Good Calories, Bad Calories

The coming chapters will discuss the history of the science of metabolic syndrome both in the context of how the research was interpreted at the time, in a universe dominated by Keys’s hypothesis, and then how it arguably should have been interpreted if the research community had approached this science without bias and preconceptions. The next five chapters describe the science that was pushed aside as investigators and public-health authorities tried to convince first themselves and then the rest of us that dietary fat was the root of all nutritional evils. These chapters divide the science of metabolic syndrome and the carbohydrate hypothesis into five threads, to simplify the telling (although by doing so, they admittedly oversimplify).

The first (Chapter 9) covers the research that directly challenged the fundamental premise of Keys’s hypothesis that cholesterol itself is the critical component in heart disease, and instead implicated triglycerides and the kinds of molecules known as lipoproteins that carry cholesterol through the blood, both of which are effectively regulated by the carbohydrate content of the diet rather than saturated fat. The chapter then explains how this research, despite its refutation of the fat-cholesterol hypothesis, has been assimilated into it nonetheless.

The second thread (Chapter 10) follows the evolution of the science of insulin resistance and hyperinsulinemia, the condition of having chronically elevated insulin levels, and how that emerged out of attempts to understand the intimate relationship of obesity, heart disease, and diabetes and led to the understanding of metabolic syndrome and the entire cluster of metabolic and hormonal abnormalities that it entails.

The third (Chapter 11) discusses the implications of metabolic syndrome in relation to diabetes and the entire spectrum of diabetic complications.

The fourth (Chapter 12) discusses table sugar and high-fructose corn syrup, in particular, and the research suggesting that they have negative health effects that are unique among refined carbohydrate foods.

The last section of this history (Chapter 13) discusses how metabolic syndrome, and particularly high blood sugar, hyperinsulinemia, and insulin resistance, have physiological repercussions that can conceivably explain the appearance of even Alzheimer’s disease and cancer.

Throughout these five chapters, the science will be more technical than has typically been the case in popular discussions of what we should eat and what we shouldn’t. I believe it is impossible, though, to make the argument that nutritionists for a half century oversimplified the science to the point of generating false ideas and erroneous deductions, without discussing the science at the level of complexity that it deserves.

Chapter Nine

TRIGLYCERIDES AND THE COMPLICATIONS OF CHOLESTEROL

Oversimplification has been the characteristic weakness of scientists of every generation.

ELMER MCCOLLUM, A History of Nutrition, 1957

THE DANGER OF SIMPLIFYING A MEDICAL ISSUE for public consumption is that we may come to believe that our simplification is an appropriate representation of the biological reality. We may forget that the science is not adequately described, or ambiguous, even if the public-health policy seems to be set in stone. In the case of diet and heart disease, Ancel Keys’s hypothesis that cholesterol is the agent of atherosclerosis was considered the simplest possible hypothesis, because cholesterol is found in atherosclerotic plaques and because cholesterol was relatively easy to measure. But as the measurement technology became increasingly more sophisticated, every one of the complications that arose has implicated carbohydrates rather than fat as the dietary agent of heart disease.