Brown rice is unmilled or partly milled rice. It is considered as a kind of whole grain I. E. Itâ¢s a natural grain that remains unbleached. Brown rice unlike white rice still has the side hull and bran. The side hulls and brans provide Ånatural wholeness to the grain and are rich in proteins thiamine calcium magnesium fiber and potassium. For those trying to lose weight or those suffering from diabetes brown rice can prove a healthful staple given its low glycemic rating which helps reduce insulin spikes.