Entering ChinaA new study involving nearly 80,000 men has found a strong link between semen quality and longevity. The study was published today (March 5) in Human Reproduction, one of the leading journals on reproductive medicine. The study, which followed participants for up to 50 years, found that men with a total motile sperm count (motile sperm) of more than 120 million lived an average of 2 to 3 years longer than men with sperm counts between 0 and 5 million.
This is the largest study to date to examine the relationship between semen quality and mortality. An accompanying editorial called it a “landmark” publication.
The study was done by Dr. Lærke Priskorn and Dr. Niels Jørgensen from the Department of Growth and Reproduction at Copenhagen University Hospital-Rigshospitalet. They analysed data from 78,284 men who had undergone semen analysis at a public laboratory in Copenhagen between 1965 and 2015, mainly for fertility reasons. The quality of the semen of these men varies widely, some are very high, and some have no sperm. Measurements include semen volume, sperm concentration, motility (motility), and sperm shape.
During the follow-up period, the researchers used data from Denmark’s unique national register to see how many people died from various causes. During this period, a total of 8,600 people died, or 11% of the men in this group. Of this group, 59,657 men provided semen samples between 1987 and 2015, and for this group we can provide more information, including the level of education as an indicator of socioeconomic status, and the diagnosis of the disease registered in the decade prior to the provision of the sample.
The researchers adjusted their analysis to account for additional information from men who had provided samples from 1987 onwards, as this could affect the results.
“Previous studies have shown that male infertility and decreased semen quality may be associated with mortality,” says Dr. Priskorn. We conducted this study to validate this hypothesis while obtaining an absolute estimate of semen quality on male lifespan prediction and to see if diseases diagnosed prior to semen quality assessment could explain some of the associations reported. “
“We calculated men’s life expectancy based on semen quality and found that men with the best semen quality lived an average of two to three years longer than men with the lowest semen quality. In absolute terms, men with more than 120 million total vitality numbers live 2.7 years longer than men with total vitality numbers between 0 and 5 million. The lower the semen quality, the shorter the life expectancy. This association cannot be explained by any illness or male education level in the decade prior to the assessment of semen quality”. “
Dr. Nils Jorgensen. Image credit: Dr. Nils Jorgensen
Researchers believe that poor semen quality may be an indicator of other potential factors that affect fertility and overall health. This has the potential to detect health problems when men undergo semen quality tests.
“We need to better understand the relationship between semen quality and general male health,” Dr. Jorgensen said. However, this study suggests that we can identify a subset of men with impaired semen quality who are ostensibly healthy at the time of semen quality assessment but are at increased risk of developing certain diseases later in life. “
“Therefore, fertility assessments, usually done at a relatively young age, will be an opportunity to detect and reduce the risk of other long-term health problems. In the current study, we did not analyze whether poor semen quality was associated with earlier death from specific causes, such as cancer or heart disease, which is something we will look into in the future. We will also try to identify relevant biomarkers using other male populations to identify male subpopulations at increased risk. This is the key to initiating relevant prevention strategies. “
The advantage of this study is its large scale. Deficiencies include: lack of information on health behaviors; Assessment of the health status of men prior to semen sampling is limited to diagnoses obtained from the National Patient Registry and only for men for whom samples have been available since 1987; It is not possible to distinguish between men who have no motile sperm due to obstruction of the reproductive tract and men who have no motile sperm for other reasons.
John Aitken, a distinguished professor emeritus at the School of Environment and Life Sciences at the University of Newcastle in Australia, called it a “landmark” paper in a commentary accompanying the paper and shed light on various mechanisms that could be associated with poor semen quality and shortened lifespan.
“In this review, I highlight several potential vectors of this association, including genetic defects on the sex chromosomes (X or Y), impaired immune systems, comorbidities, lifestyle factors, and chemical contaminants capable of compromising telomere integrity.” “Given the complexity of these factors,” he writes, “we can’t help but ask: do they act independently, or do they reflect the presence of some fundamental pathological process that runs through all these epidemiological pathways? “
There may be a process called oxidative stress in this process. This is an imbalance between molecules called “free radicals” in the body and antioxidants that inhibit oxidation. Free radicals are known to damage cells and affect semen quality, while oxidative stress has been linked to the aging process.
“As observed by Priskorn et al., any factor (genetic, immune, metabolic, environmental, or lifestyle) that raises the overall level of oxidative stress has the potential to cause changes in semen status, which in turn can lead to death………………. . . . In addition, the etiology of oxidative stress may explain the …… relationship between pregnancy complications (preeclampsia, gestational hypertension, and gestational diabetes) and later mortality in women. The total oxidative stress hypothesis also conforms to the observation that circulating antioxidant levels are generally higher in women than in men, just as they are …… in their telomeres that are typically longer. Thus, for both sexes, the secret to achieving high fertility and healthy ageing may be to monitor oxidative stress and take measures to maintain a balanced redox state. Is it that simple? Obviously, it’s worth pondering. “
