I think all in all it's okay to teach kids this age a contact sport. The risk of injury here is probably less than football because they are trained and more disciplined. I certainly hope the rules are a little more strict as far as head strikes go. There is definite potential for lethal consequences.
The statements contained herein have not been evaluated by the Food and Drug Administration. The consumer comments and experiences relayed herein may not be typical. Your experience may vary.
Disclaimer: The advice I provide is based on experience and/or research and should not be considered professional medical advice. It is best to confirm any potential use of a drug or possible medical condition with a licensed doctor.