Individual Lifestyle and Male Fertility

Over the past decades there has been a significant decline in the birth rate in many countries raising the question of the role and degree of involvement of biological factors in this process. Up to 30% of couples of reproductive age have fertility problems, and in half of the cases, the cause is due to male factors. However, up to 40% of cases of male infertility are idiopathic, i.e., with unexplained causes. More and more evidence suggests that environmental factors are the causes of growing male infertility and subfertility, among which the individual lifestyle seems to be the most significant. Many researchers believe that lifestyle factors make a significant contribution to the existing negative trend of global decline in the male reproductive potential. The main factors of an individual lifestyle that cause a weakening of male reproductive health are considered to be obesity, unhealthy nutrition, physical inactivity, smoking, excessive alcohol intake, psychological stress, low-level radio-frequency electromagnetic fields (mobile phones and portable computers), aging, and others. Many factors of an individual lifestyle can reduce sperm production, mobility and normal morphology, increase damage to the sperm DNA, and have a negative impact on the endocrine control of reproductive function, which can lead to male subfertility and infertility. In recent years, a significant amount of data has been accumulated that allows us to create an exhaustive and multifaceted picture of the lifestyle effects on the male reproductive function. This review focuses on the negative impact of the most common factors: obesity, diet, sedentary lifestyle, smoking, and alcohol consumption on spermatogenesis and the profile of reproductive hormones in men.