A new analysis published in the journal, Human Reproduction Update, is showing that the sperm counts of men in North America, Europe, Australia, and New Zealand have markedly declined in the past 40 years.
Researchers from the Hebrew University of Jerusulem conducted a meta-analysis of 185 studies. The studies included data from sperm samples from almost 43,000 men from 50 different countries between 1973 and 2011. Over that 40 year-period, men from industrialized, Western countries were found to have a 52% decline in sperm concentration and 59% decline in total sperm count. There was no decline in sperm counts and concentration for men living in South America, Asia, and Africa.
As a fertility specialist, I can say that this trend seems to be legitimate. Over time, it seems that we’ve been seeing more abnormal semen analyses. We’ve also been seeing more patients who need IVF with intracytoplasmic sperm injection (ICSI) for fertility treatment due to these abnormal sperm parameters.
The cause of the declining sperm counts for Western men is unknown, but it can be speculated that environmental factors play a large role. In Western countries, we are exposed to more chemicals than we ever have been before. Previous studies have shown that certain chemicals, including pesticides and lead and fire retardants, can alter male hormones. In addition, BPA in plastic containers, including plastic water bottles, has been shown to alter sperm production.
It’s also easy to assume that one of the largest contributors to declining sperm counts in Western countries is obesity. Obesity in reproductive age men has tripled over the last 4 decades. There have been several studies linking obesity to decreased sperm counts and male infertility.
Lifestyle factors such as smoking also likely play a major role. Smoking has been shown to have an adverse effect on both sperm production and sperm function. And, it’s not only male smoking that matters. Studies are now showing that women who smoke while pregnant with a male child may be damaging their child’s future fertility.
So, what can we do about this? While exposure to certain chemicals may be out of our control, there are many things we can control. For men, it’s important to live a healthy lifestyle. This includes having a healthy diet and exercise regimen, avoiding toxins such as tobacco and illicit drugs, and limiting alcohol consumption. For more information about optimizing male health and fertility, visit our lifestyle and fertility page.