Researchers at Hebrew University in their study, temporal trends in sperm count: a systematic review and meta-regression analysis, have evaluated nearly 200 studies of sperm counts say it has halved in less than 40 years. The case studies were taken from North America, Europe, Australia, and New Zealand.
According to BBC, some experts are skeptical of the Human Reproduction Update findings.
Lead researcher of the study Dr. Hagai Levine said he was “very worried” about what might happen in the future.
The study has assessed 185 studies between 1973 and 2011.
Smoking, stress, obesity, unbalanced foods could result in low sperm count. Photo credit: Natural Health Bag
Dr. Levine who is an epidemiologist, someone who studies and analyze the patterns, causes and effects of health by identifying risk factors for disease defined in population, told the BBC that if this decline continues humans might go extinct.
Researchers are worried about if the rate of this keeps on declining it might increase the rate of infertility.
“If we will not change the ways that we are living and the environment and the chemicals that we are exposed to, I am very worried about what will happen in the future,” he said.
“Eventually we may have a problem, and with reproduction in general, and it may be the extinction of the human species.”
The study found a 52.4% decline in sperm concentration, and a 59.3% decline in total sperm count in men from North America, Europe, Australia and New Zealand. The study also indicated that this rate of decline among men living in these countries is continuing and possibly even increasing.
Some scientists who were not involved in the study praised the quality of the research but also indicated that it’s still too premature to come to such a conclusion.
Although the study was concentrated in North America, Europe, Australia, and New Zealand in contrast to this there have been no significant decline in South America, Asia and Africa, but the researchers include that there has been very few studies conducted in these continents.
Scientists have called some of the previous studies on sperm count flawed. These studies were carried out in the same socio-economic background in developed countries, on the similar topic that has also indicated similar sharp declines in sperm count.
The reason was that some of the studies only investigated smaller number of men, or included only men who attended fertility clinics and in any case more likely to have low sperm counts.
Prof Allan Pacey of Sheffield University said to the BBC: “I ve never been particularly convinced by the many studies published so far claiming that human sperm counts have declined in the recent past.”
“However, the study today by Dr Levine and his colleagues deals head-on with many of the deficiencies of previous studies.”
Natural remedies to increase sperm count. Photo credit: Natural Health Bag
Prof. Pacey believes the study results should be treated with caution, despite the recent study has reduced the possibility of errors in understanding the decline of sperm count in men.
“The debate has not yet been resolved and there is clearly much work still to be done.
“However, the paper does represent a step forward in the clarity of the data which might ultimately allow us to define better studies to examine this issue.”
Dr Levine says that there is an urgent need to find out why sperm counts are decreasing and to find ways of reversing the trend.
“We must take action – for example, better regulation of man-made chemicals – and we must continue our efforts on tackling smoking and obesity.”