Onion

Onions eaten raw will deliver the maximum of their benefits. That is not a reason to do it. Onions:

has a stimulating effect on the mucus membranes of the digestive organs.
is high in sulfur which is good for your hair, nails and skin.
can be considered a cancer-fighting food along with other members of the allium family (such as: garlic, shallots, scallions and chives.)
contains quercetin which is good for allergy sufferers.