Comments for the USDA 2015 Dietary Guidelines

I submitted the following comments to the USDA website under Comment ID #6699.

USDA Dietary Guidelines and Reversing Trends of Metabolic Syndrome

The following are comments to the U.S. Department of Health and Human Services (HHS) and the U.S. Department of Agriculture (USDA) regarding the Scientific Report of the 2015 Dietary Guidelines Advisory Committee (Advisory Report) with suggestions for changes to the Dietary Guidelines for Americans.

Thank you for considering my comments and suggestions. My views are from review of scientific research, publications of credentialed health professionals, personal experience, observation, anecdotal evidence, and common sense. The comments are based on my belief that the metabolic syndrome epidemic is primarily caused by the following attributes of the American diet:

  1. Processed seed and vegetable oils that have replaced quality fats
  2. High-carbohydrate and low-fat macronutrient ratios
  3. Excessive consumption of grains and sugars

These characteristics have become increasingly common during the last 40 years in conjunction with increases in chronic diseases and obesity. I am certain HHS and USDA are aware of existing science regarding this. In addition, HHS and USDA must know that a growing number of health professionals have realized that errors in nutrition recommendations have been made in respect to these attributes. Some indication of this comes from the Advisory Report which includes recommendations to limit sugar and recognition that dietary saturated fat is not the cause of heart disease. My concern is that improvements this information brings to the guidelines will not be enough to substantially change the diet attributes listed above. The main suggestion I have is that changes be made to the guidelines which are significant enough to resolve the generally poor condition of American’s health.

Excerpts from Part D, Chapter 6 of the Advisory Report are shown below with comments that follow.

Advisory Report: It is now well-established that higher intake of trans fat from partially hydrogenated vegetable oils is associated with increased risk of CVD and thus, should be minimized in the diet.

Trans fat is often in processed foods, even when nutrition labels lists “0 trans fat”, due to inaccurate labeling and because the presence of trans fat does not have to be reported when there is less than 0.5 grams per serving. It is likely that people who regularly eat processed foods unknowingly ingest damaging amounts of trans fat from heat-processed seed and vegetable oils even when they pay attention to food labeling. Additionally, some vegetable oils sold for restaurant use include trans fat. Although the manufacturers properly disclose the existence of trans fat on the bulk packaging, restaurant consumers are unaware of the amounts in their food.

Simply stating that trans fat should be minimized, as the Advisory Report suggests, will not be enough to make significant changes. The guidelines and associated communications should provide clear warnings, particularly regarding processed seed and vegetable oils. Americans should be alerted to the risk of undisclosed trans fat in processed foods sold with nutritional labeling and in restaurants. They should also be alerted to other health issues associated with processed vegetable and seed oils, such as the chemicals used in processing these foods and the fact that use of these oils has resulted in an imbalance of omega-6 to omega-3 types of fat. The USDA is still recommending consumption of margarine and the new dietary recommendations must correct this.

Advisory Report: Numerous RCTs [randomized control trials] have demonstrated that saturated fat (SFA) as compared to mono- (MUFA) or polyunsaturated fats (PUFA) or carbohydrates increases total and LDL cholesterol.

It is good that saturated fat increases HDL and there should be no concern that it increases LDL. Both total and LDL cholesterol metrics are not good predictors of mortality and low LDL is associated with risk for dementia(1). Consider a study where admission lipid levels were documented in 136,905 patients with coronary artery disease (CAD)(2). Before admission, only 21.1 percent of the patients were receiving lipid-lowering medications. Mean lipid levels were LDL 104.9, HDL 39.7, and triglyceride 161 mg/dL, indicating that patients with CAD had relatively low HDL and high triglycerides. CAD patients with LDL over 100 mg/dL had LDL levels that were lower than patients without a history of the disease. Almost half of the patients were admitted with low levels of LDL 100 mg/dL.

Figure 1 represents some of the data. A reasonable target for LDL is 100-130 mg/dL and the data indicate that most of the patients were in this range or had lower levels. It is more important to be in the population with relatively high HDL and, of course, this can increase through consumption of saturated fats such as coconut oil and butter. Having low triglycerides is also important because, in addition to CAD risk, high triglycerides can increase risk for dementia(1). As Mayo Clinic and other sources have stated, exercise and reduction of carbohydrates can lower triglyceride levels.

Advisory Report: However, recent meta-analyses of prospective observational studies did not find a significant association between higher saturated fat intake and risk of CVD in large populations.

Advisory Report: Although saturated fat intake has declined in the past decades, current intake is still high at a median of 11.1 percent of daily calories.

This seems to suggest that saturated fat intake is still considered a problem. If it is a problem, please clearly reference why it is a problem in the guidelines and avoid bringing confusion to this subject. It is interesting that people are consuming less saturated fat while metabolic disease is worsening. The lean human body has evolved to contain 16 to 22 percent saturated fat so it seems unlikely that this is a heart-threatening substance. The recommendations and guidelines need to be clear regarding saturated fat.

Advisory Report: Strong and consistent evidence from RCTs shows that replacing SFA [saturated fatty acid] with unsaturated fats, especially PUFA [polyunsaturated fatty acid], significantly reduces total and LDL cholesterol.

This would have been be a good place to state that dietary saturated fat improves HDL levels. It is important that we get back to a ratio of about one to one of omega-3 to omega-6 fats. With processed foods and the types of fat currently recommended by the USDA such as margarine, Americans are getting as much a 25 times the omega-6 type of fat to omega-3. Any recommendations to increase polyunsaturated fats needs to be qualified to address this. Risks associated with processed vegetable oils must be clearly stated as well.

Advisory Report: Replacing SFA with carbohydrates (sources not defined) also reduces total and LDL cholesterol, but significantly increases triglycerides and reduces HDL cholesterol.

Along with blood pressure, the most important blood metrics are triglyceride and HDL cholesterol levels so this is extremely important. Since, for a low mortality risk, triglycerides should be low with a high HDL level, the guidelines should recommend foods that result in a triglyceride to HDL ratio of less than one. Specifically, it is important to recommend a low-carbohydrate high-fat (LCHF) diet. There are now over 25 million Americans who eat high-carb low-fat diets who are on statin drugs while much evidence shows that the critical blood lipid metrics, such as LDL particle size and HDL/triglyceride levels, are dramatically improved through eating LCHF unprocessed real food. To a degree, the rate of increased statin use is being slowed because of knowledge sharing through social media and other online sources. However, the Dietary Guidelines could be more influential in helping to achieve a near-zero statin drug use. It is good that the science committee published effects of carbohydrates on blood lipid metrics, and this needs to be strongly emphasized.

Advisory Report: Strong and consistent evidence from RCTs and statistical modeling in prospective cohort studies shows that replacing SFA with PUFA reduces the risk of CVD events and coronary mortality.

Advisory Report: However, reducing total fat (replacing total fat with overall carbohydrates) does not lower CVD risk.

Advisory Report: Consistent evidence from prospective cohort studies shows that higher SFA intake as compared to total carbohydrates is not associated with CVD risk.

This and other science-based information regarding macronutrient ratios should be strongly identified in the dietary guidelines. Changes to the guidelines should be basic enough to affect the USDA’s MyPlate icon and other public communications. It is well understood that dietary fat is essential and the recommendations need to result in quality fats appearing on the plate icon from sources such as butter, fish, olives, avocados, macadamia nuts, and coconuts. It would be beneficial to also identify healthy sources of unprocessed PUFA, such as from walnuts and flax seeds, and note the potential risk of heat-processed seed and vegetable oils.

Grains were a minor part of our ancestral diet and should no longer be heavily promoted by the guidelines. Even whole grains can produce damaging glycemic loads. For instance, two slices of whole wheat bread will spike blood sugar more than a typical candy bar. Fruits and vegetables are more healthy sources of fiber and micronutrients. Even people who eat a high-carbohydrate diet, but one that consists primarily of fruits and vegetables, can be significantly healthier than people who eat a grain-based diet. Currently only one of the two essential macronutrients (protein) is explicitly shown on the MyPlate icon. The entire grains section of the plate should be replaced with the words “Quality Fats” so both of the essential macronutrients are depicted. Perhaps it would be more clear to reinstate an inverted version of the USDA’s food pyramid without referencing grains.

The knowledge that over-consumption of carbohydrates causes obesity was common sense during the first half of the twentieth century. Unfortunately, standard nutrition education and protocol has changed to favor an extreme high-carbohydrate diet. The committee’s findings are science-based, although the science that gets published can be selective due to agendas and there is a great deal of other evidence and common sense supporting health benefits of LCHF diets that cannot be ignored. For instance, consider the testimonies from the thousands of people who successfully use information presented by cardiologist Dr. William Davis, author of Wheat Belly. It would not be sensible to ignore the extensive amounts of this type of information nor can I ignore my personal positive experience with a LCHF diet. Also, consider what would be necessary to feed laboratory rats to induce metabolic syndrome for the purpose of study. This is not a difficult problem for scientists since the standard commercial rat chow for this purpose is a high-carbohydrate diet. What if you wanted to reverse the symptoms? Scientists know that a ketogenic diet is proven to reverse the symptoms. It is simple: sugar makes us fat and fat makes us thin. Insulin resistance caused by glycemic load is a major factor for obesity and type 2 diabetes. Science indicates this and the relevant information should be in the guidelines. At some point, this will become common sense.

Again, in the past, people commonly recognized that high carbohydrate diets cause obesity. Unfortunately, the mindset of most people has changed and now a prevailing belief is that many high carbohydrate foods are very healthy, such as whole grain cereals, even though they produce high glycemic loads. Some of these products are even labeled “heart healthy”. Health conscience parents are giving their babies “natural” fruit drinks that include 24 grams of sugar per one small serving. Seniors are targeted by marketers of liquid food supplements, supposedly recommended by dieticians, which can be accurately described as sugar-milk. Fat is extracted from yogurt, sugar is added, and people believe this is a good product for health and losing weight. A better general understanding of nutrition is needed. It may be that our government should not be in the business of issuing dietary guidelines. Nevertheless, as long as this is happening, we had better get it right and make substantial changes that reverse the conditions causing the current health disaster.

The 2015 Dietary Guidelines Advisory Committee took small positive steps in making recommendations to reduce carbohydrate consumption. However, continuing recommendations that result in Americans eating an extreme high-carbohydrate diet (45-65 percent of calories) would contribute to continuation of our health problems. Carbohydrate consumption has increased since the USDA began issuing dietary guidelines(3) although the level of carbohydrate consumption has not exceeded the guidelines. Changes regarding macronutrients need to be substantial enough to reverse the trends and worsening health conditions. The revisions need to ultimately drive significant changes to USDA communications such as the MyPlate icon. After the revisions, the MyPlate Facebook page will no longer post photos of whole grain pancakes with the insinuation that this constitutes a healthy breakfast. The USDA’s SuperTracker website will no longer suggest eating margarine and there will be no promotion of low-fat food products.

The USDA appears to be influenced by the grain industry. The USDA website states there is a “strategic alliance” with a group of companies called The Grain Chain, consisting of American Bakers Association, Wheat Food Council, Grains Food Foundation, National Pasta Association, USA Rice Federation, General Mills, and Kellogg’s. As a result, it can be expected that any fundamental changes to the nutritional guidelines will be resisted by several industries. Please ignore special interests and only consider the health of Americans. It will be necessary to make fundamental changes that remove grains from one-quarter of the plate icon and identify fats at levels that more closely match our ancestral diet.

Grains, sugar, and fructose from corn are extensively used in processed foods and drinks, which make up about 80 percent of inventory in grocery stores. To be economical, many of these foods require the long shelf life and relative low expense of unhealthy heat-processed seed and vegetable oils. Consequently, the processed food industry will also have to be disrupted so it will be necessary to counter powerful economic and political forces. The bold changes that are needed will ultimately result in food products being generally much different than they are today and chronic diseases will again be at relatively low levels that existed 50 years ago.

Changes to the guidelines must be focused on the goal of improving health, which is proven achievable through simple changes in diet. Do not be sidetracked by problems of ecology at this time, no matter how important they are or even no matter how related they may be to nutrition. Our nation is becoming increasingly unhealthy and this can ultimately lead to weakness that prevents us from solving any problems. Ignore all special interests and change the guidelines. Without significant changes to basic attributes of our diet, the metabolic syndrome epidemic will continue and the CDC’s predictions of increased obesity rates will happen.

Figure 1:

Distribution of LDL levels at admission for patients with and without history of atheroscierotic vascular disease or diabetes

References:

  1. Plasma lipids and cerebral small vessel disease, Sabrina Schilling, Christophe Tzourio, Carole Dufouil, et al. Neurology 2014;83;1844-1852
  2. Lipid levels in patients hospitalized with coronary artery disease: An analysis of 136,905 hospitalizations in Get With The Guidelines Sachdeva, Amit et al. American Heart Journal , Volume 157 , Issue 1 , 111 – 117.e2
  3. Statistical review of U.S. macronutrient consumption data, 1965–2011 Americans have been following dietary guidelines, coincident with the rise in obesity Cohen, Evan et al. Nutrition
Advertisements