As if wading through the mystifying world of whole grains weren’t confusing enough, a new Harvard study found that “current standards for classifying foods as ‘whole grain’ are inconsistent and, in some cases, misleading.”
According to the study by Harvard School of Public Health researchers, the widely used "whole grain stamp" identified grain products that were indeed higher in fiber and lower in trans fats, but also had more sugar and calories compared with products without the stamp.
According to the stamp’s website, “Each ‘stamped’ product guarantees you at least half a serving of whole grains. The stamp makes it easy to get your recommended three servings or more of whole grains each day: Eating three whole grain food products labeled ‘100% whole grain’ does the trick — or six products bearing ANY whole grain stamp.”
The U.S. Department of Agriculture’s 2010 Dietary Guidelines does recommend that Americans eat at least three servings of whole grain products daily. However, there is no single standard for defining any product as a “whole grain,” says the study’s researchers.
“Given the significant prevalence of refined grains, starches and sugars in modern diets, identifying a unified criterion to identify higher-quality carbohydrates is a key priority in public health,” said first author Rebecca Mozaffarian, project manager in the Department of Social and Behavioral Sciences at HSPH.
To conduct the study, researchers assessed five industry and government guidelines for whole grain products:
Then they identified 545 grain products in eight categories from two U.S. grocers: breads, bagels, English muffins, cereals, crackers, cereal bars, granola bars and chips. They collected nutrition content, ingredient lists and the presence or absence of the whole grain stamp on product packages from all of these products.
The result: The American Heart Association’s standard — a ratio of total carbohydrate to fiber of less than 10:1 — proved to be the best indicator of overall healthfulness. Products that met this ratio were higher in fiber and lower in trans fats, sugar and sodium, without higher calories.
Soon after the study was published, the whole grain stamp responded to the conclusion that its products contain more sugar and more calories than products without the stamp.
Firstly, “the stamp was designed to denote the whole grain content of products and nothing more, and it has always been represented as such,” according to the release.
Secondly, the stamp says that the study’s definition of a “whole grain ingredient” is based on an “outdated and inaccurate list” of 29 ingredients (including bran and psyllium husk) that the USDA no longer supports and are not in line with FDA policy. The list also includes ingredients that are not whole grains and leaves out others — hulled barley, millet, quinoa, teff, durum wheat, etc. — accepted as whole grains.
In addition, “the study is not representative of whole grain products with the stamp.” Out of 543 products included in the study, only 113 with the stamp were selected. And those 113 products represent only 1.7% of the products using the stamp in the United States.
The study covered only chips, breads, cereals, bars and crackers, which are in only 10 of the 49 categories in the Stamped Products database. Rice and other “plain grains,” pasta, flours, oatmeal, tortillas and other categories are not included in the study.
According to the stamp, the study is skewed toward products higher in sugar and calories, “especially in its selection of products using the stamp.”
The stamp “encourage[s] a follow-up study that more accurately reflects the actual makeup of the whole grain stamp program and includes the pros and cons of all approaches to whole grain labeling — including the major drawbacks of the 10:1 ratio.”
In the meantime, check out our guide to navigating the bread aisle to choose the “real” whole grain options. Some of the health benefits of choosing whole grain foods? Lower risk of cardiovascular disease, weight gain and Type 2 diabetes, and lower levels of “bad” LDL cholesterol.