Image courtesy Medical News Today

Men worldwide are producing substantially less sperm than they were decades ago and the rate of decline is increasing in a long-term trend that could even present an existential threat to the future of mankind, a new study suggests.

These alarming findings were published earlier this week in the journal Human Reproduction Update based on a global study, the largest of its kind to be conducted to date.

Sperm Concentration 50 Year Decline

The study found that average sperm concentration and counts over the last 50 years have declined by 62.3 percent.

An earlier study in 2017 had been undertaken in Europe, North America and Australia. The latest study however, extended across Africa, Asia and South America, overall analyzing the results of over 250 studies in 53 countries.

The results confirmed the worldwide trend found five years ago but with the rate of decline accelerating since the year 2000 from 1.2 percent per year prior to that, to 2.6 percent since the millennium.

In the last 5 years the study observed, the average concentration of sperm reduced from an estimated 101.2 million per milliliter to 49.00 million, a fall of 51.6 percent.

Sperm Quality in Kenya

Men in Kenya are in no way exempt from the worldwide trend towards an inability to produce ‘quality sperm’.

Quoted in The Sunday Standard (November 20) Dennis Chalo, a researcher at the Kenya Medical Research Institute (KEMRI) said, “The number of men presenting the inability to produce sperm almost doubled within five years”.

The most common problem, affecting one-in-four men in Kenya, is a low sperm count. A further 14 percent, it has been found, do not produce sperm at all, almost twice as many as was the case in 2013 based on figures from the Kenyatta National Hospital.

Why is Sperm Quality Declining?

Dennis Chalo put the decline down to, in part, to a rise in sexually transmitted diseases, particularly gonorrhea.

Other reasons cited for the decline in sperm production and quality lifestyle changes and environmental factors, increased alcohol consumption, smoking, obesity and poor diet.

Quoted in the UK newspaper The Guardian, Tina Kold Jensen from the University of Southern Denmark, said: “The study should serve as a wake-up call for researchers, clinicians, governments and the public, to confront the reduced sperm crisis by investing in research for both unknown causes and mitigating the known causes.”