Return to text.
*52 Named after Frederick Banting, the co-discoverer of insulin, a distant relative of William Banting, of corpulence notoriety.
Return to text.
*53 The reports do acknowledge, as the AHA-NIH-ADA conference report put it, that “very high-carbohydrate diets may accentuate atherogenic dyslipidemia”—i.e., small, dense LDL, high triglycerides, and low HDL—but then it recommends a high-carbohydrate, low-saturated-fat diet as the treatment.
Return to text.
*54 Ralph DeFronzo, on the other hand, believes that sufficient studies have confirmed Stout’s observations and that insulin itself should thus be considered an “atherogenic hormone.”
Return to text.
*55 This hypothesis cannot, however, explain why atherosclerosis among diabetics has remained relatively impervious to the otherwise beneficial effects of insulin therapy to control blood sugar.
Return to text.
*56 Those in Cerami’s laboratory at Rockefeller University and the researchers who trained with him get credit for much of the AGE work that followed.
Return to text.
*57 There’s also evidence that HDL molecules can become glycated, inhibiting their function and “rendering the HDL more pro-atherogenic.”
Return to text.
*58 For this reason, fructose is referred to as the most lipogenic carbohydrate. Credit for this observation dates to 1916, to Harold Higgins of the Nutrition Laboratory of the Carnegie Institution.
Return to text.
*59 Individuals with a single copy of this apo E4 gene are nearly three times as likely to have both heart disease and Alzheimer’s than those with none. Apo E4 is a cousin of apo B, the protein component of LDL and VLDL, and it is also found in the lipoproteins that transport triglycerides and cholesterol. Because heart-disease researchers have focused on cholesterol as the cause of heart disease, Alzheimer’s researchers tend also to refer to apo E4 as involved in cholesterol transport as though that were all it did, thus “point[ing] to a link between cholesterol and Alzheimer’s.” But this took the overly simplistic 1960s view of heart disease and used it to misdirect the Alzheimer’s research.
Return to text.
*60 Harvard neurologist Dennis Selkoe and others have been working to track down a gene that seems to predispose individuals to age-related Alzheimer’s, rather than the inherited early-onset form. By February 2007, they had not found it, but they had localized it, in the lingo, to a chunk of a single chromosome that was known to include the gene for insulin-degrading enzyme. This made IDE the obvious candidate and suggested that anyone who inherited a particularly unlucky variant of the IDE gene would have an increased likelihood of getting Alzheimer’s.
Return to text.
*61 Higginson held the environmental movement responsible for what he considered a willful misinterpretation of the epidemiologic observations: “If they could possibly make people believe that cancer was going to result from pollution, this would enable them to facilitate the clean-up of water, of the air, or whatever it is,” he told Science in 1979. He was all for cleaning up the environment, he added, but “to make cancer the whipping boy for every environmental evil may prevent effective action when it does matter.”
Return to text.
*62 Those clinical trials that tested the dietary-fat-and-fiber hypotheses of cancer, as we discussed earlier, replaced red meat in the experimental diets with fruits, vegetables, and whole grains. When these trials failed to confirm that fat causes breast cancer, or that fiber prevents colon cancer, they also failed to confirm the hypothesis that red-meat consumption plays a role in either.
Return to text.
*63 Tannenbaum actually compared his chronically underfed mice with control mice fed the identical diet but supplemented with cornstarch. The inhibition of cancer, as Tannenbaum noted, could have been due to “carbohydrate-restriction” rather than restriction of all calories.
Return to text.
*64 Different IGFs have different effects. To keep the following discussion reasonably simple, I’ll refer to IGF and IGF receptors as though there were only one species of each, although I’m oversimplifying the science by doing so.
Return to text.
*65 The apparent severity of this epidemic is inflated by the way in which obesity is defined. The use of a threshold for establishing whether or not you’re obese—a body mass index (BMI) of 30—means that one can move from the overweight category to the obese category by virtue of gaining a few pounds. As a result, the 10-percent rise in obesity between 1991 and 2000 actually represented an increase in the average BMI of Americans from 26.7 to 28.1, an average weight gain of seven to ten pounds.
Return to text.
*66 Between the second and third National Health and Nutrition Examination Study.
Return to text.
*67 The USDA has a variety of mechanisms for estimating macronutrient intake—i.e., protein, carbohydrates, and fat—and has published a variety of reports on the subject. Not all are consistent, but the findings on fat consumption are. For instance, in April 1998, the USDA published an article entitled “Is Total Fat Consumption Really Decreasing?” This article reported that average total fat consumption for men aged nineteen to fifty, for instance, dropped from 113 grams per day in 1977–78 to ninety-six in 1989, the period that encompasses the beginning of the obesity epidemic. The relevant numbers for women of the same age group are seventy-three grams of fat per day in 1977–78 and sixty-two in 1989.
Return to text.
*68 According to the Sporting Goods Manufacturers Association, sales of sporting equipment, apparel, and shoes increased from $21.9 billion in 1987 (the earliest year for which they have data) to $52 billion in 2004.
Return to text.
*69 If each Pima drank two eight-ounce soft drinks a day, this would add roughly two hundred calories a day to Hesse’s estimate of both carbohydrate and calorie consumption, and so would drop the fat in the diet to 22 percent.
Return to text.
*70 The Sioux were “essentially carnivorous” prior to their reservation life, the report noted, and so they “were never in the habit of eating much fruit and vegetables.”
Return to text.
*71 Hrdli
Return to text.
*72 In 1804 and 1805, when the Corps of Discovery under Meriwether Lewis and William Clark made their historic overland expedition to the Pacific Ocean, they described game so plentiful in places that they literally had to club it out of their way to make progress.
Return to text.
*73 This conclusion was supported four years later, when German researchers published their protocol for keeping these desert sand rats healthy in captivity. “It is well known that these animals will develop diabetes mellitus soon after their natural vegetative diet is removed and replaced with standard laboratory rations,” they noted. But both diabetes and obesity can be avoided if the animals are reared on a suitable diet: in this case, fruits, vegetables, and herbs, supplemented by an unlimited supply of insects, shrimps, worms, and grasshoppers.