Eating Soy Associated With Lower Sperm Counts

Researchers at Harvard School of Public Health found that men who consumed a half serving of soy or more per day had lower sperm counts compared to men who consumed no soy. They analyzed the intake of 15 soy-based foods in 99 men who had attended a fertility clinic. The men were questioned on how often they consumed soy products (foods included tofu, burgers, milk, cheese, ice cream, etc) over the last three months. Men who ate the most soy foods had on average 41 million sperm per milliliter less than men who did not consume soy products. (The "normal" sperm concentration for men ranges between 80-120 million/ml). Soy products contain a high amount of phytoestrogens which are plant compounds that can behave like the hormone, estrogen. The researchers speculate that the increased amount of estrogenic activity may have an adverse effect on sperm production. This interference with other hormonal signals may be further strengthened in overweight individuals because men with higher levels of body fat produce more estrogen than slimmer men.