Encyclopedia of Health and Medicine

appetite 177
elderly. NUTRITIONAL DEFICIENCY and MALNUTRITION
can develop rather quickly, initiating a cascade of
health consequences that can be difficult to
reverse. It is important for caregivers and healthcare
providers to monitor dietary intake and nutrition
in the elderly, to make sure food and nutrient
consumption is adequate. Basic NUTRITIONAL ASSESS-
MENT should be a component of most visits to the
doctor and of every ROUTINE MEDICAL EXAMINATION.
Maintaining Healthy Nutrition
Across the Age Spectrum
Healthy eating habits support the body in maintaining
optimal health at any age. In combination
with appropriate daily physical exercise, adequate
nutrition often is the difference between full
recovery and prolonged or incomplete recovery
from health conditions that arise. These lifestyle
factors also lower the risk for numerous health
conditions.
See also CARDIOVASCULAR DISEASE PREVENTION; DIET
AND HEALTH; LIFESTYLE AND HEALTH; NUTRIENTS; OBESITY
AND HEALTH; PREVENTIVE HEALTH CARE AND IMMUNIZA-
TIONS.
antioxidant A biochemical substance that
attracts free radicals, unmatched molecules
remaining as the waste byproducts of oxidation
functions (energy conversion and release) within
the body. Free radicals are associated with numerous
health conditions, especially chronic diseases,
though researchers do not yet fully understand
their roles. Free radicals bind with other molecules,
hijacking them from their intended destinations.
The resulting rogue molecules do not have
legitimate functions within the body and disrupt
normal cellular functions. When an antioxidant
molecule binds with a free radical, the resulting
structure becomes a readily identifiable waste
molecule that the body’s natural processes then
eliminate from the body.
Antioxidants are abundant in fruits and vegetables.
The body also synthesizes some antioxidants
such as COENZYME Q10. Carotenoids (components of
vitamin A), vitamins C and E, the mineral selenium,
and phytochemicals such as flavonoids and
plant sterols are among the common dietary
antioxidants. SOY, GREEN TEA, and GINKGO BILOBA are
particularly high in such phytochemicals.
Research suggests antioxidants play a vital role in
stopping cancers before they gain any momentum
as well as in slowing the progression and damage
of chronic conditions such as ATHEROSCLEROSIS and
DIABETES.
Though many NUTRITIONAL SUPPLEMENTS contain
antioxidants, food-based antioxidants appear to
have more potent effects through their numerous
though little-understood interactions with one
another. One exception is coenzyme Q10, which
does not come from dietary sources but rather
through processes within the body. Coenzyme
Q10 supplements boost coenzyme Q10 levels in
the body to have apparently the same effects as
endogenous coenzyme Q10. Minerals such as copper
and zinc help the body use antioxidants more
effectively.
See also NUTRITIONAL THERAPY; PHYTOESTROGENS;
SUN’S SOUP; VITAMIN AND MINERAL THERAPY.
appetite The sensation of feeling the desire to
eat. Appetite represents complex hormonal, neurologic,
and environmental interactions that correlate
in varying proportions both to HUNGER, the
body’s physiologic signal that it needs food, and to
learned behaviors for eating. Seeing, smelling, and
thinking about food often trigger appetite. Many
people also feel the desire to eat at conventional
meal times, regardless of whether their bodies
actually need food. Emotional circumstances may
trigger appetite as well, particularly when there is
an emotional or habitual connection between eating
and feeling comforted.
The Mechanisms of Appetite
Three regions of the BRAIN work in collaboration
and counterbalance to regulate appetite: the
appetite center, the SATIETY center, and the hunger
center. The appetite center resides within the
brainstem, the most rudimentary structure of the
brain that regulates functions necessary for survival.
It responds to external sensory NERVE signals
from the body that travel to the brain via the CRA-
NIAL NERVES as well as to nerve signals that come
from the cerebral cortex. Because signals from the
cerebral cortex arise from activities of cognitive
function (such as thought, memory, and emotion),
their influence on the appetite center is
within conscious control.