For Immediate Release July 31, 1997

     Contact: Franklin Hoke
     215-349-5659
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     University of Pennsylvania Medical Center

     Mother's Milk: Nutrition And Nurture For Infants -- And The
     Best Defense Against Disease

     From August 1 through 7, University of Pennsylvania Medical Center
physicians and other health care
     providers serving mothers and infants will join in observing the
sixth
annual World Breastfeeding Week.
     The aim of the event, sponsored by La Leche League International
and
the World Alliance for
     Breastfeeding Action, is to raise public awareness of the many
health
and other advantages of
     breastfeeding to both babies and their mothers.

     Breastfeeding is acknowledged by health professionals as the ideal
source of nutrition for infants in almost
     every case. In addition, the nurturing relationship engendered by
breastfeeding contributes to building a
     close bond between mother and child. Together, these factors
promote
the physical and emotional growth
     and development of the infant.

     Long known to be true, too, is that breast-fed babies experience
fewer
and less serious incidences of
     disease and allergy than formula-fed babies. Gastrointestinal,
respiratory, and middle-ear infections, in
     particular, are greatly reduced in breast-fed infants. In recent
years,
scientists at Penn and other institutions
     have sought to understand what it is about breast milk that makes
it so
protective for infants.

     "What researchers have discovered is that breast milk is much more
than
just food," says Charles V.
     Clevenger, MD, PhD, an assistant professor of pathology and
laboratory
medicine. "It's also a bioactive
     compound containing antibodies that defend against infection and
hormones and growth factors that direct
     the infant's immune system to develop fully and appropriately."

     For example, Clevenger's studies have shown that the hormone
prolactin,
which is responsible for growth
     and differentiation of the breast during puberty, pregnancy, and
lactation, also plays a significant role in
     stimulating immune-system cells in the infant. And while prolactin
is
primarily produced in the pituitary
     gland, Clevenger's team found that tissues in the breast are able
to
make the hormone, too.

     Clevenger notes that, in the adult stomach, the proteins that
constitute the antibodies, hormones, and
     growth factors in breast milk would not survive exposure to the
digestive acids.

     "But infants are different from adults, and one of the ways they
are
different is that their stomachs don't
     make as much acid," Clevenger says. "As a result, many of the
important
immunostimulatory proteins in
     breast milk can pass through the stomach of an infant and into the
intestine, from which they enter the
     infant's bloodstream largely intact. In the adult, these proteins
would
be destroyed."

     Investigations by other scientists have demonstrated that vaccine
responses in breast-fed infants are
     enhanced over those of formula-fed babies. One proposed mechanism
to
explain this observation is that
     certain antibodies in breast milk may mimic bacterial and viral
proteins. Such mimicry would have the effect
     of priming the infant immune system to respond more vigorously when
later exposed to actual pathogen
     proteins.

     A number of studies over the last decade have also revealed the
presence of more than a dozen cytokines
     in breast milk. Cytokines are members of a family of proteins
secreted
by various cells that stimulate,
     inhibit, or otherwise regulate immune-system cells. Many of these
may
be produced by T cells in breast
     milk itself, while others are made by cells within the breast.

     Breast milk has very high concentrations of complex carbohydrates,
and
some of these have been shown
     to have immune properties, too. Oligosaccharides and
glycoconjugates,
in particular, may inhibit infection
     by binding to pathogens at the molecular sites that they would
otherwise use to attach to and then attack
     cells in the infant. Another molecule with an antibacterial role is
lactoferrin, a protein that acts by binding
     iron in different situations. In some circumstances, lactoferrin is
also able to act as a cytokine.

     Formula-fed babies are denied many of the immune and other benefits
that accompany breastfeeding,
     according to physicians and scientists. Although there are times
when
formula is preferable to breastfeeding
     -- such as when the mother is HIV-positive but the child is not --
such
cases are rare, they say. In the great
     majority of situations, mothers should be strongly encouraged by
their
caregivers to breastfeed their infants
     and given the necessary support to enable them to succeed.

                                            ###


     The University of Pennsylvania Medical Center's sponsored research
ranks fifth in the United States, based
     on grant support from the National Institutes of Health, the
primary
funder of biomedical research in the
     nation -- $149 million in federal fiscal year 1996. In addition,
for
the second consecutive year, the
     institution posted the highest growth rate in its research activity
--
9.1 percent -- of the top ten U.S.
     academic medical centers during the same period. News releases from
the
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