"Our data showed that men under more stress than the average male population had a lower sperm count in their seminal fluid. The men under most stress had more than 30% fewer sperm cells than men with an average stress level," said Niels Jørgensen, consultant physician and senior researcher, who in collaboration with Dr. Loa Nordkap is behind the study. He continued:
"The results suggest that stress can be a contributory factor in low fertility."
The group of men who themselves felt they were under stress made up a fifth of the 1,215 men studied.
Multiple causes of impaired semen quality
Impaired semen quality is widespread among otherwise healthy Danish men. The causes can be many. For example poor semen quality can be caused already in the foetus by in-utero influences, such as exposure to endocrine disruptors or the smoking habits of the mother during pregnancy.
"Damage caused in the womb cannot be undone in the adult man. It is a different story if the impaired semen quality is caused by stress," said Niels Jørgensen and he continued:
"The positive side to our findings is that individuals suffering from stress and with impaired semen quality can take action themselves. They can try to avoid the stress condition and thereby improve their semen quality.
Future studies will determine whether changing stress levels can actually improve semen quality. Furthermore, the scientists at Rigshospitalet will research further into the basic biological mechanisms behind the link ascertained in the study."
The study has been published in the prestigious scientific journal; Fertility and Sterility.
The connection between genetics, lifestyle and environment in growth and reproduction is the focus of the annual Global Excellence Symposium at Rigshospitalet on 11 November, when Danish and international experts will present new findings in the field.
About the Department of Growth and Reproduction
The Department of Growth and Reproduction is a part of the Juliane Marie Centre at Rigshospitalet. The department treats patients with growth-related problems, puberty-related disorders, male fertility and rare hormonal disorders. The department collaborates closely with scientists from Denmark as well as other countries on research projects directly connected to the diseases and conditions treated in the outpatient department. The Department of Growth and Reproduction received the Centre of Global Excellence in Health in the Capital Region of Denmark award in both 2010 and 2014.
EDMaRC is an international research and teaching centre in male reproduction. The centre is located at the Department of Growth and Reproduction at Rigshospitalet and is also affiliated with the University of Copenhagen.