Soy-based foods may lower sperm count

Courtesy of Associated Press

Eating a half serving a day of soy-based foods could be enough to significantly lower a man's sperm count, U.S. researchers said on Wednesday. The study is the largest in humans to look at the relationship between semen quality and a plant form of the female sex hormone estrogen known as phytoestrogen, which is plentiful in soy-rich foods. "What we found was men that consume the highest amounts of soy foods in this study had a lower sperm concentration compared to those who did not consume soy foods," said Dr. Jorge Chavarro of the Harvard School of Public Health in Boston, whose study appears in the journal Human Reproduction. "It was a relatively large difference."

Chavarro's team analyzed the intake of 15 soy-based foods in 99 men who went to a fertility clinic between 2000 and 2006. They were asked how much and how often in the prior three months they had eaten soy-rich foods including: tofu, tempeh, tofu or soy sausages, bacon, burgers and mince, soy milk, cheese, yogurt and ice cream, and other soy products such drinks, powders and energy bars. Men in the highest intake category had 41 million sperm per milliliter less than men who ate no soy foods. A normal sperm count ranges from 80 million and 120 million per milliliter, and a sperm count of 20 million per milliliter or below is considered low. "It suggests soy foods could have some deleterious effect on the reproductive system and especially on sperm production," Chavarro said.

The researchers found the association between soy foods and lower sperm count was stronger in overweight men, which might suggest hormones are playing a role. "Men who are overweight or obese tend to have higher levels of androgen-produced estrogen. They are converting a male hormone into a female hormone in their fat. The more body fat you have, the more estrogen you produce in your fat," Chavarro said. Chavarro said the study was not sufficient to suggest that soy intake would have health implications such as inducing infertility. Much bigger studies would be needed to answer that question, he said.

Bonnie - while this was a small study, the results should come as no surprise to clients of mine. Men are over-estrogenized as it is without soy in their diet. Eating soy foods on a daily basis, especially during fertile years, is not recommended.

It also should come as no surprise that men who weighed more had lower sperm counts. The greater the fat mass, the greater the estrogen count, because fat stores estrogen.

Men should be eating or supplementing with estrogen detoxifiers from the cruciferous vegetable family, either in the form of broccoli, cauliflower, brussels sprouts, etc., or in maca, D-Indolemethane, or Indole-3-Carbinol via supplements.