Sperm concentration of western man has diminished significantly
The concentration of sperm cells in an ejaculation of western men, within a time period of around forty years with more than half decreased.
This is evident from a meta-analysis by an international team of researchers from Denmark and the United States, published in the scientific journal Human Reproduction. To do this, they have have viewed 185 studies on male fertility which have been held between 1973 and 2011.
It comes to a decreased sperm concentration of collect 52.4 percent (an average of 1.4 percent per year). In the same period, the number of sperm in an ejaculate with 59,3 per cent. Normally are 100 to 200 million sperm cells in an ejaculation of three to five milliliters of semen.
It comes to the sperm of men from North America, Europe, Australia and New Zealand. There was no striking difference found in the semen of men from South America, Asia and Africa, where much less studies have been held about the fertility of men.
The figures indicate that more and more men with reduced fertility or even infertile. From other recent studies, decreased sperm concentration is associated with a higher risk of certain diseases and even premature death, according to the researchers, also reason for great concern.
“A decrease in sperm concentration in men was 25 years ago for the first time reported”, says Shanna H. Swan, who is also in the study was involved. “For the first time, it has now been demonstrated that decrease continuing, and moreover in a disaster pace.”
“This research makes the alarm bells ringing for researchers and health authorities to identify the causes of this great decline to investigate,” said doctor Hagai Levine, principal investigator of the study.