Judy:  I wasn't the original poster, but just try to keep me from adding
my 2 cents on something I care about...My understanding of the osteoporosis
research (and there is a mounting body of evidence, not just ONE study) is
that the bone building capacity accelerates to the point where a woman is
laying down new bone at the rate of an adolescent.  At this point, her
calcium, magnesium and vit D consumption is very critical to this new bone
growth.  The number of times this process is triggered would be an
important feature in long-term bone densisty.  Now, the theory is that the
length of lactation IS important in the triggering the intensity of bone
development, but that there is a point where no greater gains are made. So,
the longer you bf, the more intense bone building occurs (up to a point).
If women bf until their menses return (on average 14.2 months for ecologic
nursing), then the process begins then and very intensely.  If they wean
before this and their menses have not yet returned, the process begins when
their menses return.  If their menses return early (before 14 m)  and they
wean early-say at 3-4 months--(prematurely, IMHO), the bone growth occurs
after weaning.  However, in women whose menses return early, we must
question the hormonal levels that are responsible for this process.
        Some women menstruate early because they are not bf on demand
(ecologic bf), sleeping with their babies, or are using lots of artifical
nipples.  Other women do practice ecologic bf, yet have large quantities of
stored estrogen in the form of adipose tissue (and this may cause their
menses to return earlier--no one is quite sure though).  We do not know
much about what happens in these women.  We do know that heavier women are
at lower risk of osteoporosis overall (whether this is an estrogen thing or
a weight bearing exercise thing...who knows?)  The women I'm concerned
about are the ones who have early return of menses because of non-ecologic
bf.  I suspect that the positive health effects of bf are lower for these
women because their hormonal levels are quite different than the ecologic
bf'ers in the first 6 months post-partum.
        Have I confused anyone yet?  This should cause any researchers out
there to run to do more research.  There is still so much to learn in this
area.  If the health of babies isn't enough to make bf the norm, maybe the
long-term health of women (and possible savings in health care costs) will
spark interest.

: )Chris Hafner-Eaton, PhD, MPH, CHES, IBCLC  email: [log in to unmask]   : )
: )HSR & Health Educational Consultant        voice/fax: 541 753 7340    : )
: )LLLLLLLLLLLLL**CHANGE THE WORLD, NURTURE A CHILD!**LLLLLLLLLLLLLLLLLL : )