well in a way food can have medicinal properties. i admit that giving a depressed person a carrot may not do anything for them but making said carrot into a carrot cake (with the other food items that make it) may cheer them up a bit. most chemicals are distilled 'properties' from various herbs and plants, for example you can get loads of benificial chemicals out of the simple lavender bush (the essential oil if you want to get technical). iirc, paracetamol has some lavender based chemicals in it.

what im trying to say is that food is what you make of it, if you have the imagination and ambition. somehow though i doubt Eggers is capable of thinking like that. she isn't one for philosophising or for doing aromatherapy classes. which is a shame realy, she'd be less of a mary sue then.