Soy may water down little swimmers: sperm research

CBC NEWS

Men who consume soy daily and want to start a family may want to reconsider
their dietary choices in light of new research.

A study published in the July 24 issue of Human Reproduction finds that men
who eat half a serving of soy per day — such as 115 g of tofu or 240 ml of soy
milk — had lower concentrations of sperm than men who didn't eat soy.

Researchers at the Harvard School of Public Health found that men who
consumed the most soy (half a serving per day) had 41 million sperm per
millilitre less than men who did not eat soy at all.

They found that there was an "inverse association between soy food
intake and sperm concentration that remained significant after accounting for
age, abstinence time, body mass index, caffeine and alcohol intake and
smoking," reads the study.

Men who were obese or overweight, who accounted for 72 per cent of the
study's participants, were more likely to have lowered sperm concentrations,
the study also found.

The 99 participants were recruited from the Massachusetts General Hospital
Fertility Center,
where they were evaluated for sub-fertility between 2000 and 2006.

The researchers believe that the estrogenic properties of soy may negatively
affect the production of sperm, an effect that may be heightened in obese or
overweight men who have higher estrogen levels than men of normal weight.

http://www.cbc.ca/health/story/2008/07/23/soy-spermstudy.html

Last Updated: Wednesday, July 23, 2008 | 7:14 PM ET Comments1Recommend5

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