It takes two to tango, so they say and this is definitely true when it comes to trying to conceive. Male infertility accounts for around 50% of infertility in couples.
Why is this?
A 2017 study conducted at the Hebrew University of Jerusalem, Israel, revealed that the concentration of sperm in the ejaculate of men has fallen dramatically. The study looked at men in western countries between 1973 and 2011. The data revealed a drop of around 1.4% a year, so an overall drop of 52% in just under four decades!
The reason for this decline in semen quality isn’t defined because male infertility isn’t studied as frequently as female infertility. Researchers have suggested several possibilities; these include body weight, smoking and endocrine disruptors. The last factor is attributed to the exposure of pregnant women to chemicals now commonly found in the environment.
Let’s take a quick look at the aspect of body weight.
In parallel with the decline in sperm quality, the west has seen an increase in male obesity and general weight gain. This is a function of changing lifestyles as working life for men has become more sedentary, otherwise known as sitting at a computer terminal and snacking.
As one researcher puts it, “Possible reasons for the decline of fertility parameters can be the rapidly changed lifestyle, altered physical activity and eating habits along with other factors. A western lifestyle is conducive to weight gain.”
In fact, the prevalence of overweight and obese men is increasing worldwide, with up to 70% of men over 18 classified as overweight or obese in some western nations
So how might this be a contributing factor to male infertility?
There are a number of possibilities here:
- Testosterone: Increased Body Mass Index in males is associated with decrease in testosterone, the male sex hormone, which is used as one of the clinical markers for male fertility
- Sperm function: Male obesity is thought to possibly impair sperm function, including sperm count and motility. This has certainly been shown in animal studies, but is less clear in current human studies, highlighting the need for more research
- DNA damage: There is a clear consensus in current literature that male obesity is associated with higher levels of sperm DNA damage – 10 out of 12 studies show an increase.
This correlation between male infertility and increased weight is also seen at the clinic level. Kristel Ehala-Aleksejev, Researcher, Tartu University Men’s Clinic, Estonia said, “At an andrology appointment, we often see links between weight and fertility. An important factor with men is the accumulation of fat in the waist region. However, central obesity is a great health risk. In addition, obesity as a change in the hormonal balance promotes the development of erection problems, which in turn reduces fertility.”
In her doctoral thesis Ehala-Aleksejev looked at both fertile men and the male partners of infertile couples. Comparing the groups showed that a significantly higher prevalence of obesity was found among the male partners of infertile couples.
She concluded, “They should try to keep physically active, move, and if possible, do sports. They should include more fruit and vegetables and whole-grain products in their diet. Smoking and excessive alcohol consumption are notable risk factors of infertility. However, mental health or ability to alleviate stress and finding time for themselves and their loved ones is no less important.”
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