Pro athletes are known to swallow anything that might give them an edge. But one novel substance that’s perfectly legal is helping prolong the career of one of the NBA’s all-time greats.

Who’s the G.O.A.T. — the greatest of all time — in basketball?

Most fans would pick Michael Jordan, and it would be hard to vote against the former Bulls superstar.

But which contemporary player has established the greatest legacy? That would be the man who recently passed up Jordan as the NBA’s third all-time scorer: long-time LA Lakers star Kobe Bryant.

The last two years, however, Bryant has spent most of the season rehabbing some serious injuries, and given the wear and tear of playing nearly 1,500 games over 19 years in the NBA, his return to the court each time has been nothing short of amazing.

His record — and his longevity — is due in large part to an incredible work ethic, but it’s also the result of a “secret ingredient” from an unlikely source: Beef, pork and chicken bones.

That’s right. According to a recent story on ESPN.com, Dr. Cate Shanahan, director of the Lakers PRO Nutrition Program, one of the staples of Bryant’s overall nutritional plan is a chicken-and-vegetable soup made with bone broth. But not ordinary broth. Bone broth, which is made by simmering the bones for hours at a time, is a super-nutritious concoction that contains a slew of nutrients and minerals, including collagen, which is essential for the health of tendons, ligaments and joints.

But does it actually speed up the healing process?

The ESPN story noted that Bryant recently turned his ankle during a game. In fact, he called it “his worst sprain since 2000,” with his injured ankle swelling almost immediately to the size of a tennis ball. Lakers training staff declared that he would be out of action “indefinitely.”

Yet he missed only two games.

“As Bryant creeps toward the two-decade mark in the NBA,” the story continued, “every element of how he prepares, trains and recovers is so much more important, so much more amplified. Including what’s in his soup bowl.”

Bryant has apparently been quietly consuming bone broth for the past three year; no athlete wants to let his competitors in on his training tips. The broth is part of his pregame meals, and the Lakers put in long hours to make sure it’s carefully prepared when the team is on the road, according to the story.

The source of its strength

Bone broth might not be high-profile, but it hasn’t escaped the notice of foodies, if not athletic trainers. A recent article in The New York Times noted that bone broth has evolved from a “prehistoric food to Paleo drink.” In New York City, celebrity chef Marco Canora recently opened a storefront in the East Village where bone broth is served in coffee cups as a health booster.

The bone broth movement in Lakerland began when Shanahan became the team’s consulting nutritionist in 2012. She told ESPN.com she is a “devout believer” in what she called the broth’s “magical” powers, and saw results as she began working with players to improve their diets. Soon after, the team's training staff became believers, as well.

“Everybody is looking for a magical elixir or some cure-all,” said Tim DiFrancesco, the Lakers strength and conditioning coach, “but bone broth is where it’s at.”

The only drawback appears to be the lengths it takes to make the stuff, often up to 24 hours to boil the bones, let them slow-cook with vegetables and seasonings, then let it cool into what’s described as a thick gelatinous substance — due to the collagen that leaches out.

“The way you know you have real stock on your hand is if you put it in the refrigerator overnight and it basically turns into Jell-O,” Shanahan said.

Does bone broth really speed up healing when basketball players suffer sprains, strains and other connective tissue injuries? It’s hard to believe multi-millionaire athletes would bother with anything that didn’t improve their recovery from injuries, the one often career-defining factor that cannot be controlled, no matter how hard they practice.

Since the Lakers play in Los Angeles, I wonder how many vegan and vegetarian fans would approve of Bryant’s bone-broth regimen, if they knew it might make the difference between the team winning or losing? Would they abandon their devotion to the team that’s feeding its star nutrients derived from the slaughter of a sentient creature? Lose their love for a player that as much as any other in the team’s long history has come to define its championship pedigree?

That would be an interesting vote to take on the Fan-O-Gram during a timeout at some future contest.

Pick your poison: Either some cow gets to live and Bryant has to sit, or vice versa.

The opinions expressed in this commentary are solely those of Dan Murphy, a veteran food-industry journalist and commentator.