As a breastfeeding mother– one who nursed well into my child’s toddler years– I was alarmed when I first saw the 2010 Reuters article, “Duration Breast-feeding Linked to Osteoporosis Risk.” The author reported on a recent study in Mexico, which examined the relationship between breastfeeding and osteoporosis.
According to Reuters, the authors of the study concluded that women who nurse practice “extended” breastfeeding are at a higher risk of developing osteoporosis– a potentially serious condition involving thinning of the bones. This is one very rare case in which breastfeeding appears to be detrimental to the health of the mother.
But, before you abruptly wean your toddler or panic about your impending doom, let’s re-examine the facts. I believe, based on the current bulk of scientific evidence, that there is no relationship between extended breastfeeding and osteoporosis. In fact, I’m fairly confident that extended breastfeeding actually prevents the condition.
Pregnancy, Breastfeeding and Bones
In any scientific situation, a small-scale study may yield inaccurate findings. For this reason, we can’t take the recent study of extended breastfeeding and osteoporosis at face value– especially since it contradicts decades of solid scientific evidence.
Current science tells us this: All women experience some degree of temporary osteoporisis a few months after giving birth. This occurs regardless of whether a woman nurses or formula-feeds, and regardless of the amount of calcium, magnesium or vitamin D in her diet. For some women, the temporary osteoporosis persists for weeks or months following the child’s birth. Breastfeeding women tend to experience a longer period of osteoporosis than mothers who do not breastfeed.
However, most women are restored to their normal bone mass 12 months after giving birth–even if they are still nursing. For those who still have thinner-than-usual bones, the temporary osteoporosis may persist throughout the duration of breastfeeding.
But the Good News Is…
Most studies reveal that, after weaning– whether that takes place at 6 months or 40 months–mothers experience an increase in bone density. Their bones are stronger and thicker than those of formula-feeding moms. This means fewer fractures in our pre-menopausal years and, possibly, a lower osteoporosis risk in our post-menopausal years.
No one is quite sure why this happens, but studies to date have indicated that lactating women do not lose as much calcium in their urine as mothers who do not breastfeed. It could also relate directly to the changes in estrogen and progesterone that occur during lactation and during weaning.
All studies until 2010 have found that women who breastfeed for 6, 12 or 22 months have similar or superior bone densities to women who have not been pregnant and have not breastfed. So far, evidence has suggested that women who have breastfed have lower rates of osteoporosis after menopause. In fact, one study indicates that nursing until age two can decrease your osteoporosis risk by up to 500%. Calcium supplementation is not necessary to make this happen.
A Flawed Study?
The recent study suggesting a link between extended breastfeeding and osteoporosis is weak and full of holes. It contradicts the findings of decades of solid scientific investigations, but many pediatricians and women’s health experts may take it at face value– to the detriment of nursing mothers and their children.
Only 29 of the post-menopausal women involved in the study suffered from osteoporosis. Very few of them had nursed their children beyond 36 months of age, but, since it was a common thread in the few women questioned, the authors of the study ran with the conclusion that it was the cause of their ailment.
However, anyone who has taken a simple logic clas understands that correlation does not imply causation. If you were to interview 29 other women with osteoporosis, you may find entirely different results. Only a very large-scale study, interviewing tens of thousands of osteoporitic women about their diets, body-types, family histories, lifestyles, pregnancies, and breastfeeding history, could accurately determine a link. A tiny survey of 29 elderly women will yield no conclusive results.
The Bottom Line
To date, all well-designed studies have indicated that breastfeeding lowers a mother’s risk of osteoporosis and dozens of other conditions. There is no reason to discredit decades of research because of one small and poorly-designed study.
Although I did not nurse my daughter until age 3, like some mothers, I do support women who choose to nurse for 36 months or more. It’s good for you and it’s good for your child, so, as long as you both enjoy it, rock on– and don’t fear bone loss as a result.
Reuters- Duration Breast-Feeding Linked to Osteoporosis Risk
Katherine Orlinsky- Osteoporosis and Breastfeeding