Is stevioside carcinogenic?
NO. Stevioside is not taken up by the intestines and is not metabolised by enzymes of the gastro-intestinal tract. However, it is degraded to steviol and sugar moieties by bacteria of the human colon. A weak mutagenic effect of steviol (only 90 % purity) in one sensitive Salmonella typhimurium TM 677 strain has been demonstrated but this does not mean that stevioside used as a sweetener should be carcinogenic in se, even if the stevioside is transformed to steviol by bacteria in the colon! The activity of steviol in Salmonella typhimurium TM677 was very low and was only about 1/3000 of that of 3,4-benzopyrene, and that of steviol methyl ester 8,13 lactone was 1/24500 of that of furylfuramide (Terai et al., 2002). Although a weak activity of steviol and some of its derivatives was found in the very sensitive S. typhimurium TM677 strain, the authors concluded that the daily use of stevioside as a sweetener is safe. Moreover, the presence in the blood of the chemically synthesised steviol
