Few sports are doing enough to protect athletes from brain damage

FANS OF LARGE men colliding with one another are in luck. Next weekend the Six Nations, a rugby contest for the best teams in Europe, gets going in Paris. Two days later the Super Bowl kicks off in Atlanta. Some 115 cameras will beam the final of the National Football League (NFL) to fans around the world, along with advertisements urging viewers to drink beer and eat nachos. It is not a time for healthy living. Yet there is growing awareness that it is not just gluttonous fans who suffer. Contact sports can lead to serious health problems for the players, too.

An occasional broken limb is an accepted, if unfortunate, part of such games. The big worry is about what they do to the brain. In 2017-18 some 291 concussions were reported in the NFL, the highest number since records began six years ago. The same year English rugby union recorded 18 concussions per 1,000 hours of play, almost one a match, and three times as many as five...