I know it's not the height of scientific data, but the Wikipedia on Cave Bears seems to imply the jury is still out on that topic - they definitely have eaten one another... So that's some instances of bear cannibalism and there's possible evidence of eating of bones.
However, the greater point is that on food consumption it's primarily a human/neanderthal game play element at the moment. When animal eating is tackled, placing dietary restrictions on animals is an interesting idea and it's very cool you're thinking about these things!
I've read about it. Still, it was surely more herbivorous than modern day bears and may have eaten meat because of extreme hunger or even lack of enough plants. I mean, Hippos are reported to eat dead hippos but they're still considered herbivores, and considering how close Cave Bears are to their omnivorous cousins I wouldn't be surprised.
Yeah, I gotta say I'm a bit obssesed with the animals xD