Infants Score Higher on IQ Tests If Breast Fed Exclusively
National Institute of Child Health & Human Development
infants who are born small score an average of 11 points higher
on IQ tests if they are exclusively breastfed for the first six
months of life compared to those who are given formula or solids
early on, according to findings published in the March Acta Paediatrica.
The study was conducted by researchers at the National Institute
of Child Health and Human Development (NICHD) and the Norwegian
University of Science and Technology.
study is consistent with earlier reports that full-term infants
who were of normal size for their age scored 3 points higher on
IQ tests at five years of age when breastfed exclusively for the
first six months than did infants who either stopped breastfeeding
before six months or had supplements such as formula or solids introduced
into their diets.
finding also discredits the widely held belief that supplementary
feedings of formula and cereal, in addition to breast milk, will
help these smaller infants reach normal size faster than they would
on breast milk alone. Ten percent of all births in the United States
are small for gestational age (SGA) or less than six pounds when
born full term.
study provides strong evidence that exclusive breast feeding for
the first six months benefits the cognitive development of both
small and normal-size infants," said Duane Alexander, M.D.,
Director of the NICHD. "Also noteworthy is the observation
that exclusive breast feeding does not compromise growth."
to the study's principal investigator, Malla Rao, the researchers
evaluated 220 full term SGA children and 299 full-term, appropriate
for gestational age (AGA) children. The scientists conducted the
study in Norway and Sweden, because mothers in those countries exclusively
breast feed their infants for longer durations than women in the
United States. The most recent United States statistics from the
Third National Health and Nutrition Examination Survey indicate
that while only 21 percent of infants are still being exclusively
breastfed for 4 months, this percentage drops to 16 percent by six
months of age.
children were evaluated by study physicians at birth, at six weeks
of age, and at three, six, nine, and 13 months of age. At each visit,
the children's mothers were asked whether they had fed their children
formula, milk, cereal, or other solids, and the age at which such
foods were given. The researchers tested the children at 13 months
by using the Bayley Scales of Infant Development, which measure
children's motor skills and mental abilities. When the children
were five years old, the researchers tested their intelligence with
a Norwegian version of the Wechsler Preschool and Primary Scales
of Intelligence. This test measures children's intellectual capacity,
rating how well they perform on various verbal and nonverbal tasks.
the time the infants were 24 weeks old, the researchers could find
no evidence that supplements had increased the growth of either
SGA or AGA infants. However, the researchers did find that, at five
years of age, SGA children who were breastfed exclusively for the
first 24 weeks of life scored approximately 11 points higher on
the tests than did SGA children breastfed for 12 weeks.
breast feeding does not appear to hinder the growth of SGA infants,"
Mr. Rao said. "Our findings suggest that, whenever possible,
exclusive breastfeeding for the first 24 weeks of life is the method
of choice to enhance children's cognitive development."
NICHD is part of the National Institutes of Health, the biomedical
research arm of the Federal government. The Institute sponsors research
on development before and after birth; maternal, child, and family
health; reproductive biology and population issues; and medical
rehabilitation. NICHD publications, as well as information about
the Institute, are available from the NICHD website, http://www.nichd.nih.gov,
or from the NICHD Information Resource Center, 1-800-370-2943; E-mail
NICHDInformationResourceCenter@mail.nih.gov. News Release March