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Why is sperm count decreasing?

Male Fertility Myths And Facts

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Over the last 50 years, we’ve seen incredible medical breakthroughs and health improvements in many parts of the world. So it might be surprising to hear that one thing is getting steadily worse: male fertility. Average sperm count has been decreasing bit by bit every year, with no signs of stopping – but why?

Here we’ll go over some of the causes, and what you can do to break this trend.

How do we know sperm count is decreasing? 

The reality is that this decrease is not new, and it’s not the first we’re hearing about it. In 1992 the British Medical Journal published a Danish study into the decline of sperm quality between 1940 and 1990. They reported a 50% decrease in average sperm counts. This sparked not only research into how or why this was happening but also a debate into whether or not it was happening at all. 

Since the 90s, there have been more direct studies into whether or not sperm count and quality was decreasing in the average healthy man. And the results aren’t great. A large meta-study reviewing data from research all over the world found that sperm count is definitely dropping. Between 1973 and 2011, sperm counts have decreased 50-60%. That’s around 1% decrease per year.

Why is sperm count decreasing?

The question is no longer if sperm count is decreasing, but why.

Well, over the past five decades we’ve seen technology, and consumption explodes in rich and developing countries. More food, more roads, more buildings, more of everything. It’s no secret that this is causing a tonne of issues for the planet and our overall health, but people are less aware of the impact on fertility. The reality is that there are a lot of potential causes, and it’s likely the combination of factors that is damaging sperm.

Modern Lifestyle Factors

Staying still more

Far less people are taking on physical or labouring jobs and instead we see a lot more stationary jobs. There’s a lot of admin to do in the world, and on the whole it usually pays better than manual labour. But this is leading to a decline in health, and it’s not even just about the job. 

Physical exercise is great for your reproductive health. It boosts testosterone levels, gets your blood flowing, and overall has a really impressive impact on sperm parameters. You can read more in our blogs “Improving Male Fertility With Exercise” and “The Best Exercise For Male Fertility”.

And altogether this isn’t just to do with work that involves sitting at your computer. If the average person has to spend 8+ hours working 5 days a week, that can take a lot of energy. Many people have to work multiple jobs to make ends meet, so that’s even less free time. Then factor in cleaning, cooking, shopping, taking care of any kids you may have (and something vital that takes up a lot of time: sleep!) time to exercise disappears pretty quickly.

Eating more junk food

Sperm are really intricate little cells that carry human DNA, and your diet plays a big part in making those cells. Your body needs its filling of nutrients to function and produce sperm, which means lots of whole foods, grains, nuts, fruits, vegetables and fish. The issue is that many modern day diets don’t really cut it.

We can see that sperm quality has decreased mainly in the West, and that falls in line with a significant diet change in Western countries. Carbs, processed meat and vegetables, foods with high salt and sugar contents are just common staples. People are also eating more food, but still not getting enough nutrients. This is leading to a lot of health issues such as obesity, diabetes, and heart disease. But even if you’re not experiencing these conditions, your diet may be wreaking havoc on your sperm.

It’s easy to forget about what we put in our mouth. Junk food is also cheap, readily available and it tastes good. Working on your diet can take a lot of time, money and know-how that some people just don’t have. The great thing is that your diet is something you can make changes to when you recognise the issues, and your sperm quality can improve pretty quickly in response. If you’re trying to get your nutrition on the mend, read our blog: “Fertility Diet | Foods To Improve Your Fertility”.


“The typical modern lifestyle in the West is creating unnecessary stress and unbalance of  reproductive hormones, making it more difficult for males and females to have good fertility. Unless our exposure to junk food and toxic chemical contamination begins to decrease, it is unlikely that the prevalence of infertility will decrease”

Dr Fatin Willendrup, Head of Medical Affairs at ExSeed Health

Environmental factors


We use plastic pretty much every day, from the packaging for our food and clothes to the coating on our pens and books. We know that plastic is polluting nature and wildlife, but it’s also harming human health. In terms of fertility, the chemicals around plastics are the real culprit. 

Dr Shanna Swan has been monitoring the impacts of chemicals on male fertility for over 20 years. She says “[chemicals] that can interfere with or mimic the body’s sex hormones – such as testosterone and oestrogen – because these make reproduction possible. They can make the body think it has enough of a particular hormone and it doesn’t need to make any more, so production goes down.”

According to Dr Swan, a lot of these issues occur in utero. Pregnant mothers come into contact with phthalates (chemicals used to soften plastic and so are in our foods that come in plastic wrapping), and this affects the fetus. Anogenital distance (AGD) is the distance from the anus to the genitals, and is larger in males than females. In her study, Swan found that phthalate exposure correlated with boys born with shorter AGD. Males with shorter AGD are more likely to have lower sperm counts. So the impact of phthalates is just one example of chemical damages.


Air pollution is ever-present in most countries, and has a lot of detrimental effects on our health. One of the lesser known impacts is on male fertility. 

Air pollutants such as carbon dioxide, sulfur dioxide, and lead are taking a toll on male fertility. In a large META-ANALYSIS, etc etc found that the compounds in the air can disrupt the production of sperm. Compounds in the air pollution have been shown to fragment sperm DNA, change hormone levels, and decrease overall sperm motility.

These aren’t things that individuals can change. The negative impacts on fertility is just another reason to get behind sustainable development and clean energy. For yourself, you can recycle, try to avoid plastics and spend time in the countryside. 


Nowadays we don’t just want or like tech, we need it! But it isn’t the best for your balls, and may be doing a lot of damage. This is namely phones and laptops and the heat they generate.

Your testicles need to rest at a temperature around 3-5° below body heat for optimal sperm production. Testes hang out of the body in order to regulate their temperature and cool down. But this is a lot more difficult when dealing with extreme temperatures. Phones and laptops generate a lot of heat, and keeping them in your front pocket or resting on your lap for hours on end can be too much for your balls to handle. This heat and close contact can cause your testes to stop producing sperm, and kill the sperm they already have. So keep hot processors far away from your groin!

You can read our article “Testicle Temperature: How Heat Impacts Fertility” to find out more about how heat may be decreasing your sperm quality, and how to avoid it.

What can you do to counteract this trend?

You can do a lot to help out your own sperm. Once you know these everyday things come with a big risk to future fertility, taking steps to avoid some of them isn’t too difficult. You can’t really avoid the environmental impacts on sperm, but you can still improve it in other ways.

The simplest solution? Living healthily. Regular exercise, a healthy diet rich in nutrients, keeping your groin safe from injury and excessive heat. 

You can also keep an eye on your sperm health with an ExSeed home-test kit. The overall decrease in sperm health doesn’t mean every guy’s health is slightly worse than it would’ve been 10 years ago. Some men will have much, much lower sperm parameters. Currently, 1 in 6 heterosexual couples struggle to get pregnant, and around 30-50% of fertility issues are due to male factor infertility. So if you’re looking to have kids now or in the future, the best thing you can do is get your swimmers checked out.

Not only can you test your sperm from home, the free ExSeed app gives you detailed information about your sperm quality and what you can do to improve it. You can access support and advice from specialists to find out what options are available to you and what changes you can make.

Want to know more about protecting our sperm health? Join our FREE webinar on the 3rd November – grab your tickets here. 

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Wearing tight pants and underwear

Studies show that men who wear looser underwear have higher sperm concentration and total sperm count compared to men who wear tighter underwear. So, lose the tight clothes and wear something loose to give your testicles some air.

CONCLUSION: learn more about how heat can affect sperm quality here.


Besides higher mortality rate and various diseases, stress is associated with low sperm quality. Stress is known to be associated with lower testosterone levels and oxidative stress with both playing an essential role in producing and maintaining healthy sperm cells.

CONCLUSION: If you feel stressed, we recommend you get some help so you can have a balanced mental health. For a stress management guide, download the ExSeed app for free and start your personalized action plan today.

Physical activity

Scientific studies show that men who are physically active have better semen parameters than men who are inactive. Fertility specialists also state that regular physical activity has beneficial impact on sperm fertility parameters and such a lifestyle can enhance the fertility status of men.

Prioritizing exercise can help improve your overall health and result in healthy, fast swimming sperm cells that have good chances of fertilizing an egg.

CONCLUSION: Try incorporating exercise in your weekly schedule to you ensure exercising at least twice weekly. We recommend a combination of cardio training and strength exercise. Read more about exercise and male fertility on our blog.


Fast Food
Processed foods damage the health of sperm-producing cells and cause oxidative stress, which lead to poorer sperm quality. Heavy consumption of junk food (every week) can increase the likelihood of infertility since men who consume vast amounts of unhealthy food are at risk of having poor sperm quality. Besides harming your fertility, junk food enlarges your waistline, harms your cardiovascular system, kidneys, and more.

Eating more fruit and vegetables can increase your sperm concentration and motility. It’s important that you consume a healthy diet filled with antioxidants and that you eat vegetables every day. Foods such as apricots and red bell peppers are high in vitamin A, which improves male fertility by nurturing healthier sperm. Men who are deficient in this vitamin tend to have slow and sluggish sperm.

Sugary snacks/beverages: several times a week Excessive consumption of high sugar items can lead to oxidative stress, which negatively impacts testosterone levels and sperm motility. Sugary snacks and beverages are also highly associated with obesity and low fertility.
CONCLUSION: To boost sperm quality, stay away from fast food, processed food, and sugary snacks or beverages. You need to implement a healthy prudent diet filled with necessary superfoods needed for good sperm production. Check out our guide to Male Fertility Superfoods. For personalized guidance and support on how you can start improving your sperm health, check out the Bootcamp.


Direct heat can inhibit optimal sperm production and cause Sperm DNA damage. Sperm cells like environments that are a couple of degrees lower than body temperature. Avoid overheating from warm blankets, seat warmers, heat from your laptop, hot showers, and saunas.

Cigarette smoking

The exposure to tobacco smoke has significant negative effects on semen quality. The damage of cigarettes and nicotine of course depends on how many cigarettes you smoke per day and for how long, but even low usage (up to 10 cigarettes / day) can inhibit healthy sperm production.  

CONCLUSION: Stay as far away from cigarette smoking as possible if you care about your general health and your fertility. Read more here.

Cell phone

When you have your cell phone in your front pocket, your testicles are exposed to electromagnetic radiation, which studies have shown to damage the sperm cells. Put your phone in the back pocket of your pants or in your jacket pocket.


There is a clear association between obesity and reduced sperm quality. At least part of the reason for this is that obese men may have abnormal reproductive hormonal profiles, which can impair sperm production and lead to infertility. 

A BMI higher than 30 can lead to several processes in the body (overheating, increase in oxidative stress in the testes, sperm DNA damage, erectile dysfunction) that can have a negative impact on male fertility. This can result in problems when trying to conceive.  

CONCLUSION: BMI is one of the risk factors that influence semen quality and, for example, sperm motility.  


A beer or glass of wine now and then do not really harm sperm quality. But excess alcohol drinking (more than 20 units per week) can reduce the production of normally formed sperm needed for a successful pregnancy.

CONCLUSION: If you want to stay safe, stay under 14 units of alcohol per week. For more information on how alcohol can affect male fertility, take a look at our blog: “Alcohol and Sperm Quality”.


Studies show that women younger than 35 and men younger than 40 have a better chance of getting pregnant. Men can produce sperm cells almost through their entire life, but the sperm cell DNA is more fragile and prone to damage after the age of 40.

As men age, their testes tend to get smaller and softer resulting in a decline in sperm quality and production. These changes are partly because of an age-related decrease in testosterone level, which plays a very important role in sperm

production. Higher male age (>40 years) is not only associated with a decline in sperm production but also with increased sperm DNA fragmentation and worsened morphology (shape) and motility (movement). These negative effects make the sperm cells less qualified for egg fertilization.

CONCLUSION: with an age under 40, you shouldn’t have to worry much about age as a factor in itself. However, studies have shown a slow decline after the age of 30-35 years

and if you are above 40 years of age, your sperm quality can be affected due to increased sperm DNA damage resulting in a decrease of sperm motility and concentration. Remember that you cannot evaluate the quality of a sperm sample by just looking at it – this requires a sperm analysis.