It’s not really news to anyone that smoking is bad for your health; yet, still there are over 6 million people in the UK smoking regularly!
According to the NHS website, around 78,000 people in the UK die as a result of smoking with 70% of lung cancer cases being linked to smoking.
Other illnesses associated with smoking include:
- Coronary heart disease
- Heart attack
- Stroke
- Peripheral vascular disease
- Cerebrovascular disease
The NHS also notes that smoking reduces fertility in women and men and is linked to erectile dysfunction.
So, just to be absolutely sure, we thought we’d dig into the research to see what the science says.
What did the research say?
Well, we didn’t have to look too far to find plenty of damning evidence for smoking and sperm health. What we found was more than enough to confirm that smoking is particularly bad for sperm health.
Interestingly, a lot of research seemed to also focus on alcohol consumption alongside smoking as the two usually go hand in hand. We already know that excessive alcohol consumption is bad for sperm health, so adding smoking on top of that is only going to compound things further. For those who don’t drink, then smoking alone still does more than enough damage.
What seemed to be pretty unanimous amongst the research was that all parameters in a standard semen analysis were lower in smokers compared to non-smokers. Unfortunately, though, the damage didn’t stop there. Sperm DNA damage was also higher in those who smoke. Rising from around 14% to 35% in smokers compared to non-smokers.
What’s at play when you smoke?
Cigarette smoke releases over 2000 toxins including cadmium, lead, arsenic, carbon monoxide and cotinine to name just a few. Cotinine is the primary metabolite of nicotine and it lasts much longer in blood than nicotine. These toxins cross the blood-testis barrier and affect every cellular element of sperm leading to damage within the sperm, an increase in oxidative stress and an increase in sperm DNA fragmentation.
Smoking also increases leukocyte levels by 48%. Leukocytes are a response to inflammation or infection in the body and can release reactive oxygen species (ROS) leading to an increase in oxidative stress and DNA fragmentation.
It’s suspected that high levels of ROS play a big role in the damage occurring to sperm when smoking, but it is also noted that smoking decreases the availability of antioxidants, the natural defence to ROS, within seminal fluid.
How much and how long counts?
One study concluded that the deterioration of sperm quality was directly related to the number of cigarettes smoked per day as well as the duration of smoking. Heavy smoking is classed as greater than 20 cigarettes per day which was where a lot of the research was focussed. However, in some studies, they were seeing the same effects on sperm with less than 10 cigarettes per day.
Even non-smokers are at risk, with DNA damage being linked to passive smoking from second hand smoke.
Conclusion
Really, there isn’t anything good to say about smoking and sperm health. There is more than enough evidence to demonstrate that smoking has a significant detrimental impact on sperm health across all parameters whilst also impacting the DNA in the head of the sperm.
We know that DNA fragmentation has an impact on fertility, ART success rates and ongoing pregnancy success.
Smoking will not only hinder a man’s chances of conceiving, but it will also put any future pregnancy at risk whilst also impacting a child’s future health if a pregnancy is successful. Smoking has been proven to cause epigenetic damage to sperm and thereby to the offspring in terms of low birth weight, metabolic syndrome, leukaemia or childhood cancers to name a few. Epigenetics is the study of heritable modifications that regulate the activity of the genome without altering the DNA sequence, i.e. not causing a genetic mutation.
If you’re a smoker and you need help to quit then the NHS have a wealth of resources that you can access. You may also want to consider talking with your GP or local pharmacist to see what support is available.
Vaping is often considered a better alternative to smoking, which it is, but these things are all relative. Vaping comes with it’s own risks and as a relatively new technology we’re yet to see the long term impact this could have on male fertility.
Going smoke free and vape free is by far the best thing you can do for your health and fertility.
Research reviewed
Amor, H., Hammadeh, M. E., Mohd, I., & Jankowski, P. M. (2022). Impact of heavy alcohol consumption and cigarette smoking on sperm DNA integrity. Andrologia, 54(7), e14434.
KJ Joo et al. The Effects of Smoking and Alcohol Intake on Sperm Quality: Light and Transmission Electron Microscopy Findings. The Journal of International Medical Research 2012; 40: 2327 – 2335 2327
Ranganathan P et al. Deterioration of semen quality and sperm‐DNA integrity as influenced by cigarette smoking in fertile and infertile human male smokers—A prospective study. J Cell Biochem. 2019;1‐10.
Mostafa RM et al. The effect of cigarette smoking on human seminal parameters, sperm chromatin structure and condensation. Andrologia. 2018;50: e12910.
Gunes S et al. Smoking‐induced genetic and epigenetic alterations in infertile men. Andrologia. 2018; e13124