Do you Know What 'Whole Grains' Actually Mean

Competing definitions of what whole grains actually are makes it difficult to evaluate the consumption among Americans

Highlights:

Eating whole grains is an important part of a balanced diet
Whole grains are known to reduce the risk of cardiovascular disease, diabetes, obesity, and cancer
New research shows that while consumption of whole grains has gone up, what whole grains actually mean is conflicting

Americans are consuming more whole-grain foods than ever before, according to a recent study. And do they actually understand what "whole grains" refers to?

Depending on whose definition of a whole-grain food is being employed, the rise in consumption of whole grains over the past two decades might be between 39.5% and 61.5%. Additionally, Americans’ mean intake of whole-grain items varied greatly by definition and remained much below the daily minimum recommendation of three ounces ().

Eating Whole Grains Increases Metabolism And Calorie Loss
A diet rich in whole grains not only helps in improving digestion but also helps in increasing the resting metabolic rate, an effect that is similar to exercise.

‘A new study shows that reaching a consensus on the definition of whole grains could help accurately evaluate their consumption in the American population.’

Epidemiological evidence suggests that high consumption of whole grains protects against cardiovascular disease, type 2 diabetes, cancer, and total mortality (). The 2015–2020 Dietary Guidelines for Americans (DGA) noted that distinguishing whole grains from refined grains is especially important because Americans are currently consuming enough grains daily; however, over 40% are not consuming enough whole grains ().

The greatest sources of whole grains in the diets of adults are yeast breads (27%), ready-to-eat (RTE) cereals (23%), and pastas, cooked cereals, and rice (21%) (). However, those food sources are not generally 100% whole grains. The American diet does not include many foods that are 100% whole grains, but rather foods that contain some small proportion of whole grains, such as breads, cereals, or pastries made with some whole grain flour. The US Food and Drug Administrations’ classification of whole grains is limited to those products which retain all of the main biological components of the grain (germ, endosperm, and bran) in the same relative proportion as in the intact grain (), which is not necessarily related to the amount of dietary fiber. Therefore, the “whole grain”-containing foods recommended by the DGA encompass a wide variety of foods, ranging from those with proportionally low amounts to those with very high amounts of dietary fiber, depending upon the type of grain.

The researchers say that there’s a clear need to standardize how consumers, researchers, and policymakers talk about whole-grain foods. The study compared overlapping definitions from five institutions: the Dietary Guidelines for Americans, the U.S. Food and Drug Administration (FDA), the American Heart Association, the American Association of Cereal Chemists International, and the Whole Grains Council. The research team applied the various definitions of a whole-grain food to the dietary intakes of over 39,700 adults captured by the National Health and Nutrition Examination Survey (NHANES) between 2003 and 2018.

Confusion Regarding Whole Grain Foods Definition

Researchers found that each definition captured very different types of grain- or flour-containing foods as whole-grain foods, resulting in differences in the average consumption of whole-grain foods and the associated trends. They also added that, as consumers, they have had the experience of struggling to identify what is or isn’t a whole-grain food via the packaging labels. Recent studies also suggest nearly half of American consumers have similar challenges ().

Whole Grains Vs. Refined Grains: Which is Better for Heart Health?
Can whole grains reduce heart disease risk? Yes, replacing refined grains with whole grains can lower the risk of premature coronary artery disease.

When looking at the different categories of whole-grain foods identified by these definitions, while some similarities were identified—whole-grain bread consumption increased under all definitions—there were more differences. The government-led FDA’s definition was the strictest, categorizing the fewest foods as whole-grain foods compared to the industry-led Whole Grains Council’s, which was the most lenient but could be the least healthy based on previous studies.

One surprising finding was how the foods of different population subgroups were classified depending on the applied definition. For example, individuals who are non-Hispanic white had a higher intake of whole-grain foods compared with other racial/ethnical groups under all definitions, except for the definition proposed by the American Heart Association, under which Hispanic individuals had the highest intake. The possible reason is that the American Heart Association’s definition is more sensitive to identifying dishes such as corn-based burritos, tacos, and nachos as whole-grain foods.

Whole Grains Reduce Inflammation, Help Lose Weight
Replacing refined grains with whole grains decreases body weight, serum inflammatory markers, interleukin and C-reactive protein.

Researchers state that they cannot evaluate the best definition yet since they need to assess the nutrient profiles of each and how these different definitions are associated with health outcomes. Their findings, however, underscore the imperative need for a consensus on whole-grain food definition. A consistent definition across agencies is essential to further promoting whole-grain food consumption in the U.S. population.

The definitions used to define whole grain foods affect the estimated mean and trends of whole grain foods consumed by US adults. This finding calls for a standard definition of whole grain foods across the nation to guide consumers and inform policy formulation to promote whole grain intake among Americans.

Whole Grains can Reduce the Risk of Developing Colorectal Cancer
Dietary fiber, especially from whole grains and cereals, is associated with a decreased risk of colorectal cancer.

References:

Trends in Whole-Grain Food Intake Among Adult Americans, 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 Intakes 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 Healthfulness in Product Labels: A Discrete Choice Experiment and Comprehension Assessment - (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8555857/)

Source-Medindia