“Eat more whole-grain foods” and “Eat more fruits and vegetables” are two recommendations with consensus among nutritionists and health professionals. The Food and Drug Administration has approved 14 health claims describing a relationship between a food substance and a disease or health-related condition, including one for whole-grain foods.
Twelve of these health claims are based on the standard of scientific validity, which requires that (1) the totality of evidence supports the substance–disease relationship and (2) there is significant scientific agreement among qualified experts that the relationship is valid.
The other two claims are based on the existence of an authoritative statement by an appropriate scientific agency of the United States. These two claims—for potassium and the risk of high blood pressure and stroke, and for whole-grain foods and the risk of heart disease and certain cancers—do not need the specific depth of scientific data required of the other 12 claims.
The authoritative statement for the whole-grain-foods claim appears in the National Academy of Sciences’ 1989 report, Diet and Health: Implications for Reducing Chronic Disease Risk: “Diets high in plant foods—i.e., fruits, vegetables, legumes, and whole-grain cereal—are associated with a lower occurrence of coronary heart disease and cancers of the lung, colon, esophagus, and stomach.”
FDA chose to authorize the whole-grain-foods health claim by using dietary fiber as the index for a standard of compositional identity. However, the agency did not establish a definition for whole grain. A clear standard of identity for a whole-grain status is not defined for any cereal. Maize, rice, and wheat are the three most abundant cereals produced in the world, and their annual production is approximately equivalent. Whole wheat is a common term well perceived among scientists and consumers—it is the kernel with its bran covering, complete aleurone layer, germ, and endosperm. Ground and or cracked whole wheat can be used to make many foods with high consumer acceptance. Low-extraction flour (72% and higher) has no bran and a minimum amount of aleurone layer. Adding wheat bran back to low-extraction flour will not constitute whole wheat.
For purposes of the health claim, whole-grain foods are foods that contain 51% or more of whole-grain ingredients. The current whole-grain health claim is applied most often to wheat. Four factors limit its application to other cereals: (1) the lack of an overall definition for whole grain; (2) the lack of whole-grain identification for cereals and other grains; (3) the specification that a whole-grain food must contain 51% or more whole-grain ingredients by weight per reference amount customarily consumed (RACC or RA); and (4) the specification that a whole grain must contain 11% total dietary fiber (TDF).
Establishing an identity for whole grains other than wheat is problematic and presents an issue that should be resolved. What constitutes a whole-corn product that can be used in foods? How can the fractions that constitute whole corn be described? Although it is difficult to envision a whole-corn-based cereal or bread, whole-corn snack foods (without salt and saturated fat) are more likely. Corn flakes are made with corn starch, but no added dietary fiber. However, corn flakes do contain dietary fiber (resistant starch). What, then, constitutes whole rice, and what fractions are included? Rice is usually steamed, but there are white rice and brown rice. Brown rice is perceived as more healthy, but only contains 3.5% TDF. Can white rice ever be described as a whole grain, or must a certain fraction of its aleurone layer remain on the endosperm to fit the definition for brown rice, the whole-grain (rice) entity? It is possible to grasp the idea of whole barley (hulled barley and or pearled), whole rye, and whole triticale, but what makes whole sorghum and whole millet acceptable ingredients?
With dietary fiber restrictions, the whole-grain-foods health claim usually applies to low-moisture foods such as cereals, popcorn, and possibly crackers. It would not usually apply to bread products and other intermediate-moisture cereal foods. It is difficult for an intermediate-moisture food to contain 51% of any whole grain per RACC. The standard serving size for bread is one slice, ranging in weight from 28 to 35 g. A serving size of bread could be increased to two slices of 50 g or more, but is this a counterproductive increase in energy? Yes, this is a possibility but not the best choice. The current whole-grain-health claim cannot be used for multi-grain whole-grain foods.
Based on the available data on the TDF content of whole cereals, only wheat, barley, sorghum, rye, and triticale would qualify as whole grains. Although there is an oat/oat bran health claim, common oatmeal cereal (oat groats) and other oat-based cereals do not have sufficient dietary fiber content to qualify for the whole-grain-food health claim. The average TDF content of oat groats is 9.5%.
Modifying the whole-grain-foods health claim to allow greater consumption of all grains would be nutritionally advantageous to the consumer and economically advantageous to the food industry.
by Dennis T. Gordon is Professor, Dept., of Cereal Science, North Dakota State University, Fargo, ND 58105.