Um okay, one sec - okay, so polar bears tend to store a ton of Vitamin A in their liver because it helps them deal with the cold environment. Essentially if you're not careful and you eat too close to the liver, you overdose on Vitamin A, which sounds like it might not be that bad but it is. It makes your brain swell, which keeps you from caring when you turn bright yellow and run into things.
Also there's a parasite in lots of polar bear meat that kills people too, but she didn't really go into that.