Breast milk content may affect child's obesity risk

Breast milk content may affect child's obesity risk
Mothers nurse their babies in Malaga, southern Spain June 30, 2007. June 30, 2007. Mothers who breast feed and have high levels of a protein secreted by lipids in their milk may be increasing the risk that their child will be overweight, German researchers report. (Jon Nazca/Reuters)NEW YORK (Reuters Health) - Mothers who breast feed andhave high levels of a protein secreted by lipids in their milkmay be increasing the risk that their child will be overweight,German researchers report.
Dr. Maria Weyermann of The German Cancer Research Center inHeidelberg and her colleagues found that a child's likelihoodof being overweight by age 2 rose with the amount ofadiponectin in his or her mother's milk.
The significance of these findings remain unclear, Dr.Matthew W. Gillman and Dr. Christos S. Mantzoros, HarvardMedical School, Boston, point out in an editorial accompanyingthe study, because infants may not be able to absorb theadiponectin contained in breast milk.
Also, they add, high levels of adiponectin in adultsactually reduce heart disease and diabetes risk, making it"counterintuitive" that high levels would contribute to excessweight in children.
The jury is still out on whether nursing does protectchildren from becoming overweight, Weyermann and her team add.
The researchers investigated how breast-feeding mightinfluence obesity risk by looking at adiponectin and anotherprotein secreted by fat cells, leptin, which regulates appetiteas well as the body's use of energy from food.
Adiponectin is involved in metabolism of fats and sugars.The fetus and placenta produce both proteins at high levels,the researchers point out, raising the possibility that theyplay a role in fetal development.
The levels of both proteins were measured in the breastmilk of the mothers of 674 children when the infants were sixweeks old. Among the children who were breast-fed for at leastsix months, obesity risk rose in tandem with breast milkadiponectin levels. However, leptin levels showed noassociation with whether or not a child would be overweight.
"Our data provide evidence that the possible protectiveeffect of breast-feeding against childhood obesity mightdepend, at least in part, on low levels of breast milkadiponectin," Weyermann and her team write.
More research is needed before it's possible to determinethe health implications of the research, if any, Gillman andMantzoros add. "The best advice remains that all women shouldstrive to breast-feed their children for at least 12 months,with the first 4- to 6- months consisting of exclusivebreast-feeding."
SOURCE: Epidemiology, November 2007.