You can run low on toilet paper, beer, or salsa. But running low on sperm is a whole another level of concern. Good swimmers (sperm and not Olympic backstrokers) are essential for humans to propagate, unless some of you have learned how to split into two to multiply, reported Forbes (US). However, Houston and humanity, we may have a problem. According to a study just published in Human Reproduction Update, between 1973 and 2011, sperm concentration and count dropped by more than half in North America, Europe, Australia, and New Zealand. An international multi-institutional research team led by Hagai Levine from the Hebrew University of Jerusalem performed a systematic review and meta-regression of scientific studies published between 1981 and 2013 and written in English that measured sperm concentration and total sperm count. This meant searching for every study that they could find, clumping them together, and then looking for trends over time. They ultimately found 185 studies of 42,935 men who provided semen samples from 1973 to 2011. Their analysis found that during this time period sperm concentration declined an average of 1.4% per year for a total decline of 52.4%. During the same 38-year time period, total sperm count dropped an average of 1.6% per year for an overall decline of 59.3%, or from 99.0 million sperm per milliliter of semen down to 47.1 for all men in "Western" counties. Projecting these trends for North America, Europe, Australia, and New Zealand would mean that within 7 years the average sperm count could drop below 40 million per milliter, the threshold at which monthly chances of reproducing drop, according to study from The Lancet. Again, this assumes that the same trends continue. Additionally, within 25 years, the average sperm count could drop below thresholds needed to reliably reproduce (less than 15 million sperm per milliliter is the threshold for a lower than normal sperm count, as indicated on the Mayo Clinic website). That's less time than The Simpsons have been on TV. D'oh! This isn't completely new news but rather the latest study in an ongoing running...er rather swimming debate. Back in 1992 Elisabeth Carlsen, Aleksander Giwercman, Niels Keiding, and Niels E Skakkeblek from the University of Copenhagen published a similar study in the BMJ that found that: "there has been a genuine decline in semen quality over the past 50 years." Thus, this latest Human Reproduction Update suggests that twenty years after Carlsen, Giwercmann, Keiding, and Skakkeblek's warning, the downward trends have not leveled off and instead continued. Not everyone has gotten excited about the 1992 study or this latest study. Yes, meta-regressions have a lot of limitations. The collected studies did not measure the sperm counts of everyone in the World or even North America, Europe, New Zealand, and Australia. (What you didn't get the memo to provide a sample?) Thus, the men providing sperm samples could be a select population, such as those visiting fertility clinics. Also, meta-regressions clump together a salad bar of studies from different populations, locations, time frames, and conditions. Some of the studies were larger than others. Some were of better quality than others. Moreover, techniques for measuring sperm concentration and count have changed and improved over the years. Nonetheless, regardless of these limitations, such a large drop in measured sperm counts deserves a closer look at what may be happening. Three years ago, Dr. Phil Hammond wrote for The Telegraph that the cause of the sperm counts dropping is not clear and "could be diet, environment, or girl power." He also said that remembering TAPDANCE can help you keep your swimmers swimming. No, not actually tapdancing but the following mnemonic: - Try not to overdose on your partner’s contraceptive pills - Air your genitals at every socially acceptable opportunity - Piping hot baths are out - Don’t go swimming in untreated sewage - Avoid radiation, industrial cleaners and children with mumps if you haven’t had it - No tight G strings - Let ‘em hang - Cut down on the things you associate with pubs (smoking, excessive alcohol, unprotected sex with strangers) - Eat whatever you fancy until we’ve got more evidence Assuming that girl power is not the culprit and that there isn't an epidemic of men wearing G-strings, the increasing chemicals in our food, on our bodies, and in our environment could be at fault. Indeed, there is a growing body of evidence that pollution can affect sperm. For example, a study in Human Reproduction found differences in sperm movement and count in tollbooth workers who are regularly exposed to car exhaust compared to others who lived in the same area. As another example, a study published in Food and Chemical Toxicology found that giving rats propyl parabens, a chemical commonly used as preservatives in foods, cosmetics, toiletries and pharmaceuticals, resulted in decreased daily sperm production and efficiency. An additional possible cause is increasingly stressful lives, but can this really fully explain the historical trends? A study published in Fertility and Sterility showed that stress had effects on sperm motility and morphology but not concentration. What then should be done besides airing your genitals at every socially acceptable opportunity (which may not necessarily be advisable anyway)? Dropping sperm counts could be a sign that there are just too many chemicals, artificial ingredients, and pollution in our every day food, products, and lives. We need to have a better understanding of how different chemicals and food ingredients may be affecting bodies. If the same trends continue without finding and reversing the causes, our world could be facing greater fertility problems in the not-so-distant future, which could threaten our future. Who knows, marches against artificial ingredients and pollution could end up being really be Marches for Sperm.
Want to be a reporter or would you like to buy a report for the best price?
Just Sign Up here!