newsflash

A brief media report of something that has recently taken place.

Television programmes were interrupted by a newsflash announcing that the Prime Minister had resigned.

Introduces an obvious fact of which the person addressed is ostensibly not aware.

In the 1980s we thought that fat was the root of all evil, but now people are saying that insulin is what is making us fat or that we should eat paleo, like our prehistoric friends (um, newsflash: most people in the Paleolithic era died from starvation).