Can african greys eat brazilian nuts?

The short answer is 'Yes, they will' eat peanuts, but as to how healthy it is, or how often they should be allowed to, I'm not sure.

Some commercial Parrot foods will contain both shelled and/or unshelled peanuts but I can't say if this is a dietary supplement, optional variety or cost saving measure.

When in doubt always speak with a qualified and knowledgeable veterinarian!