After years of campaigns from both the US Department of Agriculture (USDA) and corners of the food industry, it has become conventional wisdom that consuming more whole grains is a good thing. There are good reasons for this assertion; whole grains tend to contain more fiber and nutrients — such as manganese, selenium, and thiamin — than their refined counterparts. But as a recent study shows, there are plenty of reasons to be skeptical of products that tout their whole-grain content.
The study, conducted at the Harvard School of Public Health and published in the journal Public Health Nutrition earlier this month, examined five different criteria for choosing products that contain whole grains: the industry-sponsored Whole Grain Stamp, a whole grain as the first ingredient, a whole grain as the first ingredient with no added sugars, the word “whole” before any grain in the ingredients list, and a ratio of 10:1 or lower of total carbohydrate to fiber. The USDA often recommends looking for a whole grain as the first ingredient in a food, while the American Heart Association recommends using the 10:1 ratio as a guide. The researchers studied numerous packaged food items and found that those containing the Whole Grain Stamp, as well as those listing a whole grain first or anywhere on the ingredients list, contained more fiber and were less likely to contain trans fat than foods that fulfilled none of the whole-grain requirements. However, these whole-grain-touting foods tended to contain greater amounts of sugar and calories than non-whole-grain foods.
The 10:1 carbohydrate-to-fiber ratio turned out to be the best indicator of nutrition, leading to foods with higher levels of fiber and lower levels of sugar and calories than any of the other whole-grain criteria. This standard, however, may not be as easy to follow as the others, since it requires reading a product’s nutrition label and performing arithmetic. As noted in an article on the study at MinnPost, even this standard may not offer the best possible way to evaluate a food’s nutritional value, since certain types of fiber that add few nutritional benefits may be added to a food and count toward the 10:1 ratio. The article also explains why the Whole Grain Stamp may be such a poor predictor of nutritional value: It signifies only that a food contains at least 51% whole grain by dry weight. This means that up to 49% of the food may consist of added fats, sugars, and other ingredients that are best avoided.
Do you make an effort to include whole grains in your diet? If so, do you use the Whole Grain Stamp as a guide? Do you find that the whole-grain content of foods has any impact, positive or negative, on your blood glucose level? Are certain whole grains, or means of preparing them, better than others? Are there other fiber-filled foods that you believe are better or more important than whole grains when it comes to blood glucose control? Leave a comment below!