event sponsored by Saga Cruises? ;p
I've fought guys from 16 to 49 and they were all equally as capable, so I think age is irrelevant, and to be honest to even suggest age classifications is a bit discriminatory IMO. Saying that the toughest guys I've fought have been in their early 20's, but end of the day it's down to experience and how hard people train. More you train the better you are. Simple.
No it's not discriminatory, it's showing a duty of care. There can be no doubt that there are many over 40's that are just as if not more fit than younger fighters but it is important to keep a check on this. We all need health checks as we advance in years. I speak as a 45 year old who has been in the fight game for almost 25 years, am still in reasonable shape but do understand the need for monitoring.
As for a lower age limit. No head contact for under 18's - thats it. It's all very well saying that other sports do this but to pick a few at random - Thai Boxing is constantly under scrutiny because it does not have it's system together across the board and is still allowing under 18's to fight without headguard and in some cases under full rules (lets not get into the headguard debate please - in terms of acceptability all contact sports should be exercising a duty of care and be aware of the percieved view from the public perceptive).
Amateur Boxing and in some cases Kickboxing have head contact with Headguards but the officials make good use of the standing 8 count and only allow the minimum punishment.
I don't know how that could happen in such an explosive sport as MMA if you were to allow head contact with under 18's