CHANGES IN SPERM COUNT AND FUNCTION

The average proportion of spermatozoa with normal morphology decreased from 39.2% to 26.6% between the early and late periods (p<0.0001), and the mean percentage of spermatozoa with rapid progressive motility decreased from 52.7% in the early period to 31.7% in the late period (p<0.0001). [...] The evident stabilization of the decline in sperm motility since 1989-1990 may relate to the reported stabilization of environmental pollution with organochlorine compounds during the past 5 or 6 years. [...] In the earlier French study, sperm concentration, morphology and motility were studied in sperm donations from 1973 to 1992, and a decrease in sperm concentration of 2.1% per year was found, along with significant (p<0.0001) decreases in percentages of motile and normal spermatozoa over time. [...] In addition, a meta-analysis4 of 61 studies also found a trend toward decreasing sperm count over 50 years, along with an increase in the number of men with low (<40 million/ml) sperm counts and a decrease in the number of men with high (>100 million/ml) sperm counts. [...] In a laboratory study at the University of Guelph, Canada12, B-sitosterol was found to significantly reduce concentrations of testosterone and testosterone metabolites in the plasma of male fish, and the effects increased with the higher dose.