Harvard researchers question whole grain standards
BOSTON — Researchers at Harvard School of Public Health are recommending adoption of a consistent, evidence-based standard for labeling whole grain foods after results from a new study found current standards are inconsistent and, in some cases, misleading.
The study, “Identifying whole grain foods: a comparison of different approaches for selecting more healthful whole grain products,” was published in the Jan. 4 advanced on-line edition of Public Health Nutrition.
As part of the study, researchers collected data on a total of 545 grain products from the on-line web sites of Wal-Mart Stores, Inc. (www.walmart.com) and Stop & Shop (www.peapod.com) between July 2010 and April 2011. The web sites were searched for all products in eight categories of frequently consumed grains, including bread, bagels, English muffins, cereals, crackers, cereal bars, granola bars and chips.
The researchers then evaluated five different criteria that have been recommended to help identify whole grains. Those criteria were:
• Presence of the Whole Grain Stamp
• Whole grain as the first ingredient on the ingredient list
• Whole grain as the first ingredient without added sugars
• Presence of the word “whole” before any grain anywhere in the ingredient list
• A ratio of total carbohydrates to fiber, in grams per serving, of less than or equal to 10:1. This ratio is approximately the ratio of carbohydrate to fiber in whole wheat flour, and is the standard used by the American Heart Association as part of its 2012 strategic impact goals to classify grain products as whole grains.
The least restrictive criterion was “whole” anywhere, which identified approximately 54% of the products, followed by the 10:1 ratio (41%) and whole grain first (40%). The Whole Grain Stamp and whole grain first without added sugars criterion were the most restrictive, identifying 21% and 17% of products as whole grain, respectively.
According to the researchers findings, the A.H.A.’s standard of a less than 10:1 ratio of carbs to fiber was the best indicator of overall healthfulness. The 10:1 ratio identified products less likely to contain trans fats, less sugar, less sodium and no energy differences.
“If this ratio is considered for broader policy or labeling use in the future, it may be preferable to limit the amount of added bran that can contribute to its calculation,” the researchers said. They added the information required for its calculation is readily visible on the Nutrition Facts Panel, but still requires some math that may be a challenge for some consumers.
The whole grain first without added sugars criterion performed similarly to the 10:1 ratio with respect to sugars, energy and trans fat, but such products did not contain less sodium and identified many fewer whole grain products (29) compared with the 10:1 ratio (222).
Meanwhile, products meeting the Whole Grain Stamp, whole grain first or “whole” anywhere criterion, identified products with less sodium, but more sugars and energy per serving.
“Overall, the 10:1 ratio appeared to be the best indicator, identifying foods with more fiber, less sugars and sodium, and less likely to contain trans fats, without energy increases,” the researchers noted. “The whole grain first no added sugars was useful in identifying products with more fiber and less sugars that were less likely to contain trans fats, but was not associated with lower sodium and was more restrictive in terms of the number of products it identified. The industry supported Whole Grain Stamp and the U.S.D.A.-recommended criteria for whole grain first and ‘whole’ anywhere each identified products with more fiber and less sodium, but also more sugar and energy. The 10:1 ratio and Whole Grain Stamp each identified products that were more expensive per serving.
“Our analyses suggest that using several of the readily available or recommended information on product packages and ingredient listings to select healthful whole grain products may be misleading for consumers and organizations (e.g. schools, workplace cafeterias). Although individual contents of sugars, sodium, energy and trans-fat are contained on product nutrition facts panels in many countries, consumers find it challenging to synthesize and interpret such detailed products nutrition listings and rarely use them effectively. Consequently, alternative and simpler methods are needed to assist consumers, food service personnel and policy makers in selecting healthful whole grain products that are higher in fiber and lower in sugars, sodium, trans-fats and energy.”
Elaborating on the usefulness of the Whole Grain Stamp, the researchers said its value is limited by the lack of consideration of other components in each product, as well as by the fact that it’s the only criterion determined by a food manufacturer’s own assessments and willingness to pay a fee for its use.
“Our analysis indicates that consumers may be misled by the promised healthfulness that the symbol implies,” the researchers said. “Whether or not a product contains whole grain is just one measure of healthfulness, and other factors must be considered. For example, the Whole Grain Stamp also identified products with significantly higher contents of sugars and energy, each of which are also important for health.”
Responding to the criticism, the Whole Grains Council posted a lengthy rebuttal to the study on its web site (http://wholegrainscouncil.org/newsroom/blog/2013/01/wgc-rebuts-harvard-study-stands-behind-wg-stamp). The W.G.C. noted that the motivation for the research was valid, but inaccuracies “bring into serious question the study’s data and its conclusions.” One of the W.G.C.’s concerns was that the study’s definition of a “whole grain ingredient” was based on an outdated and inaccurate list of 29 ingredients (including bran, psyllium husk etc.) that is no longer supported by U.S.D.A. nor in line with F.D.A. policy. Another concern was that the study was skewed toward products high in sugar and calories, especially when it came to the selection of products using the Whole Grain Stamp.
The Whole Grain Stamp was not alone in drawing the scrutiny of the researchers, though. They said the U.S.D.A.-recommended criterion of “whole” anywhere “was relatively unhelpful in identifying healthful products.”
“Because the word ‘whole’ can occur anywhere in the ingredient list, this criterion selected many products that are mostly refined grains with only small amounts of whole grains; it was also the only criterion that did not identify products less likely to contain trans fats,” researchers said. “In addition, this criterion may miss true whole grain products, as many such products may contain whole grain such as oats or barley that do not contain the word ‘whole’ before it.”