Stevia Article Series

Stevia Side Effects -
The Facts: Part 1

Thursday, 11 January 2013

Author’s note: Having written this article I was tempted to change the title to something akin to ‘Stevia Benefits’, given the overwhelming evidence in favour of this plant.

A large amount a material is available online regarding the health implications surrounding stevia. Some is current and scientifically accurate whereas most appears misguided, outdated, incorrect and inappropriately copied from website to website with little regard to its veracity.

This article, and its successors, seeks to provide you with some of the facts, and quell some of the myths, with regards to the side effects, both positive and negative, of using steviol glycosides. It is worth mentioning, in advance that some reported adverse side effects are a result of the additives blended with pure stevia extract rather than with the extract (steviol glycoside) itself. Specific details of these additives will be covered in future articles.

Steviol glycosides are carcinogenic?

A study of toxicity data available in 2010 concluded that steviol glycosides, comprising no less that 95% stevioside and/or rebaudioside A, are not carcinogenic (producing or tending to produce cancer). No conclusion was given and no assumption should be made on possible carcinogenic properties of less pure or other forms of steviol glycoside although one would assume that less-pure samples of these steviol glycosides would be equally unlikely to produce the aforementioned adverse effects. The EFSA acknowledged the existence of further studies involving more cruder stevia extracts but concluded for various reasons that they were of little significance.
(EFSA journal 2010;8(4):1537)

A number of historical studies that investigated tumour development in animals (of existing tumours) have concluded that a number of the commonly used steviol glycosides, at varying concentrations and doses, showed no tumour-promoting effects. One such study in 2002 indicated that, administered topically, stevioside decreased skin tumour formation in female mice.
(Okamoto et al, 1983), (Konoshima and Takasaki, 2002), (Kawamori et al., 1995), (Hagiwara et al., 1984), (Ito et al., 1984), (Konoshima and Takasaki, 2002), (Yasukawa et al., 2002)

Our conclusion: Steviol glycosides are not carcinogenic

Steviol glycosides are genotoxic or associated with reproductive/developmental toxicity?

The above study, using toxicity data from in vitro and in vivo animal studies and human tolerance studies, also concluded that steviol glycosides, with composition as above, are neither genotoxic (damage genetic material) nor associated with reproductive/developmental toxicity (adverse effects on fertility, sexual function and normal growth).
(EFSA journal 2010;8(4):1537)

Our conclusion: Steviol glycosides are neither genotoxic nor harmful to growth or reproduction.