WASHINGTON — The reputation of enriched grains as a cornerstone of healthy eating may sustain undeserved collateral damage from the Dietary Guidelines Advisory Committee’s continued shift to a dietary-pattern focus shift rather than a nutrient-based focus in its deliberations, said Erin E. Ball, executive director of the Grain Foods Foundation.

Ms. Ball shared the GFF’s concerns with the DGAC in a July 3 letter to the Department of Health and Human Services, which together with the US Department of Agriculture, is responsible for publishing the Dietary Guidelines for Americans every five years.

The letter was written in response to a request at a May 10 DGAC public meeting for comments about “inclusion and exclusion criteria” for scientific research to be considered by the committee.  The letter is separate from one submitted to the HHS by the Grain Chain.

The shift to a focus on dietary patterns is “of particular concern in the scientific literature’s treatment of the grains category,” the GFF said.

The DGAC, in its 2020 Scientific Report, acknowledged that since the early 2000s, the focus of the Guidelines for “quantifying dietary exposures has moved from single nutrients or foods to dietary patterns as a way to more comprehensively represent the totality of the diet and nutrient profiles.”

The 2020 committee defined dietary patterns as “the quantities, proportions, variety, or combination of different foods, drinks, and nutrients in diets, and the frequency with which they are habitually consumed.”

“The approach of using dietary patterns as an assessment tool to determine diet quality provides a meaningful bridge toward disseminating messages intended to promote high-quality diets,” the 2020 committee said. “(Using the dietary patterns approach) recognizes that foods and their associated nutrients are known to have synergistic effects, complicating the detection of an effect of a single food or nutrient.”

In the letter, Ms. Ball noted that “unhealthy dietary patterns” frequently lump together red and processed meat, sugary foods and beverages, french fries, high-fat dairy products and refined grains.

While the pattern has been linked to increased risk of diet-related chronic disease, “each of these food/beverage items may not be equally culpable for the increased disease risks,” she said.

Whole grains and refined grains tend to be characterized by associations with dietary patterns rather than “on their own merits,” Ms. Ball said. The concern is not just theoretical but has been validated by a review of scientific studies.

“It is plausible that the risk associated with refined grain food intake, specifically, is not attributable to refined grain foods per se but rather to the other foods within the unhealthy dietary pattern,” the letter said. “In fact, a large and consistent body of evidence from meta-analyses of prospective cohort studies suggests that refined grain foods may not be a primary driver of health risks associated with a Western dietary pattern, but rather their categorization with other foods within that pattern.”

Commenting on guidance in earlier Dietary Guidelines for Americans to replace refined grain foods with whole grains, the GFF letter cited an issue noted by the 2015 DGAC, pointing out that “modeling consumption of all grain foods and whole grain foods, without including any enriched grain products, results in nutrient shortfalls, including folic acid, iron, thiamin, niacin, and riboflavin.”

The GFF also took issue with the tendency of research studies to lump into the refined categories indulgent foods (eg, cookies, donuts and pizza) with staples (eg, bread, white rice and pasta). Despite this broad-brush approach, the letter noted meta-analysis of six cohorts showing no statistically significant association between refined grain foods intake and cardiovascular disease risk.

“While some studies show a positive association between refined grain food intake and body mass index, these studies included indulgent grain foods in the refined grain food definition, making it impossible to separate the contribution of dietary staples and those that are indulgent ‘treats,’ which have lower nutrient density,” the GFF letter said.

Ms. Ball urged the DGAC to “disaggregate staple and indulgent grains to better understand their contributions to healthy and unhealthy dietary patterns and nutrient adequacy.” She said the committee should recommend this separated approach in future nutrition and dietary pattern research.