The sperm of men who smoke has a greater extent of DNA damage than that of non-smokers, says a new study that points to harmful effects of smoking on male fertility.
Male infertility accounts for about 30 to 50 percent of all infertility cases, and infertile men tend to have high levels of damage to the sperm DNA.
"More and more studies are demonstrating a harmful effect of smoking on male fertility,” senior author of the study Ricardo Pimenta Bertolla from Sao Paulo Federal University in Brazil.
"Our results point in the direction of important semen alterations: Semen of smokers presents an inflammatory nature, associated with decreased capacity of sperm to achieve fertilisation and generate a healthy pregnancy," Pimenta Bertolla noted.
Researchers also assessed 422 proteins in participants' sperm. One protein was absent, 27 proteins were under-represented, and 6 proteins were over-represented in smokers. Analyses of these proteins suggest that cigarette smoking may promote an inflammatory response in the male reproductive tract. The study published in the journal BJU International included 20 non-smoking men and 20 men who smoked.
"More and more studies are demonstrating a harmful effect of smoking on male fertility," said Dr Ricardo Pimenta Bertolla, senior author of the study.