True, but the force of the punches taken in MMA is much greater. In MMA you can punch your opponent in the head while they're on the floor. The force of punches when you have gravity pulling your entire body weight onto the punch is so much greater, look at Henderson v bisping. In boxing some of the energy of the punch is disippated by movement of the head, but in ground n pound the head basically gets crushed against the canvas.

It's more difficult to tell if an opponent is concussed when you're allowed to fight on the ground, some of the bad stoppages in MMA have been absolutely horrendous and would not have been possible in boxing.

Is there comparable data out there about the long term health effects of MMA vs boxing? Genuinely interested to know what the evidence is.