What will give you a longer life in a few years? Sperm swimming briskly to their destination, scientists have shown
Extensive research with clear results
In a study that involved analysing samples from nearly 80,000 men followed for 50 years, Danish researchers looked at how the amount of active sperm translates into life expectancy. The connection between these two topics may seem quite disjointed at first, but the fact is that it builds on a clear logic: semen quality reflects a man's broader health, and consequently the likelihood that he will succumb to health problems later in life.
And what is the main conclusion? Men whose bodies could produce more than 120 million active, swimming sperm in a single batch of semen (this ability to properly navigate the female reproductive system to an egg and then fertilise it is called motility) lived on average two to three years longer than men whose sperm contained fewer than 5 million of them. The average age of the men with the best quality sperm was 80.3 years - compared to 77.6 years for men whose sperm was not as good. "It really does seem that the better the quality of the semen, the higher the life expectancy," summarised one of the study leaders, Dr Lærke Priskorn, directly. According to professor of urology, Dr. Michael Eisenberger, who was not involved in the research, his colleagues' revelation demonstrating the link between semen quality and longevity is then very important.
What is "normal" in the world of sperm?
Over the past 50 years, according to the medical literature, the number of sperm contained in the ejaculate has decreased by more than 50%. And they say this could have major consequences for human reproduction. However, there is a rather ambiguous expert consensus on the subject - while some scientists consider these results alarming, others are not convinced by the data that a reproductive crisis is around the corner - because sperm counting methods have changed so much in five decades that a de facto comparison of historical and current data is impossible. According to another specialist, Dr. Alexander Pastuczak, the reality may even be quite different - since modern studies use modern and different analyses, Pastuczak even claims that many studies, especially from northern Europe, suggest the exact opposite, i.e. that sperm counts in semen are increasing over time.
And what about the "normal" numbers of viable sperm (hence their motility) or the quality of the semen? According to the World Health Organization (WHO), male ejaculate is "normal" if each sample contains approximately 42% of sperm capable of reaching its destination. According to Dr. Eisenber, the normal concentration of sperm in semen for a healthy man is then about 125 million/1 ml. However, this is not an unequivocal guarantee of fertility. At the other end of the spectrum, if the concentration is less than 5 million/1 ml, it is already a serious oligospermia, which leads to infertility.
Zdroj: Giphy
Why does semen quality decrease?
Finally, it is appropriate to return in an arc to sperm quality and male health. Considering that this relationship has already been proven, in fact, one could also say that perhaps today's male population is also not as healthy as it used to be - but the question is WHY. After all, scientists have also looked at possible associations of semen quality with other influences - and the link between poor semen quality and earlier death was not objectively explained by any diseases diagnosed in the ten years prior to testing, nor by education level, which usually reflects socioeconomic status and to some extent lifestyle factors (smoking, diet, exercise).
There are several theories in this case. Possible causes could be genetic defects on sex chromosomes, a compromised immune system, various concurrent problems such as heart disease, lifestyle factors and exposure to pollutants. Reproductive biologist Prof John Aitken believes that so-called oxidative stress could be to blame, where free radicals damage the quality of sperm and body tissue, and in this way also accelerate ageing.
However, there is no really definitive answer, at least not yet, "No one has come up with a satisfactory explanation. It is possible, perhaps, that some as yet unspecified health problem early in life leads to poorer semen quality in younger men and poor health later on. Either way, we need to look at the underlying reasons in future research," concluded Professor of Andrology Allan Pacey. However, he also reassures men with poorer semen quality - he says they should not panic but discuss their concerns with experts. Younger men in particular should talk to fertility specialists, while older ones should definitely not neglect health prevention and other screening tests.
