Soybeans and soy-based products are not likely to have an effect on male fertility, finds a new study published in the online journal Fertility and Sterility.
Researchers at the University of Guelph in Canada conducted a study on 32 healthy young men, testing to see if the amount of isoflavone – a component in soy that is structurally similar to estrogen – had any effect on their fertility.
"There’s been concern that maybe these estrogenic isoflavones could have adverse effects on men," explained lead author Alison Duncan.
Over three separate 57-day periods, the men were given a shake made from a milk protein in the first round, one made with low-isoflavone soy protein for the second round, and finally a high-isoflavone soy protein shake in the third round. In between each period, there was a 28-day break to clear out their systems.
"We found absolutely no effects of consuming the soy, regardless of how much isoflavones were in it, on the semen parameters, either semen volume, sperm concentration, sperm counts, sperm morphology, sperm motility. There were no changes at all," concluded Duncan.