Gunnar Andersson, MD, PhD, is an orthopedist at Rush University Medical Center in Chicago who specializes in back pain and injuries. He’s written 250 academic papers and more than 150 books and book chapters on the topic. He says this is a well-done study that it is interesting because it contradicts previous studies that have shown body weight and the type of job you do have an effect on the development of disc degeneration.

“It’s not like this is the definitive study on the subject, but it is an important study because it points out the importance of the genes,” Dr. Andersson says. “I think the problem in the past has been that people have viewed disc degeneration as being specifically caused by work or caused by body weight and other factors. The reality is while all of those are probably important, it seems that the genetic factors are even more important. And so, whether or not you are going to have disc degeneration depends to a larger degree on your gene pool than on what you do.”

He says the downsides of this study are that it followed a small group of participants and they’re all male. It also only looked at L1-L4 discs.

“So I think what we have to do is be a little bit careful about how to interpret it,” he says.

But the research team says they hope their findings reassure patients who have been afraid to regularly lift things.

“If you have back pain, I would say don’t be afraid of moderate activity and some mild to moderate lifting," Battié says. “Don’t go out of your way to exacerbate those symptoms. But if we are talking about people who might be afraid they are damaging the underlying structure of their spine, the disc, thru routine lifting you probably don’t have to worry about that.”

The study was published in the January 2010 issue of The Spine Journal. Next the research team plans to use the study group of twins to look at the effects of different loading conditions not just on disc degeneration, but also on pain.