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Throughout evolution, human
beings adapted to a wide range of naturally occurring
foods, but the types of food and the mix of nutrients
(in terms of carbohydrates, fats, and proteins) remained
relatively constant. Food supplies were often precarious,
and the threat of death from starvation was a constant
preoccupation for most early humans.
However, about 10,000 years
ago the agricultural revolution began making profound
dietary changes in many human populations. The ability
to produce and store large quantities of dried foods
led to preferential cultivation of some foods, such
as grains, which constituted new challenges to the human
digestive system. Then, about 200 years ago, the Industrial
Revolution introduced advances in food production, processing,
storage, and distribution. Recent technological innovations,
along with increased material well-being and lifestyles
that have allowed people more freedom in deciding what
and when they wish to eat, have led to even further
major dietary changes in developed countries. Because
changes in the dietary patterns of the more technologically
developed countries, such as the United States, have
been so dramatic and rapid, the people consuming these
affluent diets have had little time to adapt biologically
to the types and quantities of food that are available
to them today. The longer term adverse health effects
of the diet prevailing in these countries — characterized
by an excess of energy-dense foods rich in animal fat,
partially hydrogenated vegetable oils, and refined carbohydrates
but lacking in whole grains, fruits, and vegetables
— have become apparent only in recent decades.
Because of the recent,
rapid rise in chronic illness related directly or indirectly
to diet, the focus of nutrition research has shifted
away from eliminating nutritional deficiency to dealing
with chronic diseases caused by nutritional excess.
Another concern among nutrition researchers is the accumulation
of evidence indicating that a less-than-adequate intake
of some micronutrients, over a long period, may increase
the risks of developing coronary heart disease, cancers,
cataracts, and birth defects. In recent decades, the
data on the relationship between certain dietary habits
and nutritional intake have been growing exponentially.
Designing interventions based on this wealth of research
has become increasingly more difficult and complex.
The Federal Government’s
approach to dietary intervention, formulated by boards
composed of nutrition scientist, generally does not
recommend supplementing the typical American diet with
vitamins or nutrients beyond the recommended daily allowances
(RDAs), nor does it suggest that some foods never be
eaten. In contrast, many alternative dietary approaches
contend that no amount of manipulation of the typical
American diet is enough to promote optimum health or
prevent eventual chronic illness. These alternative
approaches represent a continuum of philosophies ranging
from the concept that supplementing the typical American
diet somewhat beyond the RDAs is necessary to promote
optimum health, to the idea that supplementation well
beyond the RDAs is often required to reverse the effects
of long-term deficiencies. Other approaches advocate
drastic dietary modification, either eliminating or
adding certain types of foods or macronutrients, to
treat specific types of conditions such as cancer and
cardiovascular disease. Finally, there is the view that
certain major staples of typical American diet, such
as meat and dairy products, are basically unhealthy
and should be generally avoided.
There is a growing body
of data supporting the notion that the RDAs for mineral,
such as calcium and magnesium, may be too low and that
supplementation may be necessary to prevent the onset
of chronic diseases. In addition, the RDAs for a number
of vitamins and micronutrients, such as vitamin C, vitamin
D, vitamin E, folate, and beta-carotene, may not be
adequate to prevent chronic illness. For example, recent
studies have found that the RDA for folate may need
to be doubled for women as well as men.
Orthomolecular medicine-the
therapeutic use of high-dose vitamins to treat chronic
disease-promotes improving health and treating disease
by using the optimum concentration of substances normally
present in the body. Increasing the intake of such nutrients
to levels well above those usually associated with preventing
overt deficiency disease may have health benefits for
some people. There is at least preliminary evidence
that orthomolecular remedies may be effective in treating
AIDS; brochial asthma; cancer; cardiovascular disease,
heart attacks, and stroke; lymphedema; and mental and
neurological disorders.
A variety of alternative
diets are offered for treating cancer, cardiovascular
disease, and food allergies. Virtually all of these
interventions focus on eating more fresh and freshly
prepared vegetables, fruits, whole grains, and legumes.
Allergy to food has become a major area of research.
Food intolerance is being studied as a causal or contributing
factor in rheumatoid arthritis, and there is evidence
that food-elimination diets may help many hyperactive
children.
Some alternate dietary
lifestyles are believed to offer a greater resistance
to illness. These include several variations of the
vegetarian diet, such as those consumed by Seventh-Day
Adventists and proponents of the macrobiotic diet. Studies
have found a significant lowering of risk factors for
heart disease and certain forms of cancer in these two
groups. Recent studies have also reported that certain
cultural eating styles, such as the Asian and Mediterranean
diets, appear to lower risk factors for heart disease
and certain forms of cancer as well. Although there
have been few controlled studies of the benefits of
many traditional diets, such as those originally consumed
by Native American Indians, diseases such as diabetes
and cancer were not a problem for these populations
until their diets became more Western, or affluent.
Because dietary and nutritional
therapy interventions affect an array of biochemical
and physiological processes in the body, evaluating
their effectiveness may require equally complex methods.
Furthermore, developing a comprehensive healthcare policy
that incorporates diet and nutritional interventions
may require taking into account Federal feeding programs
and dissemination strategies that might present barriers
to the effective propagation of adequate nutritional
knowledge.
Adapted from Alternative Medicine: Expanding Medical
Horizons, a report prepared under the auspices of
the Workshop on Alternative Medicine, held in Chantilly
VA on September 14-16, 1992.
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