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Breastfeeding and bone density change

Karen L Pearce, University of Massachusetts Amherst


Breastfeeding women experience changes to their bone mineral density over the course of lactation. The exact nature of the relationship between breastfeeding and lactation-induced change in bone density is not well understood but it is known that bone density decreases during lactational amenorrhea and increases after menses resumes. In studies that have explored the relationship between breastfeeding and bone density, variation in breastfeeding behaviors is considered 'noise' to be eliminated. This study explores this relationship by focusing on the role of breastfeeding variation on the rate of bone density change, both before and after menses resumes. To date, most research on breastfeeding and bone density has been conducted by clinical researchers. This study differs from these studies because of an anthropological approach that puts at the forefront of the analysis behavioral variation. Using a biocultural framework, the study design draws from the methods and theories from both biological and cultural anthropology. The theoretical lens, the methodologies, and the theories combine to reveal the complexities in the topic of breastfeeding and bone density. A total of 35 women participated in a six-month longitudinal assessment of bone density change during breastfeeding. They recorded all breastfeeding activity over a 24-hours period each time that their bone mineral density was measured. Results of the study showed that greater intensity of breastfeeding in the amenorrheic months significantly attenuated bone density loss in this population of U.S. women. Amenorrheic women who breastfed with less intensity showed greater decline in their bone mineral density. Similar benefits to the maternal skeleton were not demonstrated in high intensity breastfeeders after menses resumed. Furthermore, the evaluation of the breastfeeding styles of the women in this population showed them to conform to AAP breastfeeding guidelines despite their own assertions that they do not adhere to such recommendations.

Subject Area

Physical anthropology|Anatomy & physiology|Animals

Recommended Citation

Pearce, Karen L, "Breastfeeding and bone density change" (2006). Doctoral Dissertations Available from Proquest. AAI3215777.