Dear Dr G,

I read with interest the focus in the last few weeks on female impact on fertility. I guess you did not elaborate on the impact of men and fertility due to overwhelming importance of female factors.

My wife and I have been married for more than a decade; we focused on our careers so that our offspring will have a better quality of life.

Although I often bank on my wife being 10 years younger than me to mitigate the impact of age-related infertility, I still cannot help but wonder about the negative implications of ageing and its effect on a man’s sperm quality.

As I venture into the fourth decade of my life, I hope to embark on the journey of parenthood with my wife this year.

Despite most doctors’ assurance of zero negative impact of my older sperm on the next generation, I still would like to put Dr G on the spot for his opinion.

Firstly, are there any changes in the quality of sperm in ageing men?

If so, what are the changes, and why?

What measures can a man take to improve the quality of his sperm?

Lastly, should I really be concerned with my ageing sperm above 40?

Yours truly,

Ageing Alan

Male fertility has long been considered relatively stable compared to female fertility, which declines more sharply with age.

However, growing scientific evidence shows that advancing paternal age is associated with gradual changes in sperm quality, reproductive outcomes, and potential risks to offspring health.

Research over the past few decades has demonstrated that several key semen parameters decline as men grow older. Studies have reported reductions in semen volume, sperm concentration, motility, and the proportion of normally-shaped sperm.

These changes often begin gradually after the mid-30s and may become more pronounced after the age of 40. Although many older men remain fertile, the probability of impregnation may decrease, and the time required to conceive can increase.

This decline is partly attributed to reduced efficiency of the testes and changes in hormonal regulation, particularly a gradual decrease in testosterone production.

One of the most significant age-related concerns involves the integrity of sperm DNA. As men age, sperm are more likely to exhibit DNA fragmentation and genetic mutations.

These changes are thought to result from cumulative exposure to environmental toxins, oxidative stress, and natural cellular aging processes.

Damage to sperm DNA can reduce fertilisation potential, impair embryo development, and increase the likelihood of miscarriage.

Some research also suggests a link between advanced paternal age and a higher risk of certain genetic or neurodevelopmental conditions in children, although the absolute risk remains relatively low.

Chronic illnesses such as diabetes, hypertension and obesity are associated with hormonal imbalance and increased oxidative stress, both of which can negatively affect sperm production and function.

Environmental exposure, including smoking, excessive alcohol consumption, and contact with pollutants or heat, may also contribute to declining fertility.

Thus, age-related fertility changes often reflect a combination of intrinsic biological factors and modifiable lifestyle influences.

Despite these challenges, there is strong evidence that certain measures can help improve sperm quality and fertility potential in older men. Adopting a balanced and nutrient-rich diet plays a central role in supporting reproductive health.

Nutrients such as zinc, selenium, omega-3 fatty acids, folate and vitamins C and E are particularly important for maintaining sperm motility and protecting DNA integrity.

Maintaining a healthy body weight is also crucial, as excess body fat can disrupt hormonal balance and reduce testosterone levels.

Regular moderate physical activity contributes positively to male fertility by improving cardiovascular health, metabolic function and hormonal regulation.

Exercise enhances blood flow, including to reproductive organs, and may help reduce inflammation and oxidative stress.

However, extremely intense or prolonged endurance training can have the opposite effect by suppressing testosterone and impairing sperm production.

Therefore, balanced exercise routines are generally recommended.

Lifestyle modifications such as quitting smoking, limiting alcohol intake and avoiding recreational drugs can lead to measurable improvements in sperm parameters over time.

These substances are known to impair sperm concentration, motility, and genetic quality.

Similarly, minimising exposure to excessive heat is important, as sperm production requires a temperature slightly lower than core body temperature.

Simple habits such as wearing loose-fitting clothing, avoiding frequent use of hot tubs or saunas, and reducing prolonged sitting can help maintain optimal testicular function.

Sleep quality and stress management also play important roles in reproductive health. Adequate sleep supports hormonal balance and overall cellular repair processes. Psychological well-being and lifestyle stability may therefore indirectly enhance fertility.

Medical evaluation is particularly important for older men who are attempting to conceive. Semen analysis, hormonal testing, and screening for conditions such as varicocele or reproductive tract infections can identify treatable causes of reduced sperm quality.

Management of chronic diseases and appropriate medical or assisted reproductive interventions may significantly improve the likelihood of successful conception.

While male fertility does not decline as abruptly as female fertility, advancing age is associated with measurable reductions in sperm quality and reproductive efficiency.

Biological ageing, increased DNA damage, hormonal changes and lifestyle factors all contribute to this process.

Nevertheless, many of these influences are modifiable. Through healthy nutrition, regular exercise, avoidance of harmful substances, stress reduction and appropriate medical care, older men can improve their reproductive health and enhance their chances of fatherhood.

Understanding these factors allows individuals and healthcare providers to make informed decisions about fertility planning in later life.

Legendary American actor Fred Astaire famously said: “Old age is like everything else. To make a success of it, you’ve got to start young.”

Older men hoping to make a success of parenthood often put Dr G on the spot for an opinion on their ageing sperm. His view is: “If you couldn’t start young, start now!”