Infertility is one of the most serious social problems facing advanced nations. In general, approximate half of all cases of infertility are caused by factors related to the male partner. To date, various treatments have been developed for male infertility and are steadily producing results. However, there is no effective treatment for patients with nonobstructive azoospermia, in which there is an absence of mature sperm in the testes. Although evidence suggests that many patients with male infertility have a genetic predisposition to the condition, the cause has not been elucidated in the vast majority of cases. This paper discusses the environmental factors considered likely to be involved in male infertility and the genes that have been clearly shown to be involved in male infertility in humans, including our recent finding. It specifically focuses on zinc and its importance in male fertility.
Sperm, which holds the male DNA, must be able to move back and forth and propel itself to penetrate the female egg. Fertile males have healthy sperm that swim well, but males with impaired fertility may have a lower sperm count, or sperm that do not swim as well. Zinc may play a role in the development and overall quality and quantity of sperm.
Zinc has antioxidative properties and plays an important role in scavenging reactive oxygen species. We hypothesized that in the absence of Zn, the possibility of increased oxidative damage exists that would contribute to poor sperm quality. Therefore, measurement of seminal Zn in the seminal plasma of males with a history of subfertility or idiopathic infertility is necessary and can be helpful in fertility assessment.
The mineral zinc is naturally present in certain foods, and it is added to other foods. The National Institutes of Health notes that zinc is involved in immune function, wound healing, protein synthesis, DNA synthesis and cell division. Zinc is the second most common trace mineral in the body, behind iron, and is present in every cell in the body. Males 14 years and up need 11 milligrams of zinc per day – an amount easily obtained through a healthy diet plus a multivitamin.
Zinc may play an important role in the development of sperm, also known as spermatogenesis. A 2009 a study published on the Proceedings of the National Academy of Sciences website found that the concentration of zinc in the testes increases during spermatogenesis. The study also found that zinc deficiencies reduced sperm motility. The study concluded that zinc is a vital mineral in the development of sperm and the regulation of sperm motility. Still, the extent of zinc’s role in spermatogenesis is not fully understood.
A 2009 study published in “Nutrition Research” hypothesized that due to zinc’s important antioxidant role, a deficiency would increase oxidative damage and promote lower quality sperm. The study found that seminal zinc, in both fertile and infertile males, correlated significant with sperm count. The conclusion was that zinc deficiency is, in fact, a risk factor for low sperm quality and male infertility, for which there is no other apparent cause.
A 2002 study published in “Fertility and Sterility” tested the effects of zinc plus the vitamin folate on fertility-impaired males. The study found that while zinc and folate, each on their own, did not improve sperm count, when combined, the two supplements significantly improved sperm count, as well as the percentage of healthy sperm, in fertility-impaired males. Another study published in the “International Journal of Andrology” also found benefits in combining zinc and folate on fertility-impaired males.
In conclusion zinc is an important element required for healthy sperms and male fertility.
Dr. Sharmila Majumdar