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02-11-2006, 06:21 PM

A facinating article putting a lot of threads in one place from a scientific perspective.

RB

http://www.ajcn.org/cgi/content/full/81/2/341

There is growing awareness that the profound changes in the environment (eg, in diet and other lifestyle conditions) that began with the introduction of agriculture and animal husbandry {approx}10000 y ago occurred too recently on an evolutionary time scale for the human genome to adjust. In conjunction with this discordance between our ancient, genetically determined biology and the nutritional, cultural, and activity patterns of contemporary Western populations, many of the so-called diseases of civilization have emerged. In particular, food staples and food-processing procedures introduced during the Neolithic and Industrial Periods have fundamentally altered 7 crucial nutritional characteristics of ancestral hominin diets: 1) glycemic load, 2) fatty acid composition, 3) macronutrient composition, 4) micronutrient density, 5) acid-base balance, 6) sodium-potassium ratio, and 7) fiber content. The evolutionary collision of our ancient genome with the nutritional qualities of recently introduced foods may underlie many of the chronic diseases of Western civilization.

Key Words: Westernized diets • chronic disease • processed foods • genetic discordance • hunter-gatherers • human evolution

EVOLUTIONARY DISCORDANCE
TOP
ABSTRACT
EVOLUTIONARY DISCORDANCE
CHRONIC DISEASE INCIDENCE
HOMININ DIETARY CHARACTERISTICS
NUTRITIONAL CHARACTERISTICS OF...
HEALTH RAMIFICATIONS OF FOODS...
SUMMARY
REFERENCES

Evolution acting through natural selection represents an ongoing interaction between a species’ genome and its environment over the course of multiple generations. Genetic traits may be positively or negatively selected relative to their concordance or discordance with environmental selective pressures (1). When the environment remains relatively constant, stabilizing selection tends to maintain genetic traits that represent the optimal average for a population (2). When environmental conditions permanently change, evolutionary discordance arises between a species’ genome and its environment, and stabilizing selection is replaced by directional selection, moving the average population genome to a new set point (1, 2). Initially, when permanent environmental changes occur in a population, individuals bearing the previous average status quo genome experience evolutionary discordance (2, 3). In the affected genotype, this evolutionary discordance manifests itself phenotypically as disease, increased morbidity and mortality, and reduced reproductive success (1-3).

02-11-2006, 06:21 PM	#1
Unregistered Guest Posts: n/a	discordance between our ancient, genetically determined biology and the nutritional, A facinating article putting a lot of threads in one place from a scientific perspective. RB http://www.ajcn.org/cgi/content/full/81/2/341 There is growing awareness that the profound changes in the environment (eg, in diet and other lifestyle conditions) that began with the introduction of agriculture and animal husbandry {approx}10000 y ago occurred too recently on an evolutionary time scale for the human genome to adjust. In conjunction with this discordance between our ancient, genetically determined biology and the nutritional, cultural, and activity patterns of contemporary Western populations, many of the so-called diseases of civilization have emerged. In particular, food staples and food-processing procedures introduced during the Neolithic and Industrial Periods have fundamentally altered 7 crucial nutritional characteristics of ancestral hominin diets: 1) glycemic load, 2) fatty acid composition, 3) macronutrient composition, 4) micronutrient density, 5) acid-base balance, 6) sodium-potassium ratio, and 7) fiber content. The evolutionary collision of our ancient genome with the nutritional qualities of recently introduced foods may underlie many of the chronic diseases of Western civilization. Key Words: Westernized diets • chronic disease • processed foods • genetic discordance • hunter-gatherers • human evolution EVOLUTIONARY DISCORDANCE TOP ABSTRACT EVOLUTIONARY DISCORDANCE CHRONIC DISEASE INCIDENCE HOMININ DIETARY CHARACTERISTICS NUTRITIONAL CHARACTERISTICS OF... HEALTH RAMIFICATIONS OF FOODS... SUMMARY REFERENCES Evolution acting through natural selection represents an ongoing interaction between a species’ genome and its environment over the course of multiple generations. Genetic traits may be positively or negatively selected relative to their concordance or discordance with environmental selective pressures (1). When the environment remains relatively constant, stabilizing selection tends to maintain genetic traits that represent the optimal average for a population (2). When environmental conditions permanently change, evolutionary discordance arises between a species’ genome and its environment, and stabilizing selection is replaced by directional selection, moving the average population genome to a new set point (1, 2). Initially, when permanent environmental changes occur in a population, individuals bearing the previous average status quo genome experience evolutionary discordance (2, 3). In the affected genotype, this evolutionary discordance manifests itself phenotypically as disease, increased morbidity and mortality, and reduced reproductive success (1-3).