A new study on the rising age of television viewers, along with primetime ratings results from this summer’s top cable networks, should cause programmers some concern.

The median age of viewers during the 2013-14 TV season has risen by 2.5 years, to 44, since the 2009-10 TV season, according to MoffettNathanson Research. Further, the

research said, cable viewers have gotten 8% older in the past five years and are now a median age of 40.

Outside of the kids’ networks, the survey said the youngest networks were Nick At Nite (20.8 years), MTV2 (23.2), MTV (23.5) and Adult Swim (23.8). But even all of those networks are

skewing older than they were during the 2009-10 season, according to the report.

Those findings are consistent with viewership for the most-watched cable networks on cable in primetime this summer. Seven of the top 10 networks posted double-digit declines among the younger

18-34 audience during the period of May 26 to Aug. 31, according to Nielsen. Only Fox News Channel and ESPN — both of which had significant live programming events/breaking

news stories during the summer -- posted increases in the demographic.

The top 10 cable networks didn’t fare much better among total viewers, with six out of 10 posting year-to-year declines, but the decline in younger viewers is particularly notable.

While younger viewers are accessing programming on alternative platforms, the numbers show that the migration from traditional TV to other distribution outlets could be accelerating. These are the

consumers cable needs to attract and secure to replace the older viewers as subscribers.