Health Ramifications of Neolithic and Industrial Era Foods

The novel foods (dairy products, cereals, refined cereals, refined sugars, refined vegetable oils, fatty meats, salt and combinations of these foods) introduced as staples during the Neolithic and Industrial eras fundamentally changed a number of major nutritional characteristics of ancestral hominin diets and ultimately had far-reaching effects on health and well being. As these foods gradually displaced the minimally processed wild-plant and animal foods in hunter-gatherer diets, they adversely affected the following dietary parameters: (1) glycemic load, (2) fatty acid composition, (3) macronutrient composition, (4) micronutrient density, (5) acid/base load,(6) sodium/potassium ratio, and (7) fiber content.

1. The Glycemic Load
The glycemic index, originally developed in 1981, is a relative comparison of the blood-glucose-raising potential of various foods or combination of foods based on equal amounts of carbohydrate in the food (Jenkins et al., 1981). In 1997, the con- cept of glycemic load (glycemic index×the carbohydrate content per serving size) was introduced to assess blood-glucose-raising potential of a food based on both the quality and quantity of dietary carbohydrate (Liu and Willett, 2002). Refined grain and sugar products nearly always maintain much higher glycemic loads than unprocessed fruits and vegetables (Foster-Powell, Holt, and Brand-Miller, 2002). Unrefined wild-plant foods, like those available to contemporary hunter-gatherers, typically exhibit low glycemic indices (Thorburn, Brand, and Truswell, 1987). Within the past two decades, substantial information has accumulated showing that long-term consumption of high glycemic load carbohydrates can adversely affect metabolism and health (Liu and Willett, 2002; Ludwig, 2002; Cordain, Eades, and Eades, 2003). Specifically, chronic hyperglycemia and hyperinsulinemia, induced by high glycemic load carbohydrates may elicit a number of hormonal and physiological changes that promote insulin resistance (Liu and Willett, 2002; Ludwig, 2002; Cordain, Eades, and Eades, 2003). Diseases of insulin resistance are frequently referred to as “diseases of civilization” (Eaton, Konner, and Shostak, 1988; Reaven, 1995) and include obesity, coronary heart disease, type 2 diabetes, hypertension, and dyslipidemia (elevated serum triacylglycerols; small-dense, low-density lipoprotein cholesterol; and reduced high-density lipoprotein cholesterol). It is likely that the
metabolic syndrome may extend to other chronic illnesses and conditions that are widely prevalent in western societies, including myopia, acne, gout, polycystic ovary syndrome, epithelial cell cancers (breast, colon, and prostate), male vertex balding, skin tags, and acanthosis nigricans (Cordain, Eades, and Eades, 2003). Diseases of insulin resistance are rare or absent in hunter-gatherer and other less-
westernized societies living and eating in their traditional manner (Schaeffer, 1971; Trowell, 1980; Eaton, Konner, and Shostak, 1988). In addition to high glycemic load carbohydrates, other elements of Neolithic and Industrial era foods may contribute to the insulin resistance underlying metabolic syn- drome diseases. Milk, yogurt, and ice cream, despite having relatively low glycemic loads are highly insulinotropic, with insulin indices comparable to white bread (Ostman, Liljeberg Elmsthal, and Bjorck, 2001). Fructose is a major constituent in high fructose corn syrup (table 19.2) and maintains a low glycemic index of 23 but paradoxically may worsen insulin sensitivity (Reiser et al., 1989) and cause acute insulin resistance in humans (Dirlewanger et al., 2000). In the typical U.S. diet, high glycemic load sugars now supply 18.6 percent of total energy, whereas high glycemic load, refined cereal grains supply 20.4 percent of energy (table 19.2). Hence, at least 39 percent of the total energy in the typical U.S. diet is supplied by foods that may promote insulin resistance. Although high glycemic load
sugars and grains now represent a dominant element of the modern urban diet, these
foods were rarely or never consumed by average citizens as recently as 200 years ago
(tables 19.3–19.5).

2. The Fatty Acid Composition
Chemically, fats are defined as acylglycerols, compounds in which a fatty acid… L.Cordain