This study investigates whether current systems of whole wheat production and labeling meet consumer expectations for “whole wheat”: a reasonable belief that 100% or certainly most of the kernel (“whole”) is contained in the output of any whole wheat mill and therefore any product made from it. Dr. David Killilea developed a procedure for accurately determining levels of whole wheat in products labeled “whole grain” or “whole wheat,” taking measurements of a biomarker protein (wheat germ agglutinin—WGA) present in the germ of the wheat kernel.
When consumed as whole grain, wheat has a high nutrient density that contributes to a healthy diet. Yet, products labeled as whole wheat can still contain a substantial amount of refined grain leading to the confusion for consumers, so a method was designed to determine the whole grain status within wheat‐based foods. Wheat germ agglutinin (WGA), a lectin found in the germ tissue of wheat kernels, was evaluated as a biomarker of whole grain wheat. WGA content strongly correlated with the percentage of whole wheat within premade mixtures of whole and refined (white) flours. Then, commercial flours labeled as whole wheat were tested for WGA content and found to contain up to 40% less WGA compared to a whole grain standard. Commercial pasta products labeled as whole wheat were also tested for WGA content and found to contain up to 90% less WGA compared to a whole grain standard. The differences in WGA content were not likely due to varietal differences alone, as the WGA content in common varieties used in domestic wheat flour production varied less than 25%. The levels of other constituents in wheat kernels, including starch, mineral, phytate, and total protein, were not different among the commercial whole wheat flours and pasta products. WGA is a unique biomarker that can identify wheat products with the highest whole grain content.
The study finds that national brand pastas labeled “whole grain” and “100% whole wheat” have a range of whole grain content from as little as 9% of the nutrient rich germ that one would expect, to 22% germ content. National brand “100% whole grain” flours were found to be as little as 60% to 70% whole grain, as measured by germ content.
Above figure, published on ResearchGate –Quantification of WGA protein in commercial wheat flour and pasta products.
Above figure, published on ResearchGate: Information on commercial wheat flour and commercial wheat pasta products used in these studies. Product brand, description, and SKU/UPC number are shown.
Regulations: Labeling standards and guidelines for “whole wheat-food” (as it is called by the FDA) allow significant content variation in foods labeled “whole grain” and “whole wheat” (terms commonly used interchangeably). Furthermore, the FDA guidelines for “whole grain” describe and recommend procedures for industrial roller milling of the wheat kernel—bran, germ, and endosperm—that separate, sift, and then recombine, not necessarily in the kernel’s entirety. The FDA does not suggest, let alone mandate, a laboratory analysis of the output of the milling process. So what the consumer might learn is what went into the process, not much about the flour that comes out of it.
Health implications: Numerous large-scale studies in the US and Europe have shown that consumption of whole wheat reduces many age-related diseases (including cardiovascular disease, Type 2 diabetes, and colo-rectal cancers), as well as over-all mortality. Strong implications for reduced risk of dementias have also been found.
Nutrition: The nutrient density of true whole wheat is prodigious. Compared with refined flour (that is, endosperm minus bran and germ), whole wheat contains almost all of the vitamins and minerals found in the kernel, plus fiber and important phytochemicals. Defenders of the industrial grain milling process note that nutrients and fiber missing from white and industrial whole wheat flours are commonly available in other foods, but fail to add that they remain absent from most persons’ diets as documented by USDA data which show dramatic nutrient deficiencies within the US population. Those deficiencies would be substantively alleviated—if not totally reversed—by true whole grain wheat consumption at government-recommended levels. (See graph below)
Nutrient bang for the buck: Wheat is a major part of the US diet, providing an estimated 20 to 40% of US caloric intake. The potential for significant health benefits across the entire population could be realized with greater consumption of true whole wheat.
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It is essential to establish an accurate biochemical analysis of wheat food labeled “whole grain” or “whole wheat” at the point of completed processing so consumers can make better-informed dietary choices, scientists can work from a universally accepted baseline definition of “whole grain” for studies on the health effects of whole grain consumption, and so regulators would be motivated to develop more accurate, enforceable labeling standards. “Nutrition Facts” panels should include this information.