There are pros and cons in the use of cannabis in the medical field. It can treat various physical and mental disabilities, but it can also have an adverse effect on men, especially with their sperm count and its genetic makeup.

Scientists at the Duke University Medical Center in Durham discovered that the use of marijuana not only has consequences in cognitive development and skills but also affects men biologically. In the group's study published in the journal Epigenetics, they revealed that cannabis also affects sperm DNA.

This finding came from experiments carried out on rats and 24 male subjects. The researchers compared the sperm of those who smoke marijuana at least weekly for the previous six months and those who had not used the drug in the past six months but used it not more than ten times in their lifetimes.

The results showed that tetrahydrocannabinol (THC) found in cannabis attacks genes in two metabolic pathways that are responsible for organ growth and growth regulation during development. This ultimately affects the natural regulatory DNA process methylation, which transfers methyl groups to DNA bases that are important for normal development. Suffice to say, THC affects male's reproductive health and changes the genetic makeup of the sperm, says Scott Kollins, Ph.D., senior author of the study and professor in psychiatry and behavioral sciences at Duke.

"We don't yet know what that means, but the fact that more and more young males of child-bearing age have legal access to cannabis is something we should be thinking about."

However, the research did not reveal whether DNA changes triggered by THC are passed on to the user's offspring. The study also did not reveal the effects it could have on the user's children.

Susan K. Murphy, Ph.D., associate professor and chief of the Division of Reproductive Sciences in obstetrics and gynecology at Duke, says the study is inconclusive of what it means to the developing child. The research did not reveal whether sperm affected by THC in cannabis is capable of fertilizing an egg and help it develop into an embryo.

Its effect to sperm structure is not the only adverse effect THC in cannabis has on male's reproductive system. Previous studies reveal that it also lowers testosterone levels among heavy cannabis users, which can negatively influence sperm production. This is why it is advisable to cut back on marijuana use if you plan to start a family.