Soya beans ‘can harm sperm’, scientists claim

Soya beans can interfere with sperm production, researchers claimed today.

Scientists in China are studying a naturally-occurring ingredient of soya beans, increasingly sold as substitutes for dairy-based food.

Their research centred on genistein, a chemical known to interact with the "receptor" molecules of cells designed to respond to oestrogens.

Ren-Shan Ge of the Wenzhou Medical College in China found that genistein could interfere with the production of enzymes involved in producing sperm.

"Following ingestion, soy isoflavones are known to reach the reproductive organs," the researchers said. "Thus, excessive exposure to agents that exhibit oestrogenic activity may affect male reproductive tract developments and functions."

But Professor Ieuan Hughes of Cambridge University said an inquiry had failed to find any adverse effects.