>The study cited is from 1968.
According to the results of one earlier study, Stevia extract reduced the fertility of rats by up to 21 % compared with control group of rats. Fertility remained reduced by 47 % even after a 50-60 day recovery period (Mazzei-Planas and Kuc, 1968[57]).
In Stevia-treated rats, a decrease in the relative weight of seminal vesicle and testis was observed as well as a significant decrease in the number of spermatozoa stored (Melis, 1999[60]).
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8600158/
Steviol, the active principle of the stevia sweetener, causes a reduction of the cells of the immunological system even consumed in low concentrations
Although Steviol is used globally as a sweetener, its use should be cautious, as our study points out that Steviol has cytotoxic, genotoxic and mutagenic effects in the concentrations and conditions tested in the culture of human lymphocyte cells.
Sep. 2020
https://pubmed.ncbi.nlm.nih.gov/32811239/