Agriculture Reference
In-Depth Information
tubers provided the main source of carbohydrates in a seasonal manner. Since the
geographic distribution of carbohydrate-rich foods did not overlap with all human
populations, some people consumed almost no food carbohydrate. Examples of this
are the arctic human populations of Inuits, whose carbohydrate consumption before
the arrival of Western civilization was almost nonexistent (McClellan and DuBois
1930; Gudmand-Hoyer and Jarnum 1969).
The development of agriculture marked a change in the type and quantity of car-
bohydrates available to humans (Dobrovolskaya 2005). This activity made available
for human consumption large quantities of grains with a high content of carbohy-
drates, particularly in the form of starch, which provided and exceeded their caloric
requirement. It is well accepted that the domestic crops of wheat, corn, rice, and
barley were the foundations on which diverse civilizations developed throughout
the world. Thus, starch derived from grain crops was the most abundant source of
carbohydrates during the preindustrialized centuries of human civilization.
Although apparently cane sugar or sucrose was known in Europe centuries before
Christ as part of imports from oriental countries, it was not until the colonization
of America that crystallized sucrose became an important source of sweet carbo-
hydrates for Western civilizations. Crops of cane sugar were among the first estab-
lished in the new world by the European settlers, and they remain as one of the most
important agricultural products for several countries of America and other develop-
ing countries (Tangley 1986; Japto 2000). However, the use of sucrose has remained
mostly as a food sweetener and candy component. The Industrial Age also had an
impact on the patterns of carbohydrate consumption by humans. Starch industrial-
ization with procedures for its refinement and transformation into syrups by chemi-
cal or enzymatic methods has become one of the most important sources of products
for production of a wide variety of foods. Simple carbohydrates, such as glucose and
fructose, are important components in commercial beverages and baking. Presently,
carbohydrates are available for human consumption in a multiplicity of forms and
products from a large variety of raw materials of diverse botanical origin.
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The rapid change in patterns of carbohydrate consumption by humans, from sparse
and occasional to daily large quantities, has not occurred without side effects on the
human physiology. Human physiology appears to be well adapted for consumption
of small quantities of carbohydrates distributed during the day, resembling the hypo-
thetical carbohydrate consumption of early humans (Dobrovolskaya 2005). When an
excess of carbohydrates was available for early humans, their storage in the form of
fats was important to provide energy requirements during times of low food avail-
ability. However, present feeding patterns for some humans involve the repeated
ingestion of relatively large quantities of carbohydrates in short periods of time. In
many cases, the energy intake exceeds the requirement, leading to the continuous
transformation and storage of carbohydrates in the form of body fat and causing
eventual development of obesity. In addition, the frequent glycemic overload result-
ing from the digestion and absorption of large quantities of carbohydrates imposes a
stress on the glycemic homeostatic mechanisms based on the pancreatic response of
