30 July, 2017
Specifically, the researchers found a 52.4-percent decline in sperm concentration and a 59.3-percent decline in total sperm counts in those areas.
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.
Sperm counts among men in Western countries have dropped considerably in the last several decades, according to a new study.
The analysis was conducted by researchers from the Hebrew University-Hadassah Braun School of Public Health and Community Medicine and the Icahn School of Medicine at Mount Sinai using a total of 185 studies which included 42,935 semen samples provided between 1973 and 2011.
The researchers did not find a similar decline in sperm counts among men living in South America, Asia and Africa.
Other fertility experts described the findings as "shocking" and warned of a "double whammy" caused by the combined effects of falling sperm count and women in modern societies waiting until their 30s to get pregnant. It is assumed though that it has to do with obesity, stress, diet, smoking, watching TV (yes, even that) and contact with chemicals that are used in plastics. For example, the sperm counts of each man were assessed at a single time rather than repeatedly over many years.
However, Professor Rob McLachlan, from the Hudson Institute of Medical Research in Melbourne, said it was "too soon to know if the fall in sperm count would be reflected in natural conception rates", reports ABC News.
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. "Because of the significant public health implications of these results, research on the causes of this continuing decline is urgently needed", the study's authors write.
The report, published by Human Reproduction Update on Tuesday, is the work of Israeli, American, Danish, Spanish and Brazilian researchers who reviewed nearly 200 studies done in different places and times since 1973.