Biology

Trending Science: Western men’s sperm count plummets over 40 years

Shocking new research suggests that Western men’s sperm count has more than halved between 1973 and 2011, an average of 1.4 % per year. Scientists are still uncertain as to the cause of the dramatic drop but have argued that their findings must be taken seriously and that action must be taken to address what could become a major public health crisis.

A new study published in the journal ‘Human Reproduction Update’ has sounded the alarm bells after showing that since the 1970s, the concentration of sperm per millilitre of semen amongst men from North America, Europe, Australia and New Zealand fell by nearly 60 %.

The findings are particularly alarming as they show that the problem shows no sign of levelling off, so the portion of men who are either subfertile or completely infertile will likely increase, meaning more couples will struggle to conceive. In some Western societies already dealing with the challenges of population stagnation or decline, such as Italy and Germany, this will only add to their long-term demographic woes.

More pressing, lower sperm count predicts an overall shorter life expectancy and are associated with certain forms of cancer and sexual development disorders.

‘The results are quite shocking,’ commented Hagai Levine, an epidemiologist and lead author of the study from the Hebrew University of Jerusalem. He argues that although IVF treatment can offer solutions for successful conception, little has been done to address the root causes of the problem. ‘This is a classic under-the-radar public health problem that is really neglected,’ he added.

The study, the largest meta-analysis ever done on the issue to date, examined data from 185 studies between 1973 and 2011, covering nearly 43 000 men. The team split the data based on whether the men were from Western countries or from elsewhere. After taking factors into account such as age and how long men had gone without ejaculation, they found that sperm concentration had fallen from 99 million per ml in 1973 to 47.1 million per ml in 2011.

The danger of falling sperm counts has often been peddled as a myth, with sceptics arguing that previous research was based on skewed samples because men are more likely to get their sperm examined if they fear they are already infertile. The new study overcame this criticism, as it looked at primarily young men who had never conceived and had no idea about their fertility status.

In contrast, no such trends were seen for non-Western men, although the authors of the current study caution that there haven’t been enough major and substantial studies undertaken in other countries. However, a 2016 study of 30 000 men in China’s Hunan province found that sperm count had declined 18 % between 2001 and 2015. The authors of that study argued that environmental pollution could be to blame.

Unfortunately, the jury is still out on what is causing the phenomenon amongst Western men. Echoing the suspicions of the Chine se study team, public health advocates fear that chemicals such as those in pesticides, flame retardants, cosmetics and plastics are to blame. These substances are known as ‘endocrine disruptors’ as they can interfere with the body’s hormone systems and Western societies are saturated with them.

More research will undoubtedly need to be conducted over the coming years to address a public health issue that could have devastating consequences for future generations.

last modification: 2017-07-28 17:15:02



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