Scientists have conducted the first large scale systematic review of sperm count and quality and were ‘shocked’ at what they found. The study found that for males from western countries, North America, Europe and Australia, sperm concentration had declined by 50 percent in less than 40 years and should be a wakeup call to solve what’s causing the trend.
“Given the importance of sperm counts for male fertility and human health, this study is an urgent wake-up call for researchers and health authorities around the world to investigate the causes of the sharp ongoing drop in sperm count, with the goal of prevention,” said Hagai Levine, one of the researchers from the Hebrew University of Jerusalem.
Sperm concentration (or sometimes just ‘sperm count’) is the best indicator of male fertility and measures the concentration of sperm in a man’s ejaculate. Another useful measurement is the total sperm count which is the sperm concentration multiplied by volume.
Checking the quality of your sperm is actually now as easy as taking a ‘sperm selfie’ and anything over 15 million sperm per millilitre is considered normal.
Low sperm counts can be linked to poor heath, often diet and lifestyle related, and might even be an indicator of a higher chance of death.
Since 1992, researchers have been aware of the decline in sperm count, but due to limitations of individual studies the conclusions remained controversial.
A team of scientists performed the first ever systematic review and comprehensive meta-analysis of the literature and found that in western studies there was a 52.4 percent decline in sperm concentration and a 59.3 percent decline in total sperm count between 1973 and 2011.
This was even after controlling for factors like age, time after last ejaculation and the demographic that each study looked at.
The team screened 7518 studies and included a total of 244 estimates of sperm concentration and total sperm count from 185 studies of 42,935 men who provided semen samples.
More recent studies didn’t paint a pretty picture either.
When limiting the meta-analysis to studies after 1995, the team found no indication that the decline in sperm count was levelling off.
The findings reported in the study are an ominous sign for the future of male fertility and indicates that there may be a significant health crisis looming on the horizon for western countries.
Scientists are still unclear of what is causing the decline in sperm count but think increased exposure to chemicals may be playing a role.
But does this mean that humans are on a path to a fertility disaster, perhaps leading to extinction?
Shaun Roman, a scientist not involved with the study from the University of Newcastle in the UK, thinks we are not in panic stations just yet.
“It should be noted that it only takes one sperm to fertilise an egg and, on average, western men are still producing 50 million per ejaculate,” said Roman.
“We are not in crisis yet but this study serves as a warning that we should investigate the role our diet and environment pay on sperm production
So, men. Think twice before you order fast food and forego that brisk beach walk – your sperm will thank you. Failing that, maybe scientists can just make you some.
The results were reported in Human Reproductive Update.