A study published last summer, conducted by Hebrew University in Jerusalem (Israel) and the Icahn School of Medicine at Mount Sinai in New York (USA), found that the concentration of sperm in western men had halved. There has been a steady decline over the past forty years, to which lifestyles and environmental factors have probably contributed.

With the help of Dr. Luciano Negri, specialist in andrology at the Fertility Center of Humanitas, we find out which factors can affect male fertility.

“First of all, it is important to underline how the early detection of possible disorders is fundamental in preserving fertility, which is why it is advisable to undergo an andrological examination around the age of 18-20, even in the absence of symptoms. The specialist examination, together with the ultrasound of the testicles and the spermogram (which evaluates the sperm in terms of quality and quantity), makes it possible to diagnose any disorders at an early stage and intervene where necessary,” says Dr. Negri.


Overweight and obesity

Conditions such as being overweight and obesity can affect fertility. We therefore need to have a healthy diet, regular physical activity and normal weight; we need to pay attention from an early age in order not to suffer from excess weight or obesity at puberty, when the reproductive system is developing.

“Obesity causes an alteration in hormone levels leading to a reduction in testosterone production (the male hormone) and an increase in estradiol (the female hormone). The excessive weight also causes a constant overheating of the testicles, affecting their regular development”, explained Dr. Negri.


Smoking and Alcohol

Smoking damages spermatozoa, as Dr. Negri points out: “Nicotine and the other toxic substances contained in tobacco, circulating in the blood, reach the seminal fluid and cause a reduction in the number, motility and quality of spermatozoa, as has been highlighted by several scientific studies.

Excess alcohol also damages the spermatozoa, in terms of vitality and motility.


A mobile phone in your pocket

There is a widespread habit of holding the mobile phone in the pockets in front of the trousers, a habit that would be better avoided: “The electromagnetic waves emitted by the phone cause micro-breaks in the DNA of the spermatozoa; this is a damage that, although not irreparable, can decrease the activity of the seminal fluid”. Moreover, be careful when using a laptop, always resting it on your legs.



The intake of “forbidden” substances to enhance sports performance, as well as being dangerous to health in general, also compromises fertility. The use of these products is widespread even among very young people. “Often these products contain testosterone and other hormones such as anabolic steroids, substances that are dangerous to health because they cause severe hormonal imbalances, also putting at risk the health of the reproductive system,” concluded Dr. Negri.