In a Reuters report, Lynn Fraser, a researcher with King's College London has observed genistein affects sperm in mice. But, it seems to have an even stronger effect on human sperm.
Fraser found in laboratory experiments that small amounts of the chemical could make human sperm to "burn out" and lose fertility. She says, "Human sperm proved to be even more responsive that mouse sperm to genistein."
Researchers think if women consume soya and other foods high in genistein it might have a bigger influence on male fertility because the chemical is expected to affect sperm when it is in the female preparing to fertilize an egg.
Fraser adds, "Maternal exposure to the compounds is probably more important than paternal exposure."
