Caffeine in moderate doses stimulates the formation of spermatozoids

José Pichel Andrés/DICYT A study indicates that caffeine can influence spermatogenesis, the formation of male gametes or spermatozoids. The study, which has been carried out by the Universidad de Beira Interior and recently published in the scientific journal Toxicology, indicates that caffeine in low or moderate doses stimulates this process, while in high doses it could be harmful.

“The results show that caffeine alters the metabolism of the Sertoli cells, which encourage the development of spermatozoids”, Pedro Oliveira, a researcher at the Universidad de Beira Interior, explains to DiCYT. In low or moderate doses the compound stimulates these cells to produce lactate, an essential metabolite if spermatogenesis is to occur. However, when the amount of caffeine is very high the opposite effect may occur owing to greater cell oxidation.

In short, “although further study is necessary to clarify the doses of caffeine that may be beneficial or harmful for the functioning of the Sertoli cells, the results suggest that moderate consumption is safe for male reproductive health and encourages conditions for the development and survival of spermatozoids”.

The study was carried out in vitro with human Sertoli cells from testicular biopsies. The researchers applied to these cells three different doses of caffeine to reproduce the concentrations observed in sporadic, moderate, and compulsive consumers of beverages rich in caffeine such as coffee, green tea, and black tea. The scientists believe that these experiments are a good model for understanding what actually happens in the body, taking into account that Sertoli cells are essential to male fertility as they determine the number of spermatozoids that form.

The researchers consider this study to be particularly interesting given the trend in consuming energy drinks rich in caffeine by young people of reproductive age.

Specific undetermined consumption

However, this is “a preliminary study that does not allow the establishing of the specific doses of caffeine that an adult should consume”, Pedro Oliveira warns. In any case, “the results obtained suggest that the ingestion of a daily dose of caffeine corresponding to the consumption of three or four cups of coffee or five or six cups of tea for days seems to have no negative effects on the Sertoli cells” and even “seems to encourage the metabolic operation of these cells”.

However, it should be taken into account that some other foods and beverages also contain a significant dose of caffeine, such as cocoa and some colas, and that the results also indicate that in high doses this compound interferes with cell functioning, which leads to the deterioration of male fertility. For this reason, the scientists think that it is necessary to continue to study the effects of other doses of caffeine.

“Infertility is affecting more and more couples of reproductive age”, the specialist points out. The masculine factor, either in isolation or in combination with the feminine factor, represents two thirds of cases of infertility and is generally associated with metabolic diseases such as obesity or diabetes, together with the consumption of drugs, alcohol, tobacco, and certain medicines. Because of this, “it is essential to study the underlying mechanisms of male reproductive health changes in more detail”.

	Bibliographical reference
	Dose-dependent effects of caffeine in human Sertoli cells metabolism and oxidative profile: Relevance for male fertility. Tânia R. Dias, Marco G. Alves, Raquel L. Bernardino, Ana D. Martins, Ana C. Moreira, Joaquina Silva, Alberto Barros, Mário Sousa, Branca M. Silva, Pedro F. Oliveira. Toxicology, Volume 328, 3 February 2015, Pages 12–20. doi:10.1016/j.tox.2014.12.003