Epidemiological evidence suggests that high consumption of whole grains protects against cardiovascular disease, type 2 diabetes, cancer, and overall mortality (
). The 2015-2020 Dietary Guidelines for Americans (DGA) noted that distinguishing whole grains from refined grains is especially important because Americans currently consume enough grains daily; but more than 40% do not consume enough whole grains (
).
The largest sources of whole grains in adults’ diets are yeast breads (27%), ready-to-eat (RTE) cereals (23%), and pasta, cooked grains, and rice (21%) (4).✔ ✔Reliable Source
Ten-Year Trends in Fiber and Whole Grain Intake and Food Sources for the United States Population: National Health and Nutrition Examination Survey 2001-2010
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). However, these food sources are generally not 100% whole grains. The American diet does not include many foods that are 100% whole grains, but rather includes foods that contain a small portion of whole grains, such as breads, cereals, or pastries made with whole grain flour. The US Food and Drug Administration’s classification of whole grains is limited to products that contain all the major biological components of the grain (germ, endosperm, and bran) in the same proportions as the whole grain (5).✔ ✔Reliable Source
Industry and FDA Staff Draft Guidance: Whole Grain Label Statements
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), which is not necessarily related to the amount of dietary fiber. Therefore, the “whole grain” foods recommended by the DGA cover a wide range of foods, depending on the type of grain, from those that are relatively low to those that are very high in dietary fiber.
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The researchers say there is a clear need to standardize how consumers, researchers and policymakers talk about whole-grain foods. The study compared overlapping definitions from five agencies: the Dietary Guidelines for Americans, the US Food and Drug Administration (FDA), the American Heart Association, the American Cereal Chemists International Association, and the Whole Grains Council. The research team applied different definitions of whole grain food to the dietary intake of more than 39,700 adults captured by the National Health and Nutrition Examination Survey (NHANES) between 2003 and 2018.
Confusion over the definition of whole grains
The researchers found that each definition included many different types of grain or flour-containing foods, such as whole-grain foods, resulting in differences in average consumption of whole-grain foods and related trends. They also added that as consumers, they have experience struggling to determine what is or isn’t whole grain food through package labels. Recent studies also show that nearly half of American consumers experience similar problems (6✔ ✔Reliable Source
Consumer confusion about whole grain content and health on product labels: a discrete choice experiment and perception assessment
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).
When looking at the different categories of whole grain foods defined by these definitions, while some similarities were found—whole grain bread consumption increased under all definitions—there were more differences. The government-led FDA’s definition was the strictest, classifying the fewest foods as whole grains, compared to the industry-led Whole Grains Council, which is the most lenient but may be the least healthy based on previous research.
A surprising finding was how the foods of different population subgroups were classified depending on the definition applied. For example, non-Hispanic white individuals had higher intakes of whole grains than other racial/ethnic groups under all definitions except the definition proposed by the American Heart Association. A possible reason is that the American Heart Association’s definition is more sensitive to identifying corn-based foods like burritos, tacos, and nachos as whole-grain foods.
The researchers say they still cannot assess the best definition because they need to evaluate the nutrient profiles of each and how these different definitions relate to health outcomes. But their findings underscore the importance of consensus on the definition of a whole grain food. A consistent definition among agencies is essential to further promote whole grain food consumption in the US population.
The definitions used to define whole-grain foods affect the estimated averages and trends of whole-grain foods consumed by US adults. This finding calls for a standard definition of whole grain foods across the country to guide consumers and inform policy formulation to promote whole grain intake among Americans.
References:
- Trends in Whole-Grain Food Intake Among American Adults Based on Different Definitions of Whole-Grain Foods, NHANES 2003-2018 – (https://academic.oup.com/cdn/article/5/Supplement_2/1027/6292704)
- Health Benefits of Dietary Fiber – (https://onlinelibrary.wiley.com/doi/10.1111/j.1753-4887.2009.00189.x)
- Dietary Guidelines for Americans – (https://health.gov/sites/default/files/2019-09/2015-2020_Dietary_Guidelines.pdf)
- Ten-Year Trends in Fiber and Whole Grain Intake and Food Sources for the United States Population: National Health and Nutrition Examination Survey 2001-2010 – (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4344579/)
- Draft Guidance for Industry and FDA Staff: Whole Grain Label Statements – (https://www.fda.gov/regulatory-information/search-fda-guidance-documents/draft-guidance-industry-and-fda-staff-whole-grain-label-statements)
- Consumer Confusion About Whole Grain Content and Health on Product Labels: A Discrete Choice Experiment and Comprehension Assessment – (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8555857/)
Source: Medium