There’s a new study conducted by University of California San Francisco researcher David Killilea that compares nutrient contents of wheat kernels, flours, and breads made with refined and whole wheat. The research tracked nutrient content from farm to table, revealing significant differences between the nutrients found in whole wheat and refined products.
The study shows that major minerals were reduced by up to 72% in refined flour and breads compared to whole wheat. Similarly, carotenoids and vitamin E saw substantial reductions during processing for both refined and whole wheat products when compared to raw wheat kernels. These findings highlight the importance of consuming a diet rich in whole grains over more refined wheat products due to their higher nutritional value.
Researchers used wheat kernels from a single farm source, transformed them into three types of flour, then baked breads. To assess nutrient levels, they took samples at each step – in the raw kernels, milled flours, and final baked breads.
For types of whole wheat flours – stone-milled and reconstituted – major mineral contents remained relatively unchanged along the process. In contrast, traces of minerals even slightly increased during processing. However, for the refined flours and breads made with them, major minerals saw drops of up to 72%. When it came to vitamin E and carotenoids, these were also more abundant in the raw kernels before processing, and significantly lowered in the final bread products with all flour types.
Currently, the Dietary Guidelines for Americans recommend that whole grains constitute at least half of one’s total grains intake but research shows most people fail to meet this recommendation. Future studies involving different farming or processing techniques on wheat and wheat products may improve nutrient density and address issues associated with vitamins A and E found in the US population.
Lastly, it is essential to point out that the study’s findings from NUTRITION 2024 are considered preliminary until a peer-reviewed journal publication is available.
