Recent research has raised concerns about declining male fertility, with studies indicating that sperm counts have dropped by half over the past 50 years. Condoms UK has partnered with Dr Gareth Nye, a lecturer in biomedical science at the University of Salford and a leading researcher in reproduction, to identify nine common lifestyle habits that may be contributing to this trend. Dr Nye, who also serves as theme lead for endocrinology at the Physiological Society, shared evidence-based insights into how everyday choices could affect sperm health and offered practical advice for protecting reproductive wellbeing.
Processed foods linked to lower sperm counts. Dr Nye highlighted the impact of diet on fertility. “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,” he said. “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 diet high in processed foods, such as ready meals and sugary snacks, may therefore pose a risk to male fertility.
Exercise: finding the right balance. Physical activity is another critical factor. “Regular exercise helps keep blood and oxygen flowing around the body, which is important for healthy sperm,” Dr Nye explained. “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.” Moderate exercise, such as brisk walking or cycling, is recommended to support reproductive health.
Temperature matters for sperm production. The environment around the testicles plays a significant role. “Testicles need to stay cooler than the rest of your body to produce healthy sperm,” Dr Nye said. “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.” Opting for looser clothing and avoiding direct laptop contact can help mitigate these risks.
Alcohol’s impact on testosterone. Excessive drinking is another concern. “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,” Dr Nye noted. “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.” Limiting alcohol consumption is a practical step for those looking to protect their fertility.
Microplastics and hormone disruption. Exposure to bisphenol A (BPA) and microplastics is an emerging issue. “A recent study found that the amount of microplastics in each testicle could make a Lego mini figure,” Dr Nye said. “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.” Reducing exposure to plastics, such as by avoiding plastic food containers, may help.
Smoking and vaping risks. Nicotine, whether from smoking or vaping, poses significant risks. “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,” Dr Nye explained. “This could be harming the fertility of a whole generation. Even vaping without nicotine makes sperm less able to swim to the egg.” Quitting smoking and vaping is strongly advised for those planning to start a family.
Weight loss drugs under scrutiny. The use of Ozempic, a popular weight loss drug, has raised concerns. “The so-called ‘miracle’ weight loss drug has been linked to erectile dysfunction and low testosterone in men who aren’t diabetic,” Dr Nye said. “This suggests it could also affect other parts of the male reproductive system and lower sperm quality.” Men considering such medications should consult a healthcare professional about potential fertility impacts.
Condoms UK, a leading online retailer with over 800 five-star Trustpilot reviews, commissioned this research to raise awareness about male reproductive health. Dr Nye’s findings underscore the importance of making informed lifestyle choices to support fertility in an era of declining sperm counts.
