Cape Town - Men considering fatherhood should steer clear of nicotine – and not only cigarettes but nicotine-replacement products, such as gum or patches, should be avoided.

This is according to University of Stellenbosch research that has found nicotine affects sperm viability.

The preliminary results of the new study were presented at a conference of the Physiology Society of SA at Stellenbosch University yesterday.

“We looked at the effects of nicotine on the male reproductive system,” said the study leader Johann Maartens, a post-graduate student in the university’s department of biomedical sciences.

The two-pronged study tested the effects of nicotine on sperm in a laboratory setting (in vitro), as well as in the human body (in vivo).

The laboratory study found that, in humans and in rats, exposure to nicotine decreased the overall viability of sperm by between 5 and 15 percent.

The sperm quality was assessed by testing the sperm cells’ ability to swim (motility), the amount of live and dead cells (viability), the cells’ ability to fuse with the female egg (acrosome capacitation status) as well as DNA fragmentation (a process associated with cell suicide).

“We don’t know exactly why nicotine is bad for the male reproductive system, but we suspect it is due to the production of free radicals, particularly reactive oxygen species (a specific type of free radical),” explained Maartens.

“We think nicotine causes higher levels of reactive oxygen species to be produced which in turn harms tissue.”

Low levels of reactive oxygen species occur naturally in the body and are observed in certain bodily processes, but increased levels lead to oxidative stress, which is harmful to the body. - Cape Times