Study: Quality of sperm has declined 50 percent in 40 years

Source: www.columbian.com --- Monday, July 31, 2017
The quality of sperm from men in North America, Europe and Australia has declined dramatically over the past 40 years with a 52.4 percent drop in sperm concentration, according to a study published July 18. The research — the largest and most comprehensive look at the topic, involving data from 185 studies and 42,000 men around the world between 1973 and 2011 — appears to confirm fears that male reproductive health may be declining. While a number of previous studies found that sperm counts and quality have been declining, some have dismissed or criticized the studies for things like the age of the men included, the size of the study and other aspects of the selection of the study population. Shanna H. Swan, one of the authors of the new study published in the Human Reproduction Update, said she hoped this broad meta-analysis of all the published literature out there would put some of the uncertainty to rest. “It shows the decline is strong and that the decline is continuing,” Swan said. The analysis found drops only for men in Europe, North America and Australia and not for those in South America, Asia and Africa. Swan explained that this could mean that there’s something specific to certain cultures or countries that affects sperm, but that it’s also possible that there just isn’t enough data yet to draw firm conclusions about the rest of the world. There have been far fewer sperm studies conducted in non-Western countries. Th ...

from Australia http://ift.tt/2tWCnA4