Variable definitions have been used to define whole grains, most of which focus on retention of similar proportions of bran, germ, and endosperm in wholemeal/wholegrain flour, as in the original kernel. Further distinction should be made to separate intact kernels (i.e. intact, unmilled whole grains) from milled whole grains (i.e. whole grain flours and the products made from them) in standardizing research, translation, and health communications. Additional issues include the effects of processing on changes in micronutrient/phytochemical composition, bio-accessibility and bioavailability, as well as on contamination and on alterations in metabolic responses.
Whole Grain Scientific Consensus