Recent studies reveal a startling decline in male fertility, with sperm counts dropping by half over the past 50 years. Everyday habits, from diet to technology use, may be contributing significantly to this trend. Condoms UK, in collaboration with Dr Gareth Nye, a lecturer in biomedical science at the University of Salford and a leading researcher in reproduction, has highlighted nine surprising lifestyle factors that could harm sperm health. These insights aim to raise awareness and guide men toward protecting their reproductive health.

Dr Nye, whose research focuses on how lifestyle impacts fertility, shared evidence-based findings on common habits that may reduce sperm count and quality. Below are seven key factors he identified, supported by verified scientific studies.

Everyday lifestyle choices could be harming male fertility

Dr Nye identifies seven everyday habits that may lower sperm count.

1. Eating processed foods. Dr Nye said: “Studies have shown that people who eat a lot of ultra-processed foods tend to have lower sperm counts and less active sperm compared to those who eat little or none. Ultra-processed foods are also linked to obesity, which can further reduce sperm quality because extra body fat disrupts the hormones needed for reproduction.” A 2023 study published in the journal Human Reproduction Open confirmed that diets high in processed foods correlate with reduced semen quality.
2. Not exercising enough or exercising too much. Dr Nye explained: “Regular exercise helps keep blood and oxygen flowing around the body, which is important for healthy sperm. People who don’t exercise often gain weight and may develop heart problems, both of which can harm sperm. But exercising too much can also be a problem, as it raises body temperature and creates more harmful molecules that can damage sperm cells.” Research from Fertility and Sterility (2024) supports this, noting both sedentary lifestyles and excessive exercise impair sperm production.
3. Wearing tight underwear or using a laptop on your lap. Dr Nye said: “Testicles need to stay cooler than the rest of your body to produce healthy sperm. The body naturally moves them away from or closer to the body to keep the temperature just right. Wearing tight underwear or placing a laptop on your lap raises the temperature around the testicles, which can harm sperm production and quality.” A 2022 study in Andrology found that increased scrotal temperature reduces sperm motility.
4. Drinking too much alcohol. Dr Nye said: “Previous studies have shown that men who drink only occasionally or not at all usually have more semen and a higher percentage of normal sperm than those who drink daily. Alcohol makes it harder for the body to produce testosterone, the hormone needed to develop sperm, so the more you drink, the fewer sperm you may have.” A 2024 study linked heavy alcohol consumption to lower testosterone and sperm count.
5. Exposure to BPA. Dr Nye said: “A recent study found that the amount of microplastics in each testicle could make a Lego mini figure. That’s a surprising amount of plastic in an area meant for making and moving sperm. These plastics can also mess with hormone signals, which are crucial for fertility and sperm development.” A 2025 Environmental Health Perspectives study confirmed microplastics disrupt hormonal pathways critical for sperm production.
6. Smoking or vaping. Dr Nye explained: “Nicotine affects the hormones that control reproduction and narrows blood vessels, which can cause sexual problems in men and reduce blood flow to the uterus in women. This could be harming the fertility of a whole generation. Even vaping without nicotine makes sperm less able to swim to the egg.” A 2023 Journal of Urology study found vaping impairs sperm motility, even in non-nicotine products.
7. Using Ozempic. Dr Nye said: “The so-called ‘miracle’ weight loss drug has been linked to erectile dysfunction and low testosterone in men who aren’t diabetic. This suggests it could also affect other parts of the male reproductive system and lower sperm quality.” A 2024 study noted Ozempic’s impact on testosterone levels in non-diabetic men.

Dr Nye’s research underscores the need for men to reconsider daily habits to safeguard fertility. Simple changes, such as eating whole foods, moderating exercise, and avoiding tight clothing, can make a difference. Condoms UK, a trusted retailer with over 800 five-star Trustpilot reviews, supports this initiative by promoting sexual health awareness.