Evidence-Based Oncology

Dietary Patterns, and Effect on Cancer, Get Attention From Advisory Panel

Published Online: March 20, 2014
Mary K. Caffrey
Back in 1977, when a committee convened by then–US Senator George McGovern, D-SD, took the first official look at the American diet, the big concern was nutrient deficiency: in other words, what’s missing that might make people sick?1

How times have changed.

On January 13-14, 2014, when the 2015 Dietary Guidelines Advisory Committee (DGAC) met in Bethesda, Maryland, the worries were generally not about too little but too much: Americans are making themselves sick alright, but most of the evidence concerns what we’re putting in our diets, not what we’re leaving out.

Rates of diabetes and obesity are soaring, especially in the Southeast, and at least part of this difference is attributed to the regional diet2. Institute of Medicine Senior Scholar J. Michael McGinnis, MD, MA, MPP, opened the session with an historical overview of the Dietary Guidelines process, and noted that 500,000 Americans now die each year due to poor diet and exercise habits—more than die from smoking.1,3

But as McGinnis and DGAC Chairwoman Barbara E. Millen, DrPH, RD, made clear, the 2015 guidelines cycle is not happening in a vacuum: the process, which occurs every 5 years and rotates between the US Departments of Agriculture and Health and Human Services (HHS), will unfold within HHS as the Affordable Care Act (ACA) takes hold across the country.

Looking to Improve Population Health McGinnis, when asked how the guidelines could engage primary healthcare providers, said he was encouraged with the creation of accountable care organizations, as envisioned in the ACA. McGinnis noted that the ACA not only calls for the improvement of population health but for primary and specialty care providers to “look beyond the clinic doors” and speak to a “broad set of factors” that affect the health of every American, and require primary care physicians to be engaged.

The next day, after public testimony had concluded, Millen opened reports of the subcommittees with a clear link to healthcare reform. The 2015 guidelines, she said, have the potential to affect “the implementation of the Affordable Care Act, the accountable care organizations,” national prevention strategy, as well as grant funding within the National Institutes of Health and the Centers

for Disease Control and Prevention. She then outlined what is good and bad about both the food and the healthcare systems.

The US population, she said, has the finest healthcare innovations in the world, including the best cancer care, but access to care is “variable.” The nation needs to shift its attentions from a preoccupation with treatment to a system based on prevention. Despite what employers and families spend on healthcare, there are wide healthcare disparities, Millen said. “We have preventable disease morbidity and chronic disabilities, and they account for half of the nation’s health burden.”

Is there a link between these facts and what Americans eat? Millen seemed to suggest so. “One in 6 households are food insecure, and two-thirds of the population is overweight or obese…we suffer from poor dietary patterns,” she said. “Foodborne illnesses have reached 76 million annually, accounting for 325,000 hospitalizations and 5000 deaths each year.”

Despite the many strengths of the agriculture and food distribution systems, Millen said, many experts believe that the committee must find solutions to these problems, and it must act aggressively to tackle diabetes and obesity, to do something about healthcare disparities among certain groups, to moderate alcohol use, and to lower metabolic risk factors. “These are the questions that are on the minds of the DGAC,” Millen said. For the first time, Millen said, the committee will include in the evidence base what it finds about connections between dietary patterns and cancer risk, including not only known relationships, but also what can be done to reduce cancer risk in the population through the foods Americans eat.

A “Systems” Approach

Millen, DGAC Vice Chair Alice Lichenstein, DSc, and the 2 returning members from 2010, Miriam Nelson, PhD, and Rafael Perez-Escamilla, PhD, have formed a science review subcommittee that is ensuring that the committee takes a “systems approach,” and examines dietary patterns and best practices, rather than just go food by food, or ingredient by ingredient. In fact, the third presenter at the January 13 session, Susan Krebs-Smith, gave the panel an overview of how to evaluate diets based on different systems approaches. Millen called for looking at “what works” at both a population level and at an individual level. The 2015 committee will continue its predecessor’s work in examining the effects of the places where people eat, cultural factors, and access to quality food, but it will dig deeper to examine the connection with help outcomes, Millen said.

This approach is more novel than it might seem. Past DGAC reviews have been criticized for being captive to corporate food groups; indeed, those interests gave it their best during the morning session of January 14. A literal smorgasbord of professionals paraded to the microphone, representing sugar, salt, potatoes, California walnuts, the American Meat Institute, nonalcoholic beverages, Ocean Spray cranberries, McDonald’s, juice products, Dannon yogurt, food technologists, egg farmers, the Tea Council, the National Cattlemen’s Beef Association, candy and gum, pistachio growers, and the United Fresh Produce Association, among others. Most interests came armed with a registered dietitian, and everyone had studies to support giving their product a place at the table.

How food-specific the DGAC’s recommendations will be remains to be seen. Anna Maria Siega-Riz, PhD, RD, who chairs the largest and most critical subcommittee on “Dietary Patterns, Foods and Nutrients, and Health Outcomes,” explained in the afternoon session January 14 that her panel will first examine dietary patterns, and from those results will take its work into specific foods.

She did not directly answer a question from Nelson on how the subcommittee would tackle thorny topics such as sugar-sweetened beverages, which has been the subject of important research since 2010, as well as high-profile public policy initiatives in New York City, Mexico, and the United Kingdom; and dairy, which dominated testimony in the public hearing January 14.

The Importance of Sustainability

Some topics of the January 13-14 meeting were anticipated: given the public flap over a May IOM study that did not support sodium intake below 2300 mg per day, it was hardly surprising when a Salt Institute lobbyist asked the committee to take the “courageous step” of calling for more salt in American diets.4

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