UPDATE 2-NFL players union funds $100 mln Harvard study on injury

(Adds NFL response, paragraphs 11-12) BOSTON, Jan 29 (Reuters) – The union that represents U.S. professional football players has given Harvard University a $100 million grant for a study of the range of health problems, from brain damage to heart conditions, that affect current and former players. Researchers with Harvard Medical School plan to spend a decade studying hundreds of former players who are members of the National Football League Players Association, university officials said on Tuesday. …