A University of NSW study could bury claims that bike helmets do not help.

The research showed helmets reduced fatal head injuries by about 65 per cent.

The study was presented to an injury prevention conference in Finland this week.

“We collected data from 40 different studies using data from over 64,000 injured cyclists,” he said.

“We found that helmet use was associated with about a 50 per cent reduction in head injuries of any severity, about a 70 per cent reduction in serious head injuries and those are usually skull fractures and inter-cranial injury or bleeding in the brain.”

Dr Olivier said some deny the association between helmet use and neck injuries.

“Most specialists, we've known for a long time that bicycle helmets are effective. Usually the arguments against come from groups that are on the fringe.”

Australia is one of just a few countries in the world with mandatory helmet laws, which have seen a significant reduction in head injuries since their introduction.

But the Australian Government still does not enforce helmet wearing for adults, with many saying mandatory helmet laws would stop adults from cycling.

Dr Olivier denies that claim.

“We published a study right before this one in the Medical Journal of Australia where we looked back at some really good high-quality studies ... before and after helmet laws, and we found there was no change in the number of people cycling,” he said.