back to top
Wednesday, 30 April, 2025
HomeEditor's PickHigher sperm quality could be linked to longevity – Danish study

Higher sperm quality could be linked to longevity – Danish study

Men with higher levels of strong, agile sperm may live nearly three years longer than those with poor swimmers incapable of making it to their destination, according to a recent large-scale study that tracked more than 78 000 men for 50 years.

The ability of sperm to properly swim through the female reproductive tract to reach and fertilise an egg is called motility, reports CNN.

“In absolute terms, men with a total motile count of more than 120m (per millilitre of semen) lived 2.7 years longer than men with a total motile count of between zero and 5m,” said lead study author Lærke Priskorn, a researcher and doctoral candidate at Copenhagen University Hospital – Rigshospitalet – in Denmark.

To translate that into ages, a man with extremely poor sperm motility might be expected to live up to 77.6 years, while a man with extremely high motility might survive to 80.3 years, according to the study published in Human Reproduction.

“The fact that there is an association between semen quality and longevity is an important finding,” said Dr Michael Eisenberg, professor of urology and director of male reproductive medicine and surgery at Stanford University School of Medicine, who was not involved in the research.

“Previous studies have also suggested this link between reproductive health and overall health,” he added.

Could sperm count be a ‘canary in the mine’?

In the latest report, the researchers compared the quality of sperm samples taken between 1965 and 2015 from men undergoing infertility testing in Copenhagen. The quality of the sperm was then compared with national medical records gathered by the Danish national health service.

“The lower the semen quality, the lower the life expectancy,” Priskorn said. “This association was not explained by any diseases in the decade before semen quality assessment or the men’s educational level.”

Motility counts are typically provided in percentages, not total numbers. The World Health Organisation considers a man’s sperm normal if about 42% of the sperm in each sample of ejaculate is capable of swimming to its destination.

However, a motility count of less than 5m per ml of semen is associated with a severe case of oligospermia, or low sperm count, which often leads to male infertility, the study said.

A sperm motility of about 125m per ml of semen is normal for a fertile male, Eisenberg said.

However, that doesn’t guarantee male fertility, experts say.

If not for fertility, why would testing semen be a benefit? Because it could also be a marker for male health problems at younger ages, said John Aitken, a distinguished professor emeritus from the School of Environmental and Life Sciences at the University of Newcastle, Australia, who was not connected to the study.

“In men, it appears to be their semen profile that is providing the most significant information concerning their future health and well-being,” Aitken wrote in an editorial published alongside the study.

“If spermatozoa really are the canaries in the coal mine of male health, the obvious question to ask is, why?” Aitken posited. “What possible factors could link the ultimate life expectancy of males with the quality of their semen profile in early adulthood?”

Oxidative stress is one possibility

He said one answer explaining the association might be oxidative stress, caused when free radicals run rampant. Free radicals are unstable molecules that can damage DNA and cellular function and lead to cell death throughout the body, including the testes and sperm.

“Any factor (genetic, immunological, metabolic, environmental or lifestyle) that enhances overall levels of oxidative stress, could reasonably be expected to drive changes in the semen profile and subsequent patterns of mortality,” he said.

Smoking, excessive alcohol, sun exposure, pesticides, industrial chemicals and air pollutants are just a few of the ways free radicals are activated,

The body does have a way to fight back – with antioxidants. These “free radical scavengers” can prevent and repair damage caused by some types of free radicals, experts say.

While supplements have failed to show promise against free radicals, fruits, vegetables, nuts and grains with key vitamins and minerals are excellent sources of antioxidants.

Study details

Semen quality and lifespan: a study of 78 284 men followed for up to 50 years 

L Priskorn, R Lindahl-Jacobsen, N Jørgensen et al.

Published in Human Reproduction on 5 March 2025-03-06

Abstract

Study Question
Is semen quality associated with the lifespan of men?

Summary Answer
Men with a total motile sperm count of >120 million could expect to live 2.7 years longer than men with total motile sperm count of >0–5 million.

Study Design, Size, Duration
The study was based on 78 284 men who had their semen quality assessed between 1965 and 2015 at the public semen analysis laboratory in the Copenhagen area, Denmark, due to reported couple infertility. Thus, the included men covered a wide range of semen quality. Semen quality assessment included semen volume, sperm concentration, and the proportion of motile and morphologically normal sperm, from which the total sperm count and the total motile sperm count were calculated. Utilizing the unique Danish national registers, follow-up of the men regarding all-cause mortality was performed with a median follow-up of 23 years (5–95th percentile: 8–45 years) during which 8600 deaths occurred, accounting for 11.0% of the total population.

Participants/Materials, Setting, Methods
Life expectancy was calculated according to semen quality. Furthermore, the relative differences in mortality were estimated using Cox regression analyses and presented as hazard ratios (HRs) with 95% CIs. A more recent subpopulation of 59 657 men delivered semen samples between 1987 and 2015, a period in which information on educational level and diseases prior to semen sampling was available and adjusted for in Cox regression analyses.

Results
Men with a total motile count of >120 million could expect to live 80.3 years, compared to 77.6 years among men with total motile count of >0–5 million. In Cox regression analyses, all semen parameters were negatively associated with mortality in a dose–response manner both in the total population and the more recent subpopulation (P-trend for all semen parameters <0.001), and adjustment for educational levels and prior diagnoses did not change the estimates in the latter. Looking at total motile sperm count as an example, men with a total motile sperm count >120 million served as the reference, and the adjusted HRs for all-cause mortality in the more recent subpopulation were: azoospermia: 1.39, >0–5 million: 1.61, >5–10 million: 1.38, >10–40 million: 1.27, >40–80 million: 1.16, >80–120 million: 1.19, P-trend < 0.001.

Limitations
The study was well-powered and included a unique database of results from semen analyses combined with register follow-up. However, we did not have information on health behaviours, and assessment of the health of men prior to semen sampling was limited to diagnoses obtained from the National Patient Register, and only applied to a subpopulation of men. A further limitation is that the group of men with azoospermia represents a heterogeneous group regarding testicular function as they could not be stratified into those having obstructive azoospermia and those having non-obstructive azoospermia.

Wider Implications of Findings
We observed clear negative dose–response associations between all semen parameters and all-cause mortality. The associations were not explained by educational levels or diseases registered at the time of semen evaluation. Thus, some men with impaired semen quality may experience less healthy ageing than men with better semen quality and could benefit from being identified at the time of semen quality evaluation. However, finding relevant biomarkers to identify the subgroups of men at increased risk will be key to initiating relevant prevention strategies.

 

Human Reproduction article – Semen quality and lifespan: a study of 78 284 men followed for up to 50 year (Open access)

 

Human Reproduction linked editorial – Spermatozoa as harbingers of mortality: the curious link between semen quality and life expectancy (Open access)

 

CNN article – Sperm quality linked to living longer, new study finds (Open access)

 

See more from MedicalBrief archives:

 

Human sperm rapidly affected by diet — small Swedish study

 

Eating nuts improves human sperm — randomised trial

 

Men’s age more of an impact on fertility than previously realised – UK study

MedicalBrief — our free weekly e-newsletter

We'd appreciate as much information as possible, however only an email address is required.