Re Naomi Bar-Yam's thought-provoking question:
"There is a lot of concern about and research going into
contaminants in breastmilk and transfer of said contaminants
to babies.
Here's my question: contaminants are often measured in the blood.
Does anyone ask the same question about blood transfusions and
blood donations?"
While toxic contaminants do equilibrate throughout the human
body--with the roughly the same concentrations found in the lipid
fraction of blood serum as found in the lipid fraction of breast
milk--the dangers of toxic transfer is much greater for breastfeeding
infants than for the recipients of donated blood.
There are at least three reasons for this. First, blood is much
leaner than milk. Blood is less than 1/2 percent fat; human milk is
about 4 percent fat. Thus, on an ounce for ounce basis, milk
delivers (at least) an eight-fold bigger load of contaminants than
blood.
This is why babies accumulate a bigger body burden of fat-soluble
environmental contaminants (e.g. dioxin, pesticides, PCBs) from 9
months of nursing than from 9 months of in utero life. While the
daily volume of exchange across the placenta (via blood) is greater
than the daily volume of milk received after birth, the absolute
amount of toxics received is less during the prenatal period. (In
spite of this difference in quantity, the harm done from prenatal
exposures is worse than the harm created by postnatal breastmilk
exposures.)
This is also why women's own toxic body burden drops rapidly during
lactation but is affected less by a fullterm pregnancy and not at all
by regular menstruation.
Second, the quantities are vastly different in magnitude. A
150-pound adult receiving a pint or two of blood on a one-time basis
is just not receiving the same exposure as a 10 pound baby receiving
a quart of milk every day for two, three, six, twelve (or, as in our
household, 40 and counting...) months.
Third, even if exposure were similar, we'd still be vastly more
concerned about breastfeeding newborns than adult surgical patients
because babies are so much more vulnerable to the effects of toxic
exposure. Even the tiniest exposures appear to have the power to
sabotage infant development in ways that adults are not affected by.
For example, everyone over the age of 6 months has a blood-brain
barrier that works pretty well to keep neurological poisons (e.g.
insecticides) from entering the gray matter of the brain. However,
newborns don't have one. They also don't have effective detoxifying
enzymes. And of course, their bodies, minds, and immune systems are
still in the process of being assembled, so exposures very early in
life can create risks to health that are disproportionate to dose.
The new thinking in toxicology is "the timing makes the poison" (as
opposed simply to "the dose makes the poison").
Obviously, as everyone on this list knows so well, breast milk
contains many elements whose job it is to guide the assembly of body,
mind, and immunity, which is why it is the only appropriate food
source for infants. When breast milk becomes filled with
immune-suppressing, carcinogenic, I.Q.-depressing, and
hormone-disrupting chemicals, its goodness is compromised. (But NOT
to the point where it has become a worse food for babies than
formula. Yet.)
So here are my personal conclusions: The very fact that breastmilk
has no substitute is why we breastfeeding mothers and professionals
need to advocate for the idea that any toxic chemical known to
accumulate in mother's milk has no rightful place in our economy.
Finding non-toxic alternatives for each every toxic substance now
contaminating mothers milk should be a national priority. It won't
be unless we nursing mothers and breastfeeding experts demand it.
(Think of what Mothers Against Drunk Drivers did to make our highways
safer.) And the demand requires that we be unafraid of public
conversation about breast milk contamination...indeed that we seize
control of the debate and shape it. Otherwise, those who don't
understand the necessity of breastfeeding--and its delicate
psychology in a world where mothers are relentlessly propagandized by
formula companies--will use the issue of breastmilk contamination for
their own purposes without realizing that they are further
undermining the sacred communion of mother and child. In short, the
message about breastmilk contamination should be coming from us. We
shouldn't be reacting to it.
--
--
Sandra Steingraber, Ph.D.
Visiting Assistant Professor
Program on Breast Cancer and Environmental Risk Factors
110 Rice Hall
Cornell University
Ithaca, NY 14853
[log in to unmask]
www.steingraber.com
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