Josh Sosland
To the degree compliance is the ultimate measure of success for the Dietary Guidelines for Americans, the performance of the government recommendations would certainly receive a failing grade. Even amid evidence that the science underpinning the Guidelines is stronger than ever, more than 90 per cent of Americans fail to consistently follow the D.G.A. Widespread confusion about and skepticism toward often contradictory dietary advice contribute to the gaping difference between the Guidelines and the public’s eating habits.

Recognizing that something is amiss, the National Academies of Sciences, Engineering and Medicine has published two reports in recent months with recommendations to revamp the process for establishing the Dietary Guidelines. Several of the recommendations are of great interest to grain-based foods. If the changes will bring still greater scientific rigor to the process, the recommendations should be embraced.

Amid the N.A.S. recommendations is a distinction between eating as a means toward nutrient delivery and more complex and poorly-understood effects eating has on health. The report advocates systems-level approaches to the study of nutrition with the hope of “elucidating the interactions and pathways (e.g., biological, behavioral, social and environmental) involved in complex relationships, such as the relationship between diet and health.” More specifically, the N.A.S. believes systems science will clarify the connection of diet and chronic disease.

An approach used with success in recent years in fields as disparate as transportation and meteorology, systems approaches will require something of a “cultural shift” for the D.G.A., requiring researchers to begin their inquiries with a systems map and model to begin charting relationships and potential mechanisms connecting food with a health outcome. An iterative process, the model would be used to establish research priorities and guide data collection and interpretation.

As a hypothetical example of a topic that may benefit from a systems approach, the N.A.S. cited the potential connection between saturated fat and coronary artery disease. While research suggests excessive intake of saturated fat may lead to lipid deposits within blood vessel walls leading to a cascade of responses culminating in heart disease and potentially death, the group notes there are many intermediate physiological steps and “potentially modifying factors” that are important to track before definitive conclusions may be reached. The same may be said about the associations between chronic disease and flour-based foods.

The field of systems science has blossomed thanks to advances in computing systems and computational methods and capabilities, the N.A.S. says. A vigorous advocate for a systems approach has been Bruce Y. Lee, an associate professor at the Johns Hopkins Bloomberg School of Public Health in Baltimore.

“The tendency in the past has been to look at things in a very binary manner,” Dr. Lee said. “This food is associated with disease, so it’s bad. Or this is not associated with disease, and it’s good. That’s not how life works. That’s certainly not how nutrition works. Systems approaches help better understand connections and risk, and I think there is the potential of a lot more clarity if systems approaches are used. If we don’t, there is almost certain risk of continuing to think of nutrition in a binary manner.”

How much time would elapse before such an approach yields measurable results is difficult to precisely pinpoint, Dr. Lee says, but he predicted progress would be recognizable as early as the 2020 Guidelines with an even more significant impact by 2025. A precise understanding of the connection between eating and chronic disease may take considerably longer.

It is impossible to predict what kind of recommendations, positive or less so, would be generated from systems approaches with regard to grain-based foods. Given the industry’s longstanding commitment to science-based recommendations, its fundamental confidence in the healthfulness of grains and the negative default position toward bread already assumed by so many consumers as well as those in the media and academia, the clarity that may result from systems approaches is worth exploring.