UNDERCONSUMPTION OF PROTEIN AND HEALTH-RELATED PROBLEMS

Although protein supplies in the United Stales are plentiful,
and drastic protein deficiency is uncommon, several groups
of individuals are susceptible to insufficient intakes:

(1)elderly individuals
(2) individuals with low income
(3)strict vegetarians
(4) individuals with a lack of education or who are unwilling to shop wisely
(5) patients who are chronically ill or hospitalized (e.g.. patients with AIDS,
      anorexia nervosa, or cancer)
Fewer than 10% of U.S. adults older than 70 years of age get
less than the recommended 0.8 g/kg body weight per day.
Consumption of protein by older Americans may be related to cost,
inability to prepare nutritious meals, depression, difficulty chewing,
or concerns about the fat and cholesterol content of meats.
Inadequate amounts of dietary protein contribute to sarcopenia.
   Certain physiological conditions and impaired digestion
or absorption cause excessive protein losses and may pre-
cipitate protein-energy malnutrition (PEM). Although
PEM is uncommon in the United States, given the above-
mentioned conditions, malnutrition is frequently unrecognized.
PEM is usually accompanied by other nutritional deficiencies.
Separating the effects of different nutrient defi-
ciencies by observing clinical symptoms is often difficult.
PEM affects the whole body, including even component of
the orofacial complex.
   The occurrence of PEM during critical developmental
stages, including the prenatal and postnatal periods, may
affect developing tissues and can lead to irreversible changes
affecting oral tissues. During tooth development, mild-
to-moderate protein deficiency results in smaller molars,
significantly delayed eruption, and retardation during devel-
opment of the mandible. Smaller salivary glands result in
diminished salivary flow; this saliva is different in its protein
composition and amylase and aminopeptidase activity, com-
promising the immune function of the saliva.
   Poor nutrition results in delayed eruption and delayed
exfoliation of deciduous teeth. In addition to the increased
rate of caries in malnourished children, the peak caries expe-
rience is delayed by approximately 2 years. The increased
caries rate may simply be related to the length of time a tooth
is in the oral cavity; if the delay in exfoliation is greater than
the delay in eruption, the tooth is in the mouth a longer time,
and it is exposed to caries-producing bacteria longer. Chil-
dren with malnutrition (e.g., in developing countries and in
many urban and rural areas in developed countries) have
different dietary habits overall and oral environments that
are not conducive to dental caries. However, the teeth in
these populations are highly susceptible to dental caries.
Increased caries susceptibility may be related to alterations
in structure of tooth crowns and diminished salivary flow,
or changes in saliva composition may be related to malnutri-
tion issues.   
   Epithelium, connective tissue, and bone also may be
poorly developed. An increase in acid solubility associated
with chemical alterations of the exposed enamel surface may
contribute to increased caries susceptibility.
   The periodontium includes the hard and soft tissues sur-
rounding and supporting the teeth: gingival, alveolar mucosa,
cementum, periodontal ligament, and alveolar bone. An
insufficient intake of protein results in negative nitrogen
balance depleting nitrogen reserves, reducing blood protein
levels, and decreasing resistance of the periodontium to
infections. In addition, the ability of the periodontium to
withstand the stress of injury or surgery is reduced, and
recovery periods are longer. In malnourished children,
secretory immunoglobulin A (sIgA) levels are depressed.
sIgA is the predominant immunoglobulin, or antibody, in
oral, nasal, intestinal, and other mucosal secretions, and
provides the first line of defense in the oral cavity. Low sIgA
levels in malnourished children probably play a role in their
increased susceptibility to mucosal infections.
   PEM may be a major reason for the increased incidence
of noma and necrotizing ulcerative gingivitis (NUG), con-
ditions that are clearly associated with depressed immune
responses caused by nutritional deficiencies, stress, and
infection. Noma is u severe gangrenous process usually
manifesting as a small ulcer on the gingiva that becomes necrotic
and spreads to produce extensive destruction of the lips, cheek,
and tissues covering the jaw. NUG is characterized by erythema
(marginated redness of the mucous membranes caused by inflammation)
and necrosis (degeneration and death of the cells) of the
interdental papillae. This painful gingivitis is generally
accompanied by a metallic taste and foul oral odor. Cratered
papillae often remain after treatment of the disease.
   A scenario in which NUG occasionally occurs is in
college students who are under a great deal of psychological
stress and have poor eating habits. It also can be observed
in individuals who live in developed countries and are
severely debilitated or immunocompromised (having an
immune response that has been weakened by a disease or
pharmacological agent), or in children 2 to 6 years old who
live in developing countries, are malnourished, and have
recently experienced a stressful event, such as a viral
disease.
   NUG is possibly precipitated by emotionally stressful
situations that affect eating patterns, leading to acute defi-
ciencies, and lowering the immune response to bacteria nor-
mally found in most oral cavities. Decreased host resistance
to infection may permit gingival lesions to spread rapidly
into adjacent tissues, producing extensive necrosis and
destruction of orofacial tissues, whereas in a healthy indi-
vidual, the lesion is limited to the gingiva alone. Wound
healing is also delayed.
   In other areas of the world, where quantities of high-
quality protein and kilocalories are insufficient, PEM is
commonly seen. Kwashiorkor develops when young chil-
dren receive adequate kilocalories, but not enough high-
quality protein. It usually appears after the child
has been weaned from breast milk. Marasmus occurs in
infants when protein and kilocalories are deficient in the
diet.
   Kwashiorkor and marasmus are very serious health prob-
lems that have received much attention by the United Nations
and the WHO. Incaparina, a food powder made from corn,
cottonseed, and sorghum with mineral and vitamin supple-
ments; skim milk powder; and the addition of lysine to
cereal products have been used to improve nutritional status
in developing countries. However, most of these efforts to
improve the status of nutrition worldwide have not been well
accepted for various reasons, and the protein-energy prob-
lems in the world still exist.

Nutritional Directions

  • Suggestion Meals-on-Wheels or community senior centers for
    older people with an inadequate diet.
     
  • Suggestion for supplementation of protein content of the diet by
    adding skim milk powder to milk, soups, or mashed potatoes
    (if the person is not lactose intolerant) and by adding cheese
    to foods.