HOT topic. Head injuries are now well publicized in both professional and college sports, and appears that modifications are coming. For we who are not world-class and merely weekend jocks, would urge use of helmets, for biking, skiing, kayaking, horse riding, etc. If around loud noises use ear plugs or head phone protection. You can't avoid all risks, but above prudent approach may minimize.
Avoid contact. Most brain or head trauma is from contact of one type or another. Direct hits from other bodies, from a ball, bat, or other object. Head protection can minimize this, but experience from football still shows traumatic events. The best course is to avoid the possibility of trauma before the event.
Protect head. If you use either hard hats or helmets during work that is hazardous or atheletic activity that creates head injuries this can prevent damage to brain, dont drink and drive, wear seat belts while drinving, if there is a problem with balancing use soft foam helmets at home.