The Dallas Cowboys and New York Giants kick-started this year’s National Football League season Wednesday in East Rutherford, NJ. By all accounts, it was a lovely evening.

Queen Latifah belted out an inspired rendition of “The Star Spangled Banner.” As she concluded, military helicopters flew overhead, delighting the 82,000 fans in attendance — and millions more watching at home. That was followed by a quick TV shot of NFL Commissioner Roger Goodell, who had good reason to be smiling. He is presiding over the office at a time of record crowds, television ratings and profits.

Football has become our national sport. This wonderful, tough game has been turning boys into men for generations. But it may also be turning men into nursing home residents way before their time.

Just hours before the game began, a study was released that suggests that professional football players are three times more likely to face neurodegenerative diseases. For Alzheimer’s disease and ALS — amyotrophic lateral sclerosis, also known as Lou Gehrig’s disease — the risk for football players is four times higher.

The study, appearing in the medical journal Neurology, surveyed almost 3,500 former NFL players who were in the league between 1959 and 1988. Authors also examined the neurological outcomes of the players by evaluating the autopsies of 334 players.

Investigators found that among the deceased players, seven had died from Alzheimer’s and another seven had ALS. The average age of the players who had died was 57.

These latest findings come in the wake of previous studies showing that football players are also more prone to concussions.

As a fan of the game, I find these kinds of results heartbreaking. Football is a great sport. But it is also violent. And until recently, the full cost of that violence has remained largely hidden. It is becoming increasingly obvious that the human body is not designed to endure the chronic and acute abuse that tackle football dishes out.

Of course, that doesn’t mean most players will give up the sport. The Surgeon General has been pasting warnings about the dangers of cigarettes on the side of packs since the 1960s. And millions of people still light up every day.

Ed Bruce wrote a great country song entitled “Mamas, don’t let your babies grow up to be cowboys” that Willie Nelson made famous.

These days, smart mamas aren’t letting their babies become Cowboys, or Redskins, or Bears or Colts. But there are still plenty of others who believe the rewards of the game are worth the price their babies might have to pay later on.