Here’s What That Sperm Concentration Study Actually Means For Humans
It’s not great news.
By Andrew Stapelton | 29 July 2017
SCIENCE ALERT — 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. …
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.
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 leveling 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. […]