Male fertility is a key element in reproduction. Although the focus has traditionally been on female fertility and its determinants, men play an equally important role in achieving a successful pregnancy. Below, we will look at all the factors that play a role and should be taken into account.
Many factors can alter male fertility. Either positively or negatively. Age, habits and lifestyle, supplementation and diet… All these components determine a man’s reproductive health. Let’s resolve these issues.
At what age does male fertility decline?
You may have wondered at what age fertility decreases in men. Recent studies have found that sperm quality begins to decline after the age of 40 (1). Auger’s study reported a 0.6% decrease in the percentage of motile sperm for each year of age. This would translate into a 12% decrease in motility comparing a 50-year-old man with a 30-year-old man (2).
From this age onwards, the probability of genetic mutation increases dramatically. In fact, children of older parents have a higher risk of disorders such as autism and schizophrenia (1). This research confirms the enormous influence of age on male fertility.
Changes in the prostate occur with ageing, such as smooth muscle atrophy and a decrease in citric acid and protein and water content, which affect semen volume and sperm motility (2).
How to improve male fertility after the age of 40?
Although it is true that we all have a biological clock that determines how long we have the capacity to conceive, there are a series of conditioning factors that, if applied, help to delay it. Reducing the consumption of alcohol, recreational drugs and tobacco as much as possible, maintaining a healthy weight, getting enough sleep to ensure a good night’s rest, leading a healthy lifestyle and taking care of your diet can help improve fertility after the age of 40.
What habits affect male fertility?
Maintaining good habits and lifestyle positively affects many aspects of the human being. However, bad habits such as smoking and alcohol consumption have a direct impact on reproductive health. We will see below how they affect reproductive health.
Tobacco:
Reactive oxygen species or ROS are a collection of free radicals and derivatives. They are called all reactive oxygen species (ROS), which are by-products of cellular respiration and are necessary for certain cellular activities (3).
Men who smoke inhale a number of toxic substances as ROS that can be absorbed, so a causal relationship is suspected. Recently, studies have shown that cigarette smoking can lead to increased seminal ROS by several mechanisms: cigarette smoking itself contains high levels of ROS and metabolites that can induce an inflammatory reaction in the male genital tract with a subsequent release of the chemical mediation of inflammation that can recruit and activate leukocytes. Activated leukocytes can generate high levels of ROS in semen, and toxic metabolites from cigarette smoke can impair spermatogenesis, resulting in the production of abnormal spermatozoa, which is a major source of ROS and oxidative stress (5). This would also result in a decrease in sperm quality.
Alcohol:
Alcohol consumption is closely associated with smoking. For this reason, their possible effect on semen quality and male fertility must be taken into account and studied together rather than in isolation (6). The effects of tobacco and alcohol are very similar.
What supplements benefit fertility?
Diet is one of the main environmental factors influencing embryo and foetal development, as well as parental health (3). Specifically, micronutrient deficiencies are significantly associated with high reproductive risk, ranging from infertility to structural defects in the foetus and long-term disease (4).
Let’s look at which minerals, through supplementation, can benefit reproductive health.
Several studies have assessed zinc supplementation and improvements in male fertility.
Antioxidants constantly inactivate ROS, and in our body this is achieved in three ways: through endogenous antioxidants (coenzyme Q-10, uric acid), dietary antioxidants (vitamins C and E, carotenoids, flavonoids) and metal-binding proteins (albumin, transferrin, ferritin, etc.).
This study therefore concludes that the use of antioxidant compounds based on vitamins and trace elements improves the motile sperm count (MSC). This may be a determining factor in determining which assisted reproduction technique is most beneficial for the couple (6).
Aspects of a man’s diet can have an impact on his fertility such as consuming a diet rich in carbohydrates, fibre, folate and lycopene, as well as fruit and vegetable consumption correlates with improved semen quality. Of great importance are also antioxidants, which help to remove excess ROS in the seminal ejaculate and assist in the conversion of ROS into compounds that are less harmful to cells (7).
What tests are available to assess fertility in men?
It is likely that after reading this article, the following question has arisen in your mind: how can I know if I am fertile? The answer is simple, through specialised tests that analyse the quantity, quality and functionality of the sperm and the fertility of the individual.
- Spermiogram (Semen analysis)
This is the main test to evaluate male fertility. It analyses sperm volume, concentration, motility, morphology and vitality. It also examines the viscosity and pH of the semen. - Sperm DNA fragmentation
Measures the degree of damage to the genetic material of spermatozoa, which can affect fertilisation and embryo development. - Sperm capacitation test
Assesses the ability of sperm to swim and fertilise the egg. It is useful for assisted reproductive techniques. - Hormone profile
Measures key hormones such as testosterone, FSH, LH and prolactin, which regulate sperm production and testicular function. - Testicular ultrasound
Allows detection of structural abnormalities in the testicles, epididymis or vas deferens, such as varicocele or cysts. - Testicular biopsy
Performed when there is azoospermia (absence of sperm in the semen) to evaluate if there is production in the testicles. - Karyotyping and genetic studies
They detect chromosomal alterations and genetic mutations associated with male infertility, such as Klinefelter’s syndrome or microdeletions in the Y chromosome.
bibliography
(1) Hammarberg, K. (2024, 21 August). *Men also have a biological clock: these are the problems of having an older father. El País. Retrieved from https://elpais.com/salud-y-bienestar/2024-08-21/los-hombres-tambien-tienen-reloj-biologico-estos-son-los-problemas-derivados-de-tener-un-padre-mayor.html
(2) Balitán Amoretty, C. B., Blanco Knotek, S. A., & Hernández, Y. A. (2018). Factors associated with low sperm quality in students of the Faculty of Medical Sciences of UNAN-Managua in 2017. National Autonomous University of Nicaragua, Managua. Retrieved from https://repositorio.unan.edu.ni/id/eprint/11164/1/99194.pdf
(3) Giraldo Villagrá, A. (2017). Male fertility, zinc and fatty acids. [Final degree thesis, University of Valladolid]. UVaDOC. Retrieved from https://uvadoc.uva.es/bitstream/handle/10324/24987/TFG-M-N1004.pdf
(4) Cetin I, Berti C, Calabrese S. Role of micronutrients in the periconceptional period. Hum Reprod Update. 2010 Jan 1;16(1):80-95.
(5) Colagar AH, Marzony ET, Chaichi MJ. Zinc levels in seminal plasma are associated with sperm quality in fertile and infertile men. Nutr Res. 2009 Feb;29(2):82-8.
(6) Blanco JM, Cabo González JA. Evaluation of an antioxidant compound on seminal parameters of sperm concentration, motility and morphology in patients with idiopathic oligoasthenoteratozoospermia. Rev Int Andrology. 2011 Jul;9(3):109-15.
(7) Sharma R, Biedenharn KR, Fedor JM, Agarwal A. Lifestyle factors and reproductive health: taking control of your fertility. Reprod Biol Endocrinol. 2013 Jul 16;11:66.
