According to a study in the July 25 issue of the journal Human Reproduction Update, male reproductive health is in serious decline. Sperm counts in Western countries have decreased by an average 52 percent between 1973 and 2011, while total sperm count declined by 59 percent during that period, according to data analysis from 185 studies involving nearly 43,000 men in all.
“We found that sperm counts and concentrations have declined significantly and are continuing to decline in men from Western countries,” said senior researcher Shanna Swan, a professor of environmental medicine at the Icahn School of Medicine at Mount Sinai in New York City. “The declines are strong, significant and continuing,” she said.
The new findings come on the 25th anniversary of the first study to observe a decline in sperm counts, Swan said. The original study, published in 1992, found that sperm counts had declined 50 percent over 50 years. “The story has not changed over the past 25 years. Whatever is going on, it’s not transient and it’s not disappearing,” Swan said. “When we look at the data for the last five or 10 years, we don’t see a leveling off of this decline.”
No one knows why sperm counts continue to decline, but researchers believe it’s likely due to factors associated with a modern lifestyle, Swan said. These factors include exposure to man-made chemicals, increased levels of stress, widespread obesity, poor nutrition, lack of physical exercise and smoking.