Researchers at the University of California at Davis Medical Center set out to test the effect of two aloe vera preparations and placebo in a human clinical trial, citing the motivation that vitamin B12 is deficient in vegetarians and the aging population. The UC Davis study demonstrated the potential for aloe to enhance the bioavailability of vitamins C and B12, as well as ORAC. The favorable results of this study, which is awaiting peer-reviewed publication, back-up a previous study showing aloe enhances the absorption of vitamin C and E, thereby potentially opening up a new category for the use of aloe in dietary supplements. "Bioavailability is a very important topic in the dietary supplement industry at this time," Ken Jones, chief science officer and president of the International Aloe Science Council (IASC), told NutraIngredients-USA. "So this elevates aloe and expands its uses." The IASC and the Aloe Institute funded both studies, in which the company Aloecorp played no role, said Jones. Aloe vera, from the tree lily family aloe barbadensis, has traditionally been used as an all-purpose herbal plant. The aloe whole leaf extract or aloe fillet gel can be used as functional ingredients in the form of a juice or powder. In dietary supplements, ingredients derived from the botanical have been used for immune support and relieving oxidative stress. The UC Davis randomized cross-over trial involved 15 participants between 40 and 80 years of age who were given their vitamins with either aloe whole leaf extract, aloe fillet gel, or just water. The vitamins consisted of 1mg of vitamin B12 and 500mg of vitamin C. Blood was then obtained from the subjects following one, two, four, six, eight and 24-hour post-ingestion of the aloe or water combinations, with one week between treatments. Researchers indicated that neither the aloe whole leaf extract nor the aloe fillet gel affected lipid or glucose levels. The aloe gel significantly increased plasma ORAC (Oxygen Radical Absorbance Capacity) at both four and 24 hours while the aloe leaf extract significantly increased it at four hours compared to baseline and placebo (AUC, 24h, p<0.05). The aloe gel was also said to have increased plasma vitamin C levels four, six, eight and 24 hours following ingestion, while aloe leaf extract raised the serum vitamin C levels at four and six hours (AUC, eight and 24 hours, p<0.02). According to the researchers, vitamin B12 was also increased in the serum by both forms of the aloe ingredient at one and two hours. This could have implications for supplementation and the targeting of chronic diseases, especially in the elderly, said Jones. "One area of research - if you were going to go for that - is to look at specific conditions which could benefit from increased absorption," said Jones. The aloe specialist cited the example of gastrointestinal conditions that make it even more difficult for people to absorb vitamin B12. B12 is crucial to brain functioning, as well as for the formation of blood. The advantage of this most recent study, which is set to be published in the FASEB Journal (published by the Federation of American Societies for Experimental Biology), according to Jones, is that it has set a dosing parameter for the use of aloe vera and bioavailability. "Now we have specific doses associated with a specific action," said Jones. Aloe has established applications for cosmetics and dietary supplements, as well as in the growing crossover category for these two markets: cosmeceuticals. The application for bioavailability would create a new category for uses in dietary supplements. The previous aloe vera bioavailability study, published in 2005 in the Phytomedicine journal, involved healthy subjects ranging between the ages of 21 and 42. Aloe was found to improve both the absorption of vitamins C and E. It now remains for supplement makers to in turn test aloe ingredients in their products. Like any other plant-derived ingredients, aloe has its own shelf-life and stability challenges which would have to be assessed, said Jones. Source: Vinson, J.A., H. Al Kharrat and L. Andreoli. "Effect of aloe vera preparations on the human bioavailability of vitamins C and E." Phytomedicine. 12 (2005) 760-765.