Researchers say fast roller coaster rides won't cause brain injuries.

Scientists at the University of Pennsylvania say new amusement rides don't produce a force large enough to harm the brain. Their findings are published in the October issue of the Journal of Neurotrauma.

"We should step back and separate the facts from the hype," said Douglas Smith of the Head Injury Center at the university and co-author of the report.

Brain scan
Brain scan

"No peer-reviewed studies have definitively linked brain injury in healthy individuals to riding the latest and most powerful roller coasters."

Concerns about the effect of the rides on people has led New Jersey to enact legislation to limit G forces on rides.

G force is a way of measuring acceleration. A G force of one is the normal force of gravity on the body. A G force of 4 is the equivalent of the maximum force experienced by astronauts at launch and re-entry.

A report published in January 2002 called for limits on amusement rides.The study said the competition for higher, faster roller coasters may be resulting in more dangerous rides that can cause serious injury or death. Some rides exert a G force of 6.5.

The authors said the rate of injuries and deaths has been climbing over the years. Reported injuries from thrill rides mentioned in the study include swelling and bleeding in the brain, hemorrhaging, blood clots and stroke.

But the Pennsylvania study says the risk of G force is exaggerated. A person has to sustain a G force of 5 to 9 for about 43 seconds before there is any effect. Smith's report says G manoeuvres on roller coasters rarely last more than three seconds.

Researchers examined data from the most popular and powerful roller coasters in the U.S.:

  • the "Rock 'n' Roller Coaster" at Disney in Orlando, Florida
  • "Speed - the Ride" coaster in Las Vegas
  • "Face-off" at Kings Island, Ohio

Researchers calculated the peak accelerations in three directions. They found that even with the worst-case scenarios, the largest forces experienced were far below those known to cause injury.

"What we should be concerned about (is) the effects of rapid head acceleration — the rotational force on the brain that occurs as the body quickly changes direction," said co-author David Meaney. Meaney says the twists and turns on roller coasters are within safety margins.

"It does not appear that roller coasters produce high enough forces to mechanically deform and injure the brain."

Smith and Meaney point out some reports of amusement park trauma can be attributed to pre-existing brain injuries. They also say hypertension can play a role in causing brain trauma.

"For healthy people who meet the size requirements for the ride, you are probably safer on the average roller coaster than driving to the amusement park," said Smith.