Redefining the term 'blue balls': Does termperature affect sperm quality?

Recently, we've noticed a remarkable uptick in the number of Béa customers talking to us about testicular health, and notably, scrotal cooling. What on earth is that we hear you asking? Well, this article is going to dive into this and answer the following questions: Does cooling one's balls really improve sperm quality? Is it time to reclaim and redefine the term ‘blue balls’ in fertility? The short answer is…maybe. 

There is *some* data out there on this topic, but not much. Apparently, the lack of data is mostly due to men’s hesitation to participate in scrotal-themed studies, which isn't great for us as we try to debunk the myths from science. However, we’ve done a deep dive on what little data there is out there so you don’t have to. Here we go...

Does temperature affect sperm quality? Yes. 

There is clear evidence that higher temperatures negatively affect sperm quality. Data from 365 males indicates that sperm motility is significantly reduced if males work or sleep in warm environments, sit for 6+ hours per day, or wear tight-fitting underwear. The scrotum hangs outside the body to keep sperm 2-6 °C below the core body temperature. An increase in body temperature can lead to impaired sperm maturation and subsequent abnormalities in morphology. A very small study that heated testicles showed a dramatic – but reversible – impact on sperm quality. Unsurprisingly, voluntary enrolment was low for that study, so the data set is too small to draw concrete conclusions.

Are our balls actually getting warmer? Jury’s out, but probably, yes.

Some researchers point to global warming as a reason for warmer balls, and poorer sperm. Heat stress does affect reproductive function in mammals. There isn’t yet established causality between global warming and global sperm quality, however. A more likely cause of our toasty testicles is lifestyle factors – tight underwear and jeans that hold the scrotum closer to the body, sitting for 6+ hours at a desk, etc. 

Does scrotal cooling improve sperm? Probably not. 

There isn’t enough data, because patients are ‘not compliant’ with the recommended use of a scrotal cooling device due to ‘comfort, convenience and concealability’. It turns out, most men don’t hugely fancy walking around with an ice pack strapped to their nether regions - which is completely fair. Before we can conclude whether scrotal cooling devices improve sperm quality, we need to design better ones that men will actually wear. There is, however, some data to suggest that scrotal cooling can treat chronic conditions such as a varicocele, or chronic scrotal pain. 

What does help sperm health? Quite a lot! 

New sperm cells are created every 74 days, so lifestyle changes (diet, exercise) on the male side can have a material  – and quick – impact on sperm health. Head to our handy guide for optimising sperm health to find out more.