Male fertility and reproductive system is based on 3 stages. (1) A signal from the pituitary gland and gonadotropic hormones to create spermatogenesis. (2) The maturation of spermatozoa within the male reproductive tract. (3) And finally the quality and quantity of spermatozoa.
If we are to look at the first stage of fertility, creation of sperm (spermatogenesis), there are certain exogenous factors that inhibit this process. Alcohol has been shown to impact this by suppressing the hypothalamic-pituitary-testis (HPT) axis having direct toxic effects on sperm cells. Smoking tobacco is shown to have a negative effect on spermatogenesis compared to non-smokers. Fertile men presenting for vasectomy and military physical evaluations who smoke have a decrease in sperm count. Illicit drug use, generally at its highest during puberty, a vital time for testicular development may also be vulnerable to abnormal development of the testes. Drugs that are associated with infertility include anabolic steroids, opioid narcotics, cocaine, methamphetamines and marijuana.
From a nutritional point of view there are certain micronutrients in the diet that promote spermatogenesis and sperm count. Zinc is important for many biological processes and is high in the reproductive tract, especially the testes and prostate. This important divalent metal has been found to increase sperm concentrations and reduce oxidative stress. Selenium is a cofactor for glutathione which is a major antioxidant, therefore vital in protection from oxidative stress. It highest levels are found in the testes, followed by the seminal vesicles. Selenium concentrations in the seminal fluid are positively correlated with sperm concentrations. Iron is a cofactor for many metalloenzymes including one’s involved in spermatogenesis. This being said it is important for iron homeostasis. Iron overload impairs spermatogenesis, as well as iron deficiency. Non-metal micronutrients are also particularly important including boron, folate, coenzyme Q10, omega-3 and antioxidants.
Certain environmental factors like heat and radiation play an important part. Spermatogenesis requires 2-4 degrees Celsius below core body temperature. Increased temperatures can cause cell death and DNA damage. High levels of radiation is a well-known cause of impaired spermatogenesis. Random DNA mutations are increased with elevated levels.
To sum it all up, lifestyle, dietary, environmental and even occupational exposures have a profound impact on spermatogenesis with interest continuing to grow. For further information or to speak with one of our Clinical Nutrition or Naturopathy Student Practitioners about this issue, book online for an appointment or call 1300 859 785.
References:
Gabrielsen, J. S., & Tanrikut, C. (2016). Chronic exposures and male fertility: the impacts of environment, diet, and drug use on spermatogenesis. Andrology, 4(4), 648–661. http://doi.org/10.1111/andr.12198
Ong, C.-N., Shen, H.-M., & Chia, S.-E. (2002). Biomarkers for male reproductive health hazards: are they available? Toxicology Letters, 134(1–3), 17–30. http://doi.org/10.1016/S0378-4274(02)00159-5