JAMA: Breastfeeding for six months or longer was associated with a lower
risk of childhood leukemia compared with children who were never
breastfed or who were breastfed for a shorter time, according to an
article published online by JAMA Pediatrics. Leukemia is the most common childhood cancer and accounts for about
30 percent of all childhood cancers. Still, little is known about its
cause. Breast milk is meant to exclusively supply all the nutritional
needs of infants and current recommendations include exclusively
breastfeeding for the first six months of life to optimize growth,
development and health.
Efrat L. Amitay, Ph.D., M.P.H., and Lital Keinan-Boker, M.D., Ph.D.,
M.P.H., of the University of Haifa, Israel, reviewed the evidence in 18
studies on the association between breastfeeding and childhood leukemia.
In a review of all 18 studies, the authors found breastfeeding for
six months or longer was associated with a 19 percent lower risk
compared with no breastfeeding or breastfeeding for a shorter period of
time. A separate analysis of 15 studies found that ever being breastfed
compared with never being breastfed was associated with an 11 percent
lower risk of childhood leukemia.
The authors suggest several biological mechanisms of breast milk may
explain their results, including that breast milk contains many
immunologically active components and anti-inflammatory defense
mechanisms that influence the development of an infant’s immune system.
“Because the primary goal of public health is prevention of
morbidity, health care professionals should be taught the potential
health benefits of breastfeeding and given tools to assist mothers with
breastfeeding, whether themselves or with referrals to others who can
help. The many potential preventive health benefits of breastfeeding
should also be communicated openly to the general public, not only to
mothers, so breastfeeding can be more socially accepted and facilitated.
In addition, more high-quality studies are needed to clarify the
biological mechanisms underlying this association between breastfeeding
and lower childhood leukemia morbidity,” the study concludes.