I agree with Ly&Pigs on this 100%.
I used to give my guinea pigs those things, and they never got negative health benefits, though. Why? Because they never ate them!
And if they did, it wouldn't have been good for them anyway. Those things contain I don't know what! Visible, though: sunflower seeds, bits of dried banana (can guinea pigs eat banana anyway??) and some unidentifiable powerdy stuff.
My piggies favourite treat is the occasional slice of apple. I'm eating apple right now, if I go see my piggies they'll all be licking my fingers!