Agriculture Reference
In-Depth Information
2
The Evolving Knowledge
of Nutrition
Buford L. Nichols and Roberto Quezada-Calvillo
contents
Abstract .................................................................................................................... 15
What Is Nutrition?.................................................................................................... 16
What Is the History of Life? .................................................................................... 16
Genomic History of Digestion ................................................................................. 18
Protein Digestion................................................................................................. 18
Lipid Digestion.................................................................................................... 20
Carbohydrate Digestion ...................................................................................... 22
Milk Sugar...................................................................................................... 22
Table Sugar..................................................................................................... 23
Starch Digestion ............................................................................................. 23
Amylase Solubilization of Starch................................................................... 24
α-Glucosidase Digestion of Starch ................................................................ 24
Summary .................................................................................................................. 27
References................................................................................................................ 28
AbstRAct
In Chapter 1, the origins of agriculture were traced to a period of about 10,000
years ago when the hunter-gatherer lifestyle was replaced by farming. This “green
revolution” occurred in many locations and among many peoples. The diversity of
foods and food compositions before and after the first green revolution suggest that
fundamental genomic mechanisms exist to digest and utilize the broad spectrum of
human diets (Chapters 1, 3, 4). Some of the genes that express digestive enzymes,
such as amylase, are about 3.5 billion years old, as old as the first living cells. Other
genes, such as enterokinase, which regulates protein digestion, are as young as 0.5
billion years old (Hedges et al., 2004). These digestive genes are part of the genome
of all living organisms and are essential for maintenance, growth, and reproduction
(de Duve, 2007). Their generic nature permits the present and future diversity of
agriculture and food availability. As pointed out in Chapters 1 and 22, the growth of
global population is already placing strains on food availability and diversity. It is my
contention that greater understanding of basic human food needs, when coupled to
understanding of the spectrum of food genomes, can continue to evolve and sustain
global population growth and health through a new green revolution.
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