Another journal has published reports of lowered male sperm counts in men with a higher intake of soy isolflavone. This Cross-sectional study, published in UroToday, assesses isoflavone intake in males of sub fertile couples who had a semen analysis conducted. Along with the analysis, the men were given a questionnaire designed to assess intake of 15 soy-based foods in the last three months.
Soy Isoflavones are plant-derived polyphenoloic compounds with weak estrogenic activity; they are found mainly in soybeans and soy-derived products. In previous research, high isoflavone intake has been reported to be associated with decreased animal fertility. The impact of high isoflavone intake on human fertility is unknown, and the subject remains a bit controversial. This Cross-sectional study looked at 100 men with semen data and completed questionnaires. There was an inverse association between soy food intake and sperm concentration that remained significant when evaluated with respect to age, abstinence, body mass, and caffeine or tobacco intake.
This study was conducted at the Department of Nutrition, Harvard School of Public Health (Boston, MA) as well as the Department of Urology, Massachusetts General Hospital Boston, MA. Contributors included Vincent Memorial Obstetrics and Gynecology Service at the Massachusetts General Hospital, (Boston, MA) as well as the Departments of Environmental Health and Epidemiology at Harvard School of Public Health.
This is an area which will undoubtedly be the subject of further investigation.