Smoking and Sperm Quality – The Science Behind It

We need to talk about smoking and sperm quality. Well, all know that smoking is bad for our health, you only have to look at the scary pictures on cigarette packets to work that out. But did you know that smoking is one of worst things you can do for your long term fertility?

Impotence, hormonal imbalances, and dramatically decreased sperm quality are all caused by smoking.

Tobacco smoke contains more than 4,000 chemicals including a myriad of known carcinogens (plus a load of other harmful substances like tar). Exposure to tobacco smoke has a serious effect on semen quality. For example, one study showed that – in a cross-sectional analysis of 2,542 healthy men over 12 years – cigarette smokers had lower sperm quality and sperm count compared to men who didn’t smoke.

The study proves that smoking is a huge factor in male fertility – and that’s without looking at other areas such as impotence and DNA Fragmentation that the bad habit can also contribute to.

If you still need convincing that it’s time to ditch the cigarettes altogether, here’s our scientific breakdown of all the ways smoking is damaging your sperm.

Sperm volume and seminal fluid

Sperm is made up of seminal plasma, the stuff that makes ejaculation fluid. This seminal fluid plays a major role in male fertility, as it provides both nutrition and protection to sperm cells travelling through the female reproductive tract.

The chemicals in tobacco smoke not only lower the sperm volume in your semen but also decreases the protective seminal fluid components. As a result, the sperm cells of smoking have a lower chance of surviving their journey to the egg.

Sperm quality

Several clinical studies have reported that smokers have lower sperm quality compared to non-smokers. In a study including 1,786 men, smoking was associated with a decrease in sperm counts by 17.5% and in total motile sperm cells by 16.6% when compared to non-smokers.

Research also shows that smoking can lead to male infertility through a decrease in reproductive hormones (FSH and testosterone, amongst others), which are essential for sperm production.

Sperm Motility aka Sperm Speed

A sperm cell’s ability to swim (motility) is highly important for overall sperm quality. The better your swimmers are at swimming, the higher their chance of reaching and fertilising an egg.

Smoking increases Reactive Oxygen Species (ROS). ROS are biologically active, oxygen-containing free radicals that have the ability to damage DNA and kill sperm cells. This is called oxidative stress, which you can read more about here. This sperm DNA-damage negatively impacts sperm motility. Therefore, more “bad” swimmers are produced, lowering overall semen quality.

Sperm Morphology – aka Sperm size and shape

When it comes to sperm, size (and shape) does matter. Badly-shaped sperm cells aren’t good swimmers and don’t have the best chances of survival compared to normal looking sperm cells. This means they are less likely to reach and fertilise the eggs, lowering your chance of getting pregnant.

Smoking affects the shape of sperm cells, resulting in structural abnormalities such as curved tails. Several studies confirm that men who smoke have fewer well-shaped sperm cells than non-smokers – so stubbing out is definitely something you should consider if you want to improve your sperm morphology.

Sperm DNA

Besides alterations in sperm shape, size, volume, and quality, some studies have looked into sperm DNA in smokers.

The men who smoke seem to have increased DNA fragmentation (the separation or breaking of DNA strands into pieces), which may be associated with problems of fertilisation and embryo development. Some studies suggest that the DNA fragmentation in the sperm cells even can be transferred to the baby.

Overall, this can also mean that chances of pregnancy are poorer, even with artificial insemination or IVF treatment.

Erectile Dysfunction

Erectile dysfunction or other sexual impairments can have a huge impact on your sex life and make it harder for you to conceive. Several studies show that smoking is associated with a high risk of erectile dysfunction (ED). ED affects around 20% of all men and up to 52% of males aged 40–70 years.

Erections happen when is that healthy blood vessels dilate and get filled with blood. When you smoke, the lungs absorb toxins from the cigarette smoke. Those toxins cause damage to the vessels in the penis and impair blood flow, resulting in ED. Having trouble standing to attention doesn’t necessarily mean that you are producing bad sperm, but if you have ED, it can make sex touch and stressful, which could have a knock on effect on your baby-making plans.

Parental exposure

But smoking doesn’t just impact you in adulthood. There have been several studies that clearly find exposure to cigarettes while in the womb can have an impact on a man’s fertility in the future.

One study of 1,770 men demonstrated that those who had prenatal exposure to smoking had over 20% lower sperm density as adults than those without exposure. Other studies have found lower sperm concentration when making the same comparison.

This is useful to know because if your mother smoked whilst she was pregnant with you, it may be useful to raise this with your doctor if you are having problems conceiving.

It’s never too late – there is hope

Not all is lost – the impact of smoking is quite reversible for most men. So, it’s never too late to quit cigarettes and stop damaging your sperm cells! The process of making new sperm cells takes around 70-90 days. This means that you can see an improved sperm quality around 3 months after you stop smoking. However, it may take a little longer if you have been a heavy smoker for a long time.

Our top tips on quitting smoking

Speak to your doctor – You don’t have to do this alone! Many GPs will be able to offer advice on quitting smoking, put you in touch with support groups or recommend some replacement therapy (like patches or gum) to get you through it.

Share your goal with family and friends – You’ll probably need support from those around you as well as your doctor. Telling people how important quitting smoking is to you will mean they are more likely to help you stay on track.

Clean your whole house and clothes the day you smoke your final cigarette – It can really help to give you that fresh start feeling and adjust your mindset.

Start a piggy bank – Whilst the health benefits are the most important, they are not instant or the most tangible. But starting a piggy bank with all the money you would have spent on cigarettes can give you a boost if you are finding it tough!

Track your sperm health progress with ExSeed – You can use the ExSeed at-home testing kit to see how your sperm is improving thanks to quitting! This should give you some encouragement to keep going.

ExSeed Health not only analyses your sperm but also help you to start your smoke-free and improved life with our lifestyle programs. Make sure to check them out!