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Moderate
Exercise OK for Breast-Feeding Moms
New moms can stop worrying: Thirty minutes on a treadmill
won't deprive your baby of essential ingredients in your
breast milk.
A study published in a past issue of Pediatrics concludes
that moderate exercise doesn't affect levels of three key
immunity-building components in breast milk.
Researchers at the University of North Carolina at Greensboro
say the findings should ease concerns among women that arose
after a widely publicized 1998 study warned that strenuous
exercise reduced a vital antibody in breast milk.
"The popular press really picked up on that study,"
says Cheryl A. Lovelady, author of the new study. "Whenever
I'd go to speak on exercise, people would say, 'What about
the antibodies?' "
The 1998 study, by Indiana University researchers, had reported
that tests of breast milk 10 minutes and 30 minutes after
a mother exercised heavily showed significant reductions
in immunoglobulin A (IgA), which protects against viruses
and bacteria.
However, that study found IgA levels rebounded to nearly
normal levels an hour after exercise.
The North Carolina researchers say the 1998 study results
had been based on IgA tests given after the women "exercised
until exhaustion."
By contrast, the new study tested levels of IgA and other
beneficial substances in breast milk after moderate exercise
-- and yielded unequivocal results.
"The most important conclusion is moms can embark on
a moderate exercise program and not be concerned about it
affecting the composition of their breast milk," Lovelady
says.
In the latest study, 17 women who were regular exercisers
gave samples of their breast milk before a workout. They
then completed moderate, 30-minute sessions on a treadmill
-- at about 75 percent of maximum heart rate -- and gave
breast milk samples 10 minutes and 60 minutes later.
The exercise did not affect levels of IgA or two key bacteria-fighters:
the protein lactoferrin and the enzyme lysozyme. In addition,
concentrations of the three compounds were similar in the
breast milk of the women who exercised regularly and a control
group of sedentary women.
Researchers measured these three compounds because they're
among the most important among 200 in breast milk and they
appear in large enough concentrations to measure, says Lovelady,
an associate professor of nutrition.
The study did not look at the effects of more strenuous
exercise. "We still don't know about extreme exercise,
so that's not what we recommend," Lovelady says.
Moderate exercise, she says, improves the mother's cardiovascular
system and immune system, among other things. However, too
much or too little exercise can lower immune system function,
she adds.
Lovelady stresses the importance of a well-balanced diet
among breast-feeding women. And she recommends those not
in the habit of exercising wait at least a month after giving
birth to start exercise, and then they should begin gradually.
Dr. Lawrence M. Gartner, chairman of the executive committee
of the breast-feeding section of the American Academy of
Pediatrics, says the study's findings reinforce his belief
in the value of moderate exercise for nursing mothers.
"I did not think moderate exercise had any detrimental
effect on any aspect of breast-feeding," Gartner says.
However, like Lovelady, he adds the effects of extreme exercise
on breast-feeding remain uncertain.
The study's results should come as welcome news to many
women, at a time when breast-feeding has reached a record
high in the United States.
More women are starting to breast-feed soon after giving
birth and more are continuing to nurse their infants to
six months of age, according to a recent survey by the Ross
Products division of Abbott Laboratories, a maker of infant
formula.
About seven of 10 new mothers started breast-feeding in
2001, and about one-third continued to nurse at six months
-- the highest percentages documented by the company since
it started surveying breast-feeding practices in 1954.
For more on breast-feeding, visit the La
Leche League International.
Article Source: HealthDay
Article Author: Gary Gately
Net Reference 101
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