Hello

My name is Stephanie Lang and I am a junior nursing student at the
University of North Dakota.  I am currently taking a childbearing class and
doing a clinical rotation in the OB.  I have joined the listserv because I
am interested in breastfeeding and the effects that it can have on the
body.  When I was doing some research I found conflicting articles about
the effects of breasfeeding and the incidence of rheumatoid arthritis.

One study showed that rheumatoid arthritis (RA) is three times more likely
to occur in women than men.  This is due to the hormonal differences
between the sexes.  There also evidence that women who are on oral
contraceptives have a decreased risk of RA, but women who breastfed are
more prone to RA.  Women who are on oral contraceptives have higher
estrogen levels, which have been shown to suppress prolactin.  This affect
is thought to postpone RA.  In women who breastfed, estrogen levels are
decreased.  So the prolactin that is produced during breastfeeding is not
suppressed, which would increase the risk of RA (Brennan, Ollier,
Worthington, Hajeer, & Silman, 1996).

Another study agreed that the postpartum period and breastfeeding increased
the mother's risk of RA because of the excess prolactin.  Prolactin is a
hormone with a pro-inflammatory effect, which would explain why there is an
increased risk in these patients (Silman & Pearson, 2002).

But there have been studies that have shown that breastfeeding reduces the
risk of developing RA.  One study showed that women who breastfed for 24
months or more, are 50% less likely to develop RA.  This study also found
that the high levels of estradiol and progesterone during pregnancy also
decreased the incidence of RA.  The researchers felt that the prolonged
effects or progesterone play an important role to decrease the risk of RA
because of its anti-inflammatory effect (Karlson, Mandl, Hankinson, &
Grodstein, 2004).

My Questions:  What have you heard about breastfeeding and reducing or
increasing the risks of RA?  What do you think causes the increase or
decrease?

Thank you,
Stephanie Lang, SN

Brennan, P., Ollier, B., Worthington, J., Hajeer, A., & Silman, A. (1996).

    Are both genetic and reproductive associations with rheumatoid

    arthritis linked to prolactin? Lancet. 348(9020), 106.

Karlson, E. W., Mandl, L. A., Hankinson, S. E., & Grodstein, F. (2004,

    Nov.). Do breastfeeding and other reproductive factors influence future

    risk of rheumatoid arthritis? Arthritis & Rheumatism. 50(11), 3458-

    3467).

Silman, A. J. & Pearson, J. E. (2002). Epidemiology nad genetics of

    rheumatoid arthritis. Arthritis Research. 4(3), 265-272.

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