The publishing of objective research plays an important part in our understanding of how the human body works. As scientific studies better demonstrate certain relationships between food and health, previous recommendations may be updated. The U.S. government, and others, often does this through their agencies such as the U.S. Department of Agriculture (U.S.D.A.). However, the process is often heavily influenced by large companies who spend billions of dollars on lobbying efforts to have their products included in recommendations, or at least to avoid having them be given a negative association with poor health—ongoing examples include sugar and processed flour.
Updates are also incorporated into recommendations made by healthcare practitioners to patients, such as when sufficient research shows eating certain foods are good or bad for health. At other times, research simply confirms what has already been known, either by previous research, through clinical experience, or both.
A consensus conference is one where a group of clinical and scientific researchers gather to discuss a particular topic, review the research, and try to come to an overall agreement on details of the issues. Such a consensus on dietary fat and its role in heart disease—the most common cause of death in most industrialized countries—took place last year with the results just published in the March 2011 issue of the American Journal of Clinical Nutrition. The good news is that an important consensus about diet and heart disease has been made among many experts in various fields of research. But what took so long?
For decades, cholesterol was the villainous cause of heart disease, so the public was told. By the 1970s, it was clear to me, and many other clinicians around the world, that this was not the case. Yet, simple cholesterol blood tests for total cholesterol—often done in shopping malls—frightened millions of people out of eating eggs for breakfast, despite the research showing that eating them won’t raise blood cholesterol. Instead, those millions, and many more, switched to a breakfast of processed cereal, which has been shown to contribute to the overfat epidemic, a much greater risk for heart disease.
As the value of “total cholesterol” campaign began to be questioned, another simple number took its place—low-density lipoprotein (LDL), a type of lipoprotein in the blood that transports cholesterol and triglycerides from the liver. Lobbied by pharmaceutical companies and their allies, LDL—the so-called “bad” cholesterol—has become the new simplistic single number guide in prescribing cholesterol-lowering drugs. But all along the way, the research was never so convincing.
One of the conclusions made at the recent consensus conference points to the long-standing, well-researched notion that the ratio of total cholesterol to the “good” HDL cholesterol is the best indicator of cardiac risk—better than the single LDL number. Why has this consensus taken so long? Perhaps it was the complex math—one must divide the HDL into the total cholesterol to obtain a final number. Or, the powers that be did not want to associate the term “good” with cholesterol. After all, mention the “c” word to the average English speaking person and it will conjure up “bad.” Or perhaps it disrupted the simplistic “one number-one prescription” idea useful for busy physicians. (I have read the studies that equate high LDL levels with heart disease, but I am also aware that for many of these patients the standard of care is to first address diet and exercise before cholesterol-lowering drugs are used. But that’s rarely done.)
The fact that cholesterol in the body is vital for millions of healthy processes is also something usually not discussed. Nor is the fact that most of the cholesterol in your blood, the so-called good and bad, is made by the liver, and it’s not there because of diet.
In addition to cholesterol, a consensus on the amount of triglyceride in the blood, another type of fat that rises when refined carbohydrates are consumed, has also been made—above normal levels increase the risk of heart disease because it’s associated with carbohydrate intolerance. So eating cereal for breakfast, a popular recommendation for decades by so-called experts, clearly can raise risk of heart disease by elevating triglycerides.
The consensus conference even showed signs of being holistic, emphasizing that a comprehensive evaluation for heart disease risk should be made up of “multiple biomarkers including total and HDL cholesterol, blood pressure, body fatness, glucose tolerance, and inflammatory markers.” Great. But what took so long? These were the very recommendations made 30 years ago by those of us who avoided the “eggs-are-bad” bandwagon.
In addition to eggs being considered unhealthy for the heart, meat has also been given a bad rap for decades. The consensus conference finally has differentiated between real meat and the many processed versions. “The epidemiologic data provide strong evidence that a high intake of processed meat products…is associated with an increased risk of heart disease.” These include cold cuts, packaged sliced meats, and ground meats used in frozen meals.
The consensus conference also concluded that there is no consistent evidence that a higher intake of dairy products is associated with the risk of heart disease.
The experts cautioned about making broad generalizations—“meat is bad” or “dairy is bad”—but noted that only a minority of different populations adhere to a healthy dietary pattern, defined as one high in vegetables and fruits that can include lean meats and dairy even in modest amounts.
The conference also highlighted health benefits of natural cocoa—not the popular chocolate products made from sugar and other unhealthy ingredients. Natural cocoa has a high content of saturated fat and phytonutrients, which can actually reduce the risk of heart disease.
Conference participants also emphasized the need for better and realistic research. For example, instead of just looking at the amount of saturated fat, studies are needed to examine individual foods, such as cheese and red meat, and the risk of disease in the context of a truly healthy dietary pattern.
In fact, the conference highlighted trends in the poor eating habits in the U.S. From 1971 through 2006, the eating habits of Americans aged 20 to 74 were evaluated. Carbohydrate intake increased significantly, while fat and protein was reduced—along the way obesity skyrocketed. Here are some of the findings:
- The prevalence of obesity increased from 11.9% to 33.4% in men and from 16.6% to 36.5% in women.
- The percentage of energy from carbohydrates increased from 44.0% to 48.7%.
- The percentage of energy from fat decreased from 36.6% to 33.7%.
- The percentage of energy from protein decreased from 16.5% to 15.7%.
- Caloric intake increased substantially, meaning that, since fat and protein intake was reduced, a significant intake of carbohydrate occurred.
The myth that protein is bad continues, often with dire consequences. The carbohydrate trend continues too, fueled by lobbying and million-dollar ad campaigns directed at children, despite the known health damage of these foods. Of course, for many, solving the problem starts with the “Two Week Test.”
Of course, fat phobia continues as well, including low- and no-fat products with less calories and added sugar—all while the overfat epidemic keeps growing. Fueled by refined carbohydrates, could this bring us to the end of the yellow-brick road?