Breastfeeding May Lower
Childhood Leukemia Risk
Breastfeeding for even a few months
may lower the odds that a child will develop leukemia, a new research
The analysis of 14 studies conducted
since 1988 found that overall, longer-term breastfeeding was linked
to a 24 percent lower risk of acute lymphoblastic leukemia (ALL),
the most common form of childhood leukemia. Breastfeeding for
6 months or less appeared to reduce ALL risk by 12 percent.
Breastfeeding was also linked to
a lower risk of acute myeloblastic leukemia (AML), a form of the
cancer that in recent decades has accounted for 16 percent of
leukemia cases among U.S. children.
Leukemia is a disease in which
the bone marrow produces large numbers of abnormal, immature white
blood cells, crowding out normal blood cells over time. The core
difference between ALL and AML is in the type of white blood cell
In the past, individual studies
have yielded conflicting results on whether breastfeeding affects
children's leukemia risk. But the new findings, based on international
studies including more than 8,000 children with ALL or AML, offer
a "strong suggestion" that breastfeeding is protective, Dr. Marilyn
Kwan of the University of California, Berkeley, stated.
She and her colleagues report the
findings in the current issue of the journal Public Health Reports.
Breastfeeding is known to have
a number of health benefits, including a lower risk of common
childhood infections. It's this particular benefit, according
to Kwan, that may explain the connection between breastfeeding
and lower leukemia risk.
Other researchers have theorized
that a rare, abnormal immune response to early-life infection
may play a role in ALL. In children with genetic aberrations that
predispose them to the disease, such an abnormal immune response
could act as a "secondary promoting event" that results in ALL,
Breastfeeding, through its benefits
for the developing immune system, may protect against such an
The finding that breastfeeding
was also related to a lower risk of AML was "not anticipated on
biological grounds," the researchers note in the report.
It's possible, Kwan said, that
a separate immune-based mechanism underlies this relationship,
but more research is needed to answer that question.
Although leukemia is the most common
childhood cancer in the U.S., it is relatively rare for children
to develop cancer. And Kwan cautioned that women who cannot breastfeed
should not worry they are putting their children at greater cancer
Instead, she said, this study suggests
that lower leukemia risk might be something to "add to the list"
of the potential benefits of breastfeeding.
SOURCE: Public Health Reports,
Reference Source 89
November 11, 2004