A recent 2008 study which was published in the journal Human Reproduction, found that men who eat products containing soy, have a lower sperm count.
Doctors at Harvard University Medical School studied 99 men who had partners with sub-fertility and who were undergoing investigations to see if they contributed to this sub-fertility. The men's dietary habits over the preceding three months were analysed to see if they had consumed any of 15 different types of soy product.
They allowed for other variables which could affect the results, such as smoking, alcohol and caffeine intake and body weight, but even after these factors were taken into account, a lower rate of fertility was still found in men who consumed soy.
The men were divided into four groups: men with no intake of soy, men with occasional intake of soy, men with regular intake of soy and men who ate large quantities of soy.
41 Million Less Sperm!
Men with the highest intake had a staggering 41 million less sperm per ml of semen. The study authors concluded that:
'These data suggest that higher intake of soy foods and soy isoflavones is associated with lower sperm concentration.'
Other studies have reached similar conclusions. Dr. Lorraine Anderson from the Royal Victoria Hospital in Belfast, Ireland, says she too discovered a link between soy products and declining male fertility.
'What we have shown is that if men are consuming large amounts of soya products, for example, there is a negative relationship between that and the quality of their sperm.
"If they already have a problem in that area, then it's better for them not to consume so much."
Why Would Soy Damage Male Fertility?
Soy contains a plant estrogen called phytoestrogen. Too much phytoestrogen in a man can adversely affect his sperm quality and phytoestrogen supplements have even been sold to men who want a sex change, for the purpose of helping them grow breasts.
You may think that soy is just used for making vegetarian foods, but actually, it's everywhere. It is a common added ingredient in many fast foods. That pepperoni pizza you just ordered may not really be pepperoni. Meat products are routinely substituted with soy because it's cheaper. Microwave dinners and even steak and kidney pie may really be meat padded out with soy.
When was the Last Time You Read the Label?
The vegetarian and vegan community have lashed out at the growing number of studies linking soy to health problems; however, they needn't worry because it isn't the vegetarian or vegan diet which is unhealthy, it is the processed junk food diet that is. A vegetarian could rely on pies from the frozen section and ready meals and that wouldn't make him healthy just because he refrained from eating meat. He would have to eat fresh and whole foods and pay attention to his diet in the same way a meat eater would when trying to attain balanced nutrition. There are so many fast food products out there that the public just buy and eat without looking at the label and they may be ingesting far greater quantities of phtyoestrogens than they previously thought.
Even a pregnant woman's diet and exposure to phtyoestrogens can have an adverse effect on the growing male fetus in her womb and could impact on his future fertility, so awareness of what is in our food, should start ideally before conception of our children.
How can I Reduce Phytoestrogens in My Diet?
Simple - eat fresh! Have lots of fresh fruit, vegetables and grains. Get a recipe book out and cook your meals from scratch. Make that pie instead of buying one from the freezer section. Limit your intake of ready meals and junk foods and check any that you do buy for soy content. A little does no harm, a lot may do.
Joanna Karpasea-Jones - I have been a health writer since 1997 when I published my own newsletter, SHOTS. I have written 2 books on childhood health, and write ...
