LONDON, ONT. -- When you think of the risks contact sports could have on the brain, the first thought is concussions. Although, yes, concussions can have life-long impacts, what about athletes who play contact sports but don’t ever sustain a concussion?

“As far as a neurologist or a sports medicine doc, looking at these people, they seem perfectly normal," says Ravi Menon, a professor at the Schulich School of Medicine and Dentistry.

But, Menon says, a closer look using several MRI methods to examine brain function paints a different picture.

As part of a five-year study, the research team followed 101 varsity athletes at Western University, 70 who played rugby and 31 who participated in either rowing or swimming. The idea was to compare the brains of athletes who played contact sports.

“The women who didn’t get concussed were still showing changes in brain structure and function that were quite similar to the concussed ones.” Says Menon.

The study showed 70 percent of the rugby players experienced an average of three impacts over two practices and one pre-season game.

“These repeated impacts tends to damage the larger fiber tracks so these are the highways that connect the left and the right side of the brain.”

Menon says what the brain then does is reroute information on a different path, which is why it appears the athlete is fine, however the concern is over time that this could lead to impacts later in life.

“Then when you do finally one day develop symptoms of Alzheimer’s or let’s say you have a stroke or something, your brain has no new pathways it can exploit and then it becomes very, very critical.”

Now that these findings have been released Menon hopes coaches, parents and athletes are more cautious and aware of the potential affects mild impacts can have over time.