How much longer will we deny the growing body of research linking Roundup to infertility before calling this chemical a contraceptive?
Following closely on the heels of the EPA's decision to allow Roundup herbicide residues in your food at concentrations a million times higher than shown carcinogenic, a concerning new study published in the journal Free Radical Medicine & Biology implicates the herbicide, and its main ingredient glyphosate, in male infertility, at concentration ranges well within the EPA's "safe level" for food.
Performed by Brazilian researchers, the study found acute Roundup exposure at low doses (36ppm, 0.036g/L) for 30 minutes induced cell death in Sertoli cells in prepubertal rat testis. Sertoli cells are known as "mother" or "nurse" cells within the testicles, as they are responsible for maintaining the health of sperm cells, and are required for normal male sexual development.
Roundup herbicide exposure was found to induce oxidative stress and to activate multiple-stress response pathways within affected cells, and was associated with an increase in intracellular calcium (Ca2+) concentration leading to Ca2+ overload, and cell death.
Thirty minute incubation tests with glyphosate alone (36 ppm) also increased Ca2+ uptake, and both Roundup and glyphosate were observe to downregulate reduced glutathione levels. As glutathione is an antioxidant (electron donor) found within every cell in the human body, protecting it against oxidative stress, as well as maintaining a wide range of biochemical reactions such as DNA and protein synthesis and repair, amino acid transport, prostaglandin synthesis, amino acid and enzyme activation, a dysregulation of glutathione can result in a wide range of adverse effects.
The researchers noted "Glyphosate has been described as an endocrine disruptor affecting the male reproductive system; however, the molecular basis of its toxicity remains to be clarified. We could propose that Roundup® toxicity, implicating in Ca2+ overload, cell signaling misregulation, stress response of the endoplasmic reticulum and/or depleted antioxidant defenses could contribute to Sertoli cell disruption of spermatogenesis that could impact male fertility."
This study adds to a growing body of research implicating Roundup herbicide in male infertility:
- A 2007 study published in the journal Reproductive Toxicology found that Roundup herbicide altered the structure of the testis and epididymal region (part of the tubular spermatic duct system), as well as the serum levels of testosterone and estradiol, in male ducks, leading the researchers to conclude that Roundup "...may cause disorder in the morphophysiology of the male genital system of animals."
- A 2010 male rat study published in the Archives of Toxicology revealed prepubertal exposure to commercial formulation of the herbicide glyphosate alters testosterone levels and testicular morphology, leading researchers to describe the herbicide as "a potent endocrine disruptor."
- A 2011 male rat study published in the Archives of Toxicology revealed maternal exposure to glyphosate disturbed the masculinization process and promoted behavioral changes and histological and endocrine problems in reproductive parameters.
- A 2011 study published in the journal Toxicology In Vitro found a glyphosate-based herbicide induced necrosis and apoptosis in mature rat testicular cells in vitro, and testosterone decrease at lower levels.[i] In the study, Roundup and glyphosate at concentrations as low as 1 part per million produced a testosterone decrease in sperm cells by 35%.
- A more recent 2013 study in male rats published in the journal Ecotoxicology and Reproductive Safety found glyphosate (in combination with another pesticide) provoked severe oxidative stress in male testes, resulting in inhibited testosterone production and disrupted gonadotropin levels.