Breastfeeding and Bone Health

Breastfeeding and Bone Health

It’s a commonly held belief that women who breastfeed their babies experience bone loss at a much greater rate than women who do not breastfeed. Not only that, but the longer you breastfeed, the worse the bone loss will be. That somehow, if we feed our baby in a way that’s biologically normal, there will be devastating consequences to our bodies. It’s never made sense to me that nature’s system for nourishing our young could lead to such devastating consequences as osteoporosis and fragile bones.

It turns out that all those old wives’ tales were wrong. At least according to some recent research.

A study published in 2011 asked the following questions:

  • How does long-term breastfeeding affect a woman’s bone health?
  • Are there differences in bone mineral density, strength or size among women who breastfed for varying amounts of time?
  • Is there a relationship between cumulative breastfeeding and bone condition?

145 women participated in the study. Their children’s ages ranged from 16-20 years. Cumulative duration of breastfeeding was classified as short (<12 mo), medium (13-20 mo), long (21-32 mo) and very long (>33mo). The women in the long and very long groups tended to have more children than in the short and medium groups.

Here are the results:

  • Whole body bone area, mineral density and mineral content did not differ between groups.
  • Women whose cumulative breastfeeding duration was at least 33 months had greater hip strength and tibial strength than women who breastfed a shorter time.
  • Very long breastfeeding duration resulted in larger bone size.
  • No differences were noted between women who exclusively breastfed vs. partially breastfed.
  • High levels of estrogen inhibit formation of some types of bone tissue. It is thought that the low estrogen levels during lactation encourage bone expansion, resulting in increased bone mass. That is why those women who breastfed longer than 33 months built up larger and stronger bones.

This is great news! Another indicator that our bodies were made to breastfeed for many months or years. So keep it up! Even if you can’t exclusively breastfeed your baby, you will be making your baby and your body stronger every day!

(Note: This research did not address the effects of pumping.)