Threats to the Dietary Guidelines for Americans

11/20/2015 - Congress passed the Bipartisian Budget Act last week. The next step is to determine how much money will be allocated to programs; however, lawmakers have also included controversial policy riders, one of which limits the scientific process that creates the Dietary Guidelines for Americans.

What are the Concerns with the Senate Appropriations Bills?

Only Conclusions with a Preponderance of Evidence

In the Senate, the Labor-HHS and Agriculture appropriations bill states that only recommendations that have a preponderance of evidence by the Nutrition Evidence Library (NEL) can be reported in the DGA. However, this limits the scope of some recommendations that cannot meet this stringent requirement. This is illogical when reviewing science as differences between studies can be explained by study designs or analysis tools utilized. Many important findings by the committee such as evidence linking cancer risk and dietary factors would be cut from the 2015 DGA because they do not meet the standard. This narrow focus would set a dangerous precedent making it more difficult for making changes to future DGA and therefore offsetting their original intent, to prevent disease and promote health of Americans.

Limited to Diet and Nutrient Intake

The Labor-HHS and Agriculture appropriations bill in the Senate would limit the scope of the 2015 DGA to diet and nutrient intake only, completely eliminating sections relating to food safety, lifestyle modifications, physical activity, and food insecurity which are proven to influence chronic disease and public health. Additionally, the 2015 DGA would not be allowed to explain how to best implement the recommendations made in the report.

These limitations on topic and scope are arbitrary and block the 2015 DGA from fulfilling their purpose. Nutrition science is constantly evolving and the updated guideline should reflect the current status of the evidenced-based guidelines. The Dietary Guidelines are critical to provide a basis for federal nutrition policy, to detect gaps in research, and to provide health professionals with evidenced-based recommendations to relay to the public.

What are the Concerns with the Language in the House Appropriations Bills?

Allows Only "Grade 1: Strong" Evidence

In the House, both the Agriculture (section 734) and Labor-HHS (section 232) appropriations bills state that only recommendations given a "Grade I: Strong" evidence by the Nutrition Evidence Library (NEL) can be reported in the DGA. However, only statements that had practically uniform results across a large number of studies are given a "strong" grading. This is illogical when reviewing science as differences between studies can be explained by study designs or analysis tools utilized. Furthermore, allowing only "strong" graded recommendations would be inconsistent with the 2010 DGA. Some recommendations from the 2010 DGA were given a "moderate" grading and those would still be included in the 2015 DGA. Finally, many important findings by the committee such as evidence linking cancer risk and dietary factors would be cut from the 2015 DGA because of their "moderate" grade. This narrow focus would set a dangerous precedent making it more difficult for making changes to future DGA and therefore offsetting their original intent, to prevent disease and promote health of all Americans.

Limited to Diet and Nutrient Intake

Again, both the Agriculture and Labor-HHS appropriations bills in the House would limit the scope of the 2015 DGA to diet and nutrient intake only, completely eliminating sections relating to food safety, lifestyle modifications, physical activity, and food insecurity, which are proven to influence chronic disease and public health. Additionally, the 2015 DGA would not be allowed to explain how to best implement the recommendations made in the report.

Additional Time for Public Comment

The bills also state that there be another 90 days for public comment. In the process of creating the 2015 DGA, the public had approximately 24 months to submit written comments through the Committee's process. Once the committee released their report, the public was given an additional 75 days to comment. Allowing more time for public comment would delay the law and waste federal resources as an additional comment period was not originally budgeted.

Conclusion

These limitations on topic and scope are arbitrary and block the 2015 DGA from fulfilling their purpose. Nutrition science is constantly evolving and the updated guideline should reflect the current status of the evidenced-based guidelines. The Dietary Guidelines are critical to provide a basis for federal nutrition policy, to detect gaps in research, and to provide health professionals with evidenced-based recommendations to relay to the public.

Recommendations that do not Make the Strong Grade: Examples

Example 1

The DGAC concurs that adults who would benefit from blood pressure lowering should "Consume no more than 2,400 mg of sodium/day." The report also indicates that "Further reduction of sodium intake to 1,500 mg/d can result in even greater reduction in blood pressure"; and concludes that "Even without achieving these goals, reducing 149 sodium intake by at least 1,000mg/d lowers blood pressure."

  • AHA/ACC Grade: Moderate
  • DGAC Grade: Moderate

Example 2

The 2015 DGAC concurs with the 2010 DGAC that "a moderate body of evidence has documented that as sodium intake decreases, so does blood pressure in children, birth to age 18 years."

  • DGAC Grade: Moderate

Example 3

Moderate evidence from prospective cohort studies indicates that higher intake of added sugars, especially in the form of sugar-sweetened beverages, is consistently associated with increased risk of hypertension, stroke, and CHD in adults. Observational and intervention studies indicate a consistent relationship between higher added sugars intake and higher blood pressure and serum triglycerides.

  • DGAC Grade: Moderate

Example 4

The DGAC concurs with the World Health Organization’s commissioned systematic review that moderate consistent evidence supports a relationship between the amount of free sugars intake and the development of dental caries among children and adults. Moderate evidence also indicates that caries are lower when free sugars intake is less than 10 percent of energy intake.

  • DGAC Grade: Moderate

Example 5

For people with physical disabilities, moderate evidence indicates that physical activity improves a variety of functional health outcomes and reduces the effects of certain types of secondary conditions (i.e., pain and fatigue associated with the primary disability); and for people with cognitive disabilities, moderate evidence indicates that physical activity improves cardiorespiratory health outcomes, musculoskeletal fitness, and metabolic health, and helps maintain healthy weight.

  • DGAC Grade: Moderate

Example 6

Consistent evidence indicates that, in general, a dietary pattern that is higher in plant-based foods, such as vegetables, fruits, whole grains, legumes, nuts, and seeds, and lower in animal based foods is more health promoting and is associated with lesser environmental impact (GHG) emissions and energy, land, and water use) than is the current average U.S. diet. A diet that is more environmentally sustainable than the average U.S. diet can be achieved without excluding any food groups. The evidence consists primarily of Life Cycle Assessment (LCA) modeling studies or land-use studies from highly developed countries, including the United States.

  • DGAC Grade: Moderate

Example 7

Sodium, Adults (Part D Chapter 6)

Blood Pressure:

  • Benefit blood pressure to lower sodium intake
    • Grade: Strong
  • Consume no more than 2,400 mg of sodium a day; greater reduction in blood pressure with a reduction in sodium to 1,500 mg/day
    • Grade: Moderate
  • Combine DASH diet with lower sodium intake to lower blood pressure
    • Grade: Strong

CVD:

  • There is a positive association between higher levels of sodium and risk of CVD
    • Grade: Moderate
  • Inconsistent or insufficient to conclude that lowering sodium intakes below 2,3000 mg/day either increases or decreases risk of CVD outcomes
    • Grade: Not assignable
  • A reduction in sodium by 1,000 mg/day reduces CVD by 30%; higher dietary sodium associated with fatal and nonfatal stroke and CVD
    • Grade: Limited
  • There is insufficient evidence to determine the association between sodium intake and the development of heart failure
    • Grade: Not assignable

Sodium and potassium on blood pressure and CVD:

  • Not sufficient to determine if potassium intake lowers blood pressure
    • Grade: Not assignable
  • Higher dietary potassium intake is associated with lower risk for stroke.
    • Grade: Limited
  • Evidence not sufficient to determine association between potassium and CHD, heart failure, and CV mortality
    • Grade: Not assignable

Example 8

Sodium, Children

As sodium intake decreases, so does blood pressure in children, birth to age 18.

  • Grade: Moderate

Example 9

Red and Processed Meat (Part D Chapter 2)

  • Decreased risk for CVD for diets lower in red and processed meat
    • Grade: Strong
  • Diets lower in meats (including red and processed meats) are associated with favorable outcomes related to healthy body weight or risk of obesity
    • Grade: Moderate
  • Diets lower in red meat are associated with reduced risk for type 2 diabetes
    • Grade: Moderate
  • Diets lower in red and processed meat are associated with reduced risk for colon/rectal cancer
    • Grade: Moderate