Volume 2, 2001

Inside this issue:
	Breastfeeding 'remodels' mom's bones
	Study traces roots of obesity in Hispanic children
	New Resource: Your child's weight
	Daughters follow mom's lead when choosing beverages
	CNRC expert 'D'-mystifies nutritional rickets
	Q&A: How can I tell how much calcium is in the food I buy?
	May Teleconference

Breastfeeding remodels mom's bones

New mothers who choose to breastfeed not only help their babies. They could also be building healthier bones for themselves, according to a two-year CNRC study.

"Lactation triggers bone loss in areas prone to fractures later in life, such as the hip, wrist, and spine," said Dr. Judy Hopkinson, a CNRC lactation physiologist and a Baylor associate professor of pediatrics. "However according to our study, this 'lost' bone is completely replaced with fresh, new bone within two years of delivery."

According to Hopkinson, this bone-loss/bone-recovery cycle, or remodeling, provides a breastfeeding mother’s body a unique opportunity to repair tiny flaws, or microfractures, when the replacement bone is built. Microfractures are thought to contribute to osteoporosis fractures later in life.

Earlier research questioning whether breastfeeding is the best option for women with osteoporosis risk concerns prompted the study.

"We wondered whether women really had to choose between what's best for their babies and what's best for their bones," Hopkinson said. "Our findings suggest this is not the case."

Hopkinson monitored the bone densities of 76 new mothers over a period of two years post delivery. Half breastfed their infants, the others chose to formula-feed. Bone densities were measured at regular intervals using a sensitive bone scan called DXA. The DXA scan can detect small changes in the densitities of specific bones and bone regions, as well as the entire skeleton.

Perhaps not surprisingly, bone loss was only found in breastfeeding mothers. However, in addition to finding complete bone recovery by two years postpartum, Hopkinson also found that mothers who had breastfed for nine months or less had nearly three percent more bone than right after delivery. Mothers who breastfed longer, between 10 and 24 months, were also gaining more bone, but at a slower rate. Hopkinson believes that if the study had been longer, significant bone gains would have been found in this group as well.

During her study, Hopkinson also found that pregnancy itself appears to trigger changes in bone structure. She is investigating these findings in a new study, which monitors pre-pregnancy and postpartum bone densities to better understand how pregnancy affects maternal bone.

"How a new mother feeds her baby clearly affects where and how quickly she will deposit fresh bone, which could have an impact on her long-term bone health," Hopkinson said.

Source: Hopkinson JM, Butte NF, Ellis K, Smith EO. Lactation delays postpartum bone mineral accretion and temporarily alters its regional distribution in women. J Nutr. 2000; 130(4):777-783.