In a column headlined “First, the bad news,” John Stossel explains why it’s a bad idea to base your viewpoints and decisions on media reports.

We in the media rarely lie to you.

But that leaves plenty of room to take things wildly out of context.

That’s where most big scare stories come from, like recent headlines about GM foods. GM means “genetically modified,” which means scientists add genes, altering the plant’s DNA, in this case to make the crop resistant to pests.

Last week, Poland joined seven other European countries in banning cultivation of GM foods.

The politicians acted because headlines screamed about how GM foods caused huge tumors in rats. The pictures of the rats are scary. Some have tumors the size of tennis balls.

What the headlines don’t tell you, though, is that the female Sprague-Dawley rats used in the test usually develop tumors — 87 to 96 percent of the time.

It’s a similar story with chemicals that the media constantly tell us to fear.

More often than not, rats get tumors if given high enough doses of manmade chemicals. I shouldn’t say “manmade.” Nature’s chemicals cause tumors at the same rate.

Reporters and environmental activists have incentives to leave out details that might make the story boring. It’s useful if you think you’re in danger.