Recently, there has been information circulating online about stevia usage and its alleged effects on fertility and reproductive health. As a company committed to sharing factual, science-based information, we think it's valuable to address these misconceptions in an educational manner.
Claim: Stevia usage can cause reproductive issues in humans.
In order to address this, we must briefly discuss the origin of this claim.
The Kruc Study
In the late 1960s, Professor Joseph Kruc conducted a rat study at the University of the Republic in Montevideo, administering extremely high doses of stevia over a short period. The findings suggested reduced offspring in the stevia group compared to the control.
However, Kruc later acknowledged major limitations - the dosages were exponentially higher than typical human consumption levels, potentially causing the observed effects rather than stevia itself.
Moreover, he later admitted lack of evidence that reproductive impacts in rats would translate to humans due to physiological differences between species, limiting conclusions about stevia's effect on human fertility from this animal study alone.
The Alvarez Study
In 1988, Professor Mauro Alvarez from the University of Maringa Foundation in Brazil published a study in a Brazilian pharmaceutical journal. Alvarez reported that female mice administered stevia experienced a contraceptive effect, similar to the findings by Professor Kruc's earlier rat study.
However, critics have argued that Alvarez's study lacks crucial details, proper analysis, and the rigor required for such research, rendering it invalid and unreliable. The Herb Research Foundation has dismissed the study as entirely lacking credibility and asserted that it should be disregarded.
Remarkably, even Alvarez himself has since acknowledged that further research led him to conclude stevia is completely safe for human consumption, contradicting the implications of his own previous study.
What Does More Recent Research Say?
In short, there is no evidence to say that stevia is linked to infertility in humans:
- There are no large-scale human studies that have found a definitive link between stevia intake and adverse effects on pregnancy or birth outcomes.
- A study published in 2008 in the Journal of Endocrinology and Reproduction examined the potential effects of stevia on female fertility in mice. After administering the stevia plant extracts to the test subjects and conducting comprehensive analyses, the researchers concluded that stevia did not cause any detrimental impacts or adverse consequences related to the reproductive capabilities or fertility of the female mice (vol 12, 2008).
- A 2010 review by the European Food Safety Authority deemed steviol glycosides (the sweet compounds in stevia) as safe for use during pregnancy and lactation.
- A 2017 study published in the Journal of Toxicology evaluated the effects of high doses of steviol glycosides (the sweet compounds in stevia) on male and female fertility in rats over two generations. The researchers found no adverse effects on reproductive performance, fertility or early embryonic development even at stevia intake levels hundreds of times higher than the acceptable daily intake for humans (Curry & Roberts, 2017).
- A 2015 study in the International Journal of Impotence Research investigated stevia's effects on male reproductive health, specifically semen quality, hormone levels and sperm parameters in men. The researchers found no difference between the stevia group and the control group, concluding stevia has no adverse impacts on male fertility (Rania et al., 2015).
- Numerous other research institutions and studies have arrived at similar conclusions, affirming the lack of evidence linking stevia consumption to reproductive or fertility issues. These include investigations carried out by the Herb Research Foundation, the Medicinal Plant Research division of the United States Department of Agriculture (USDA), and the Division of Pathology under the National Institutes of Health in Japan.
While more research is always valuable, the current body of evidence clearly debunks these myths about stevia and fertility issues. As a natural, zero-calorie sweetener, stevia can be a valuable tool for those seeking to maintain a healthy lifestyle without sacrificing sweetness.