In the 2015-2020 Dietary Guidelines for Americans, the federal government for the first time encouraged people to limit intake of refined grains. The recommendation reflected concerns that while overall grains intake for most Americans was nearly in line with dietary guidance, whole grains have accounted for far less than the recommended 50% of total grains intake and refined grains accounted for far more.
Since the guidelines were published, intake of refined grains has fallen, and the grain-free trend has gained momentum. Against this backdrop, an expert panel convened to explore the consequences of a move away from refined grains.
While the issues associated with the recommendations are complex, the researchers built their discussion on a straightforward question — do refined grains have a place in healthy dietary patterns? Their discussions and conclusions were published earlier this year in Current Developments in Nutrition. The paper’s authors include scientists currently or formerly associated with the Grain Foods Foundation, such as Yanni Papanikolaou and Glenn Gaesser, but also former members of the Dietary Guidelines Scientific Advisory Committee, such as Joanne L. Slavin and Roger Clemens.
In seeking to determine whether refined grains belong in a healthy diet, the researchers discussed four issues: 1) Can fortified/enriched grains add nutritional value to the diet? 2) Do refined grains contribute meaningfully to nutrient adequacy? 3) Are refined grain foods a contributing factor in overweight and obesity? and 4) Are there gaps in the scientific literature making answering these questions a challenge?
The questions posed by the researchers cut to the core of what the nutrition community should examine regarding the leading source of caloric intake in the American diet. In answering the questions, the panel both affirmed the valuable role grains play in delivering key nutrients to the public while also challenging as distorting the broad-brush manner too many researchers paint refined grains as indulgent and unhealthy.
Central to the panel’s conclusion that refined grains play a pivotal role in nutritional health is the importance of enrichment/fortification together with the reality that intake of whole grains remains far lower than recommended.
“Without enrichment and fortification practices currently in place in the United States, a substantial percentage of all children and adolescents would have inadequate intakes of numerous micronutrients, with the most concerning nutrient inadequacies affecting older adolescent females,” the panel concluded.
Ready-to-eat cereals, bread, rolls and tortillas “are meaningful contributors of nutrient density” across all age groups in the American diet, the panelists said.
Citing studies showing only 5% of Americans consume whole grains at the low-end of recommended intake, the researchers said it is refined grains that are key to ensuring Americans consume adequate levels of nutrients that include thiamin, folate, iron, zinc and niacin, as well as dietary fiber.
The researchers did not consider the potential value of reducing intake of indulgent refined grains such as cakes, cookies and pies as well as other grain foods containing elevated levels of sodium and saturated fat from the diet and suggested further research on the subject should be considered. But they criticized the manner in which researchers lump together products such as donuts and bread into a single category — refined grains.
“Classifying all grains that are not ‘whole grains’ into the one category of refined grains may not be a justified nor a nutritionally valid representation of the nutrient contribution provided by many nutrient-dense enriched grain foods,” the researchers said.
Suggesting the need for “further delineation,” the panel said, “Future research should consider distinguishing different types of refined grain foods with the goal of potentially creating an additional classification of grains that goes beyond whole and refined.”
Regarding obesity, the panel said reduced consumption of indulgent refined grains may be necessary, but current scientific evidence does not show refined grains raise the risk of overweight and obesity.
The panel’s common-sense conclusions should help reset the manner in which flour-based foods are viewed by the nutrition community and represent a resounding affirmation of the central role the category plays in healthy eating.