Breastfeeding,
why...
Hop
LT, Gross R, Giay T, Sastroamidjojo S, Schultink W, Lang
NT. Premature complementary feeding is associated with
poorer growth of Vietnamese children. J Nutr 2000;130:2683-90
Four cohorts
of newborn children, consisting of 90 infants born in
1981, 90 in 1982, 60 in 1983 and 60 in 1984, were studied
to investigate the association between premature initiation
of complementary feeding and physical growth. The weights
and heights of children were measured monthly up to 1
year, then every 3 months for year 2 and 3, and once every
6 months in year 4. Information on feeding practices and
diseases of the children was obtained by interviewing
the mothers at each home visit. All but three children
(98.6%) were breastfed. Although 87% of the mothers breastfed
their children for at least 1 year, only 3.3% of the infants
were breastfed exclusively at the age of 4 months. Partially
breastfed and weaned infants gained weight more slowly
than those exclusively or predomi-nantly breastfed. From
1 to 3 months, exclusively breastfed infants grew more
quickly in both weight and length, followed by predominantly
breastfed infants. From 3 to 6 months, exclusively breastfed
infants gained more weight compared with the other groups.
In the older period (6-12 months), exclusively and predominantly
breastfed infants grew in length more quickly than partially
breastfed and weaned groups. However, there was no difference
in weight gain among groups. Morbidity from diarrhoea
and acute respiratory infections was significantly lower
for the 3 or more months exclusively breastfed group.
These results show a long-term deterioration of physical
growth in infants who received premature complementary
feeding and confirm the importance of exclusive breastfeeding
for at least 3 months.
Coutsoudis
A, Pillay K, Kuhn L, Spooner E, Tsai WY, Coovadia HM;
South African Vitamin A Study Group. Method of feeding
and transmission of HIV-1 from mothers to children by
15 months of age: prospective cohort study from Durban,
South Africa. AIDS 2001;15:379-87
This paper
represents the follow-up to 15 months of the study published
by the same authors in 1999 (Lancet 1999;354:471-6), when
the infants had been observed up to age 3 months. A total
of 551 HIV-infected pregnant women had been enrolled in
a randomized trial of vitamin A. Women self-selected to
breastfeed or formula feed after being counselled. Breastfeeders
were encouraged to practice exclusive breastfeeding for
3-6 months. The probability of HIV was compared in three
groups: 157 formula-fed (never breastfed); 118 exclusively
breastfed for 3 months or more; and 276 mixed-fed. The
three feeding groups did not differ in any risk factors
for transmission, and the probability of detecting HIV
at birth was similar. The probabilities of HIV detection
remained similar among never and exclusive breastfeeders
up to 6 months (19.4%), whereas the probability among
mixed breastfeeders soon surpassed both groups, reaching
26.1%. By 15 months, the cumulative probability of HIV
infection remained lower among those who exclusively breastfed
for 3 months or more than among other feeding patterns
(24.7% vs 35.9%). The authors conclude that infants exclusively
breastfed for 3 months or more had no excess risk of HIV
infection over 6 months than those never breastfed. These
findings, if confirmed elsewhere, can influence public
health policies on feeding choices available to HIV-infected
mothers in developing countries.
Williams
C, Birch EE, Emmett PM, Northstone K. Stereoacuity
at age 3.5 y in children born full-term is associated
with prenatal and postnatal dietary factors: a report
from a population-based cohort study. Am J Clin
Nutr 2001;73:316-22
Observational
studies suggested that breastfeeding benefits the visual
development of preterm children, which has been attributed
to the presence of docosahexaenoic acid (DHA) in breastmilk.
Randomized studies showed that preterm children require
a dietary supply of DHA in the first few weeks of life
for optimal visual development, but it is unclear whether
full-term children experience similar benefits from breastmilk
or DHA supplements. The objective of this study was to
compare visual acuity at age 3.5 years in healthy, full-term
children who were breastfed and in similar children who
had not been breastfed after adjustment for socioeconomic
status and maternal diet. The results show that children
who had been breastfed for 4 months were 2.77 times more
likely to achieve high-grade stereoscopic vision than
were children who had not been breastfed. Children whose
mothers ate oily fish during pregnancy were also 1.57
times more likely to achieve high-grade stereoscopic vision
than were children whose mothers did not eat oily fish.
The authors suggest that for full-term infants, breastfeeding
is associated with enhanced stereoscopic vision at age
3.5 years, as is a maternal DHA-rich antenatal diet, irrespective
of later infant feeding practice.
Horwood
LJ, Darlow BA, Mogridge N. Breast milk feeding and
cognitive ability at 7-8 years. Arch Dis Child
Fetal Neonatal Ed 2001;84:F23-7.
280 survivors
from a national birth cohort of 413 New Zealand very low
birthweight infants born in 1986 were assessed at age
7-8 years on measures of verbal and performance intelligence
quotient (IQ). At the same time mothers were questioned
as to whether they had elected to provide expressed breastmilk
at birth and the total duration of breastmilk feeding.
Some 73% of mothers provided expressed breastmilk and
37% breastfed for four months or longer. Increasing duration
of breastmilk feeding was associated with increases in
both verbal IQ and performance IQ: children breastfed
for eight months or longer had mean verbal IQ scores that
were 10.2 points higher and performance IQ scores that
were 6.2 points higher than children who did not receive
breastmilk. These differences were substantially reduced
after control for selection factors associated with receipt
of breastmilk. Nevertheless, even after control for confounding
factors, there remained a significant association between
duration of breastmilk feeding and verbal IQ. These findings
add to a growing body of evidence to suggest that breastmilk
feeding may have small long-term benefits for child cognitive
development.
Wright
AL, Holberg CJ, Taussig LM, Martinez FD. Factors influencing
the relation of infant feeding to asthma and recurrent
wheeze in childhood. Thorax 2001;56:192-7
Is the relation
between breastfeeding and childhood asthma altered by
the presence of maternal asthma? Healthy non-selected
newborn infants (n=1246) were enrolled at birth to investigate
this hypothesis. Asthma was defined as a physician diagnosis
of asthma plus asthma symptoms reported on at least 2
questionnaires at 6, 9, 11 or 13 years. Recurrent wheeze
(4 or more episodes in the past year) was reported by
questionnaire at seven ages in the first 13 years of life.
Duration of exclusive breastfeeding was based on prospective
physician reports or parental questionnaires completed
at 18 months. Atopy (a skin manifestation of allergy,
considered part of asthma syndrome) was assessed by skin
test responses at the age of 6 years. The relationship
between breastfeeding, asthma, and wheeze differed with
the presence or absence of maternal asthma and atopy in
the child. Children with asthmatic mothers were almost
9 times more likely to have asthma if they had been exclusively
breastfed. This relationship was only evident for atopic
children. In contrast, the relation between recurrent
wheeze and breastfeeding was age dependent. In the first
2 years of life, exclusive breastfeeding was associated
with about 50% lower rates of recurrent wheeze, regardless
of the presence or absence of maternal asthma or atopy
in the child.
Romieu
I, Werneck G, Ruiz Velasco S, White M, Hernandez M. Breastfeeding
and asthma among Brazilian children. J Asthma 2000;37:575-83
The authors
examined the association of breastfeeding and the presence
of chronic respiratory symptoms among 5,182 Brazilian
schoolchildren 7-14 years of age. The prevalence of medically
diagnosed asthma and current wheeze were respectively
4.6% and 11.9%. 90% of the mothers had breastfed their
child. Differently from the previous study (Wright et
al.) no exclusive breasfeeding was reported. Children
who had not been breastfed were more likely to have a
medical diagnosis of asthma, experience current wheeze,
and wheeze after exercise, than children who had been
breastfed for more than 6 months. This effect was only
present among children with no family history of asthma.
The low prevalence of asthma and wheeze observed in this
population may be partly related to the high level of
breastfeeding.
Bener
A, Denic S, Galadari S. Longer breastfeeding and protection
against childhood leukaemia and lymphomas. Eur
J Cancer 2001;37:234-8
The authors
investigated the role of breastfeeding in protecting against
childhood acute leukaemia and lymphomas in a case-control
study comprising 117 patients, aged 2-14 years, with acute
lymphocytic leukaemia, Hodgkin's and non-Hodgkin's lymphoma,
as well as 117 controls matched for age, sex and ethnicity.
The median duration of breastfeeding among patients was
significantly shorter than among controls: 7 (range 0-23)
and 10 (range 0-20) months, respectively. Breastfeeding
of 0-6 months' duration, when compared with feeding of
longer than 6 months, was associated with increased risk
for acute leukaemia and Hodgkin's and non-Hodgkin's lymphomas
(2.47, 3.75, and 4.06 times, respectively). In multivariate
analysis, breastfeeding duration continues to be an independent
predictor of lymphoid malignancies. In conclusion, breastfeeding
lasting longer than 6 months may protect against childhood
acute leukaemia and lymphomas.
Jones
G, Riley M, Dwyer T. Breastfeeding in early life and
bone mass in prepubertal children: a longitudinal study.
Osteoporos Int 2000;11:146-52
The aim of
this study was to determine whether breastfeeding in early
life is associated with bone mass in 330 8-year-old male
and female children from Southern Tasmania, representing
47% of those who originally took part in a birth cohort
study of risk factors for Sudden Infant Death Syndrome
(Lancet 1991;337:1244-7; N Engl J Med 1993;329:377-82;
JAMA 1995;273:783-9). Breastfeeding intention and habit
were assessed in both 1988 and 1996. Bone mineral density
was measured by X-ray densitometry. Children who were
breastfed had higher bone mineral density at the femoral
neck, lumbar spine and total body compared with those
who were bottle-fed. This association with breastfeeding
was present in children born at term but not those born
preterm, and remained significant after adjustment for
size, lifestyle factors and socioeconomic factors. Breastfeeding
for less than 3 months was not associated with increased
bone mass at any site. In conclusion, this study has demonstrated
a beneficial association between breastfeeding in early
life and bone mass in 8-year-old children born at term,
particularly those breastfed for 3 months or longer, which
appears biological. If this association is confirmed in
other populations and persists until the attainment of
peak bone mass, then the implication would be that osteoporosis
prevention programmes need to start very early in life.
Leeson
CP, Kattenhorn M, Deanfield JE, Lucas A. Duration of
breast feeding and arterial distensibility in early adult
life: population based study. BMJ 2001;322:643-7
This study
tested the hypothesis that duration of breastfeeding is
related to changes in vascular function relevant to the
development of cardiovascular disease. Participants were
331 adults (171 women, 160 men) aged between 20 and 28
years, born in Cambridge Maternity Hospital, UK. The distensibility
of the brachial artery was measured against type and duration
of infant feeding determined by a retrospective questionnaire.
The results showed that the longer the period of breastfeeding
the less distensible the artery wall was in early adult
life. The vascular changes observed were not explained
by alterations in plasma cholesterol concentration in
adult life. Participants, however, were self-selected
and there might have been other infant feeding factors
associated with the outcome that were not detected by
the retrospective questionnaire. In addition, there is
no evidence of an association between distensibility of
the brachial artery and subsequent development of cardiovascular
disease. To conclude, the possible causal relationship
between breastfeeding in infancy and increased risk of
cardiovascular disease is not demonstrated and these data
should not alter current recommendations in favour of
breastfeeding.
Singhal
A, Cole TJ, Lucas A. Early nutrition in preterm infants
and later blood pressure: two cohorts after randomised
trials. Lancet 2001;357:413-9
The research
group that published the previous article reported also
the follow up to 13-16 years of a cohort of 926 children
who were born prematurely and had participated at birth
in two parallel randomised trials in five neonatal units
in the UK. The same children had been studied before for
other outcomes (Arch Dis Child 1984;59:722-30; BMJ 1990;300:837-40;
Lancet 1992;339:261-4; BMJ 1998;317:1481-7). The mean
arterial blood pressure at age 13-16 years was lower in
the 66 children assigned banked breastmilk (alone or in
addition to mother's milk) than in the 64 assigned preterm
formula (81.9 vs 86.1 mm Hg). No differences were found
in the term formula (n=44) vs preterm formula (n=42) comparison.
The children followed up at age 13-16 years were similar
to those not followed up in terms of social class and
anthropometry at birth. Breastmilk consumption was associated
with lower later blood pressure, a protective factor for
cardiovascular disease. The data provide experimental
evidence of programming of a cardiovascular risk factor
by early diet and further support the long-term beneficial
effects of breastmilk.
Zheng
T, Duan L, Liu Y, Zhang B, Wang Y, Chen Y, Zhang Y, Owens
PH. Lactation reduces breast cancer risk in Shandong
Province, China. Am J Epidemiol 2000;152:1129-35
The authors
conducted a hospital-based case-control study in Shandong
Province, China, in 1997-1999. A total of 404 cases and
an equal number of controls were included. Detailed information
regarding lactation, menstruation, and reproduction was
collected through in-person interviews. The authors found
a significant inverse association between duration of
lactation and breast cancer risk. For women who breastfed
for more than 24 months per child, the risk was about
50% lower when compared with those who breastfed for 1-6
months per child. A significantly reduced risk of breast
cancer was also found for those whose lifetime duration
of lactation totaled 73-108 months and for those who breastfed
for 109 or more months. Further stratification by menopausal
status resulted in the same conclusion. These data suggest
that prolonged lactation reduces breast cancer risk.
Chang-Claude
J, Eby N, Kiechle M, Bastert G, Becher H. Breastfeeding
and breast cancer risk by age 50 among women in Germany.
Cancer Causes Control 2000;11:687-95
The authors
report the results of a population-based case control
family study of breast cancer among women diagnosed by
the age of 50, conducted in two geographic areas in Germany,
to evaluate the effect of breastfeeding on risk of breast
cancer. Among parous women (553 cases, 1,094 age-matched
controls), having ever breastfed a child for at least
1 month did not confer protection. However, risk of breast
cancer significantly decreased with increasing duration
of breastfeeding and the estimated risk was 40% lower
for 13-24 months of cumulative breastfeeding and 50% lower
for 25 months or more. These results support a protective
role of prolonged breastfeeding against the development
of breast cancer in predominantly premenopausal women.
< PREVIOUS
| NEXT >
The optimal
duration of exclusive breastfeeding * Breastfeeding, why ? * Breastfeeding, how ?
|
