The NFL's political action committee has given nearly $300,000 in campaign contributions to 41 of 54 members of a key congressional committee that is reviewing concussion research.

Analysis of campaign finance data since 2008 has found the NFL's Gridiron PAC has supported members of the U.S. House Energy and Commerce Committee that began informal hearings last week on one of the league's most pressing safety issues.

Michigan Republican Fred Upton, the committee chair, announced in December lawmakers would conduct a broad review of concussion research this year.