade in the raw material include:

1. Species - Africa mainly relies on aloe arborescence, which has a naturally high level of aloin and other HADs. In Mexico, the USA and EU, the dominant form is aloe barbadensis Miller L.
2. Manufacturing process – (whole leaf extract WLE and inner leaf extract ILE), type of extraction, etc.

While there is considerable trust in aloe vera among consumers, the opinion of the EFSA is bound to have a significant impact on European and global markets for aloe vera. The current discussion concerning the safety of HADs is being closely watched by both manufacturers and associations, such as Food Supplements Europe (FSE).  

Is Aloe Vera Safe?

Ultimately, for governments, the industry and consumers, the question that needs to be answered is, is aloe vera safe or not?

The following respected authorities currently recognize aloe vera as a food and/or food supplement:

1. Codex Alimentarius – food category, 42nd session, chapter 4.1.1. fresh fruit, Annex to Table 3⁴
2. BVL List of Substances of the Competent Federal Government and Federal State Authorities – aloe barbadensis Mill. gel listed for food use and leaf juice as a medical substance
3. BELFRIT list (harmonized list created by Belgium, France & Italy) – 1,000+ botanicals listed. Includes aloe barbadensis Mill. as a food supplement⁵  
4. THIE inventory – (list of herbals considered as foods) leaf gel included⁶

However, before and after the publication of the 2013 EFSA opinion, various Member States raised concerns over the authorization of HADs-based products in food and the European Commission asked the EFSA to initiate further investigations.

A summary of current opinions regards HADs includes:

1. EFSA 2013 – a cause/effect relations between HADs and improvements to bowel function have been established. A minimum dosage of 10 mg of HADs is required to be effective. The Panel also highlighted that the use of laxative products should not be prolonged for more than one or two weeks (in accordance with WHO monographs, 1999). The long-term use of laxatives requires medical supervision and that their use is recommended only when the standard bowel functions cannot be re-established by a change in the diet
2. IARC 2013 Monograph – International Agency for Research on Cancer (IARC) included aloe vera in a discussion of drug and herbal products. Whole leaf extract showed evidence of carcinogenicity during animal testing; therefore, it has been classified as possibly carcinogenic to humans and included in ‘Group 2B’
3. EMA (2007 – 2017) – European Medicines Agency (EMA) has published various monographs on HADs, including aloe species. Occasional and short-term use of HADs by the adult population is considered safe but use by children under 12 and adults during lactation and pregnancy is not. The question over the carcinogenic potential of these substances is left open
4. BfR 2017 – German Federal Institute for Risk Assessment (BfR) published an opinion on food supplements, based on whole-leaf-aloe preparations. The toxicological evaluation was directed towards preparations containing anthranoids, found in the outer layer of all aloe species. The focus of the study was on aloe arborescens, commonly used as the base for food and cosmetic preparations. It found that, based on the available knowledge, products based on whole leaf preparations cannot be considered as safe because of then suspected carcinogenic properties of the anthranoids content. It also recommended the anthranoid-containing outer layers of the leaves should be removed in a way to prevent contamination when producing food
5. EFSA 2018 – Panel on Food Additives and Nutrient Sources (ANS) added to food finalized its scientific opinion on the safety of HADs in relation to consumption. The European Commission specifically asked it report on the link between HADs exposure and colorectal cancer (CRC) and provide advice on a safe daily intake for the population, including vulnerable groups. The Panel analyzed epidemiological studies that suggested there was an increase of CRC linked to the use of general laxatives

In vitro studies showed some genotoxic evidence, likely due to the presence of HADs. However, the same genotoxic evidence was seen even when the HADs had been removed from the aloe vera samples. This would suggest other components have similar effects and therefore a safe daily intake could not be set

Stakeholders operating in the European market should be aware that upcoming regulations should address safety concerns regarding individual chemical components, extracts, and extract type (pulp vs whole leaf). It should detail what can be considered safe, as well as addressing the questions that remain open regarding general safety. 

Manufacturers and consumers might consider coffee cherry tea as an alternative. The herbal tea made from the dried skin of the coffee fruit is already being used as an ingredient in some beverages as it has similar laxative benefits to aloe vera. Coffee fruit is classified as a novel food by the EFSA⁷.

¹ https://www.grandviewresearch.com/press-release/global-aloe-vera-extracts-market

² https://www.efsa.europa.eu/en/press/news/180123

3 https://www.efsa.europa.eu/en/efsajournal/pub/5090

⁴ http://www.fao.org/gsfaonline/foods/details.html?id=73&print=true

⁵ https://www.academia.edu/33744059/2016_GROUP_Botanical_Journal_of_the_Linnean_Society.pdf

⁶ https://www.thie-online.eu/fileadmin/inhalte/Publications/HFI/2016/2016-06-24_PU_THIE_Inventory_List_of_Herbals_Considered_as_Food_final.pdf

⁷ https://ec.europa.eu/food/safety/novel_food/catalogue/search/public/?event=home&seqfce=882&ascii=C