The Corpus Callosum

I’m sitting here, wondering why in the world I wrote so much about a
topic that is of no more than passing interest to me.  Perhaps
if I keep writing, I will figure it out.

Note: this will not make much sense unless you’ve already read Janet’s
more recent post on the topic of breastfeeding, here: href="http://scienceblogs.com/ethicsandscience/2006/06/what_are_the_real_benefits_of.php">What
are the real benefits of breastfeeding? Statisticians weigh in
.
 You also have to have read the main article she cites, here: href="http://www.stats.org/stories/breast_feed_nyt_jun_20_06.htm">What
Science Really Says About the Benefits of Breast-Feeding (and what the
New York Times didn’t tell you).

This is the comment I left:

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OK, I’ve read the article by Goldin et. al.,
and I have a few comments.  First of all, I am not a
statistician, and I habitually get in the back seat when a statistician
speaks about research.  However, I am not happy with the depth
of their analysis.  

First, in order to make a pronouncement about the entirety of the
literature on a subject, one would have to gather all the relevant
articles and read them.  I do not see any evidence that they
have done so.  One would have to rank the studies in terms of
quality.  The date of the study is one factor, but it is not
really a measure of quality.  Maybe they did all that, and did
not tell us, but I don’t think we can be confident in their conclusions
without knowing.

Second, I have to give them credit for finding evidence that some of
the people involved in this might be biased.  That is
important to know.  But it is circumstantial, and does not
really help us get to the truth of the matter.  It only
cautions us to look more closely at the research methods.

Furthermore, their own article is not free of evidence of
bias.  For example, they write rather dismissively about the
seriousness of the illnesses: “if the only adverse consequence of not
nursing is that babies get a few more colds…”  They do not
mention  rel="tag">necrotizing enterocolitis, which has a
significant mortality rate.  [See especially: Lucas A, Cole
TJ: Breast milk and neonatal necrotising enterocolitis. Lancet
1990 Dec 22-29; 336(8730): 1519-23.]

Finally, they conclude with this:

Our lives are filled with risks, small and large. Not
nursing is a small risk, the real question is what it costs (or
benefits) you.

That is true.  However, consider that every single person on
the planet has either been breastfed, or not.  That being the
case, whatever risk you find, no matter how small, has to be multiplied
by six billion.  Take a small number and multiply by six
billion, and the product just might turn
out to be significant.  

The authors point out, correctly, that a full analysis of the topic
would be highly complex.  They are critical of the AAP for
being too casual in their analysis.  Then they toss another
casual analysis on the heap.  

Perhaps they are correct in saying that an important public health
announcement should have a stronger scientific basis.  But it
would be more helpful if they would go on to say how the science could
be strengthened, e.g. by a Cochrane review of the existing data…

…and, as it turns out,  href="http://www.cochrane.org/reviews/en/ab003517.html">there
is a Cochrane review that is pertinent, albeit not
comprehensive; it only examines a narrow piece of the overall
question.  Among their conclusions:

Infants who are exclusively breastfed for six months
experience less morbidity from gastrointestinal infection than those
who are mixed breastfed as of three or four months, and no deficits
have been demonstrated in growth among infants from either developing
or developed countries who are exclusively breastfed for six months or
longer.   

If a careful review of 2,668 unique citations leads to a conclusion
that exclusively-breastfed infants do better, then I think we need to
pay attention.  Granted, it is not a comprehensive analysis,
but it also is not “just a throw back public health campaign based on
voodoo science.”

I’ll agree with them that some of the studies cited in the New
York Times
are insufficiently rigorous.  But if what
we are trying to do is get a fair and balanced look, then let’s take a
look at the studies that are rigorous.

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Let us also note that the WHO has been looking at this issue very
closely, and at least mention the fact that they have consistently come
out in favor of breastfeeding.  Granted, the WHO is not a
scientific agency; it is a political organization.  Whatever
their agenda, though, at least it is not an economic one.  As
far as I can tell, their motivations are purely humanitarian.
 That is not the case with some of those who have a say in
this. From a WHO publication, href="http://www.who.int/nutrition/publications/evidence_ten_step_eng.pdf">Evidence
for the Ten Steps to Successful Breastfeeding (link opens
PDF):  

Reiff & Essock-Vitale (1985) reported a
survey in a university hospital in the United States of America (USA)
where most official policies, educational materials and counselling and
support programmes promoted breastfeeding. However, there was no policy
to limit the use of infant formula, and a single brand of ready-to-use
infant formula was used daily in the maternity ward. In the delivery
room 66% of mothers had stated a preference for exclusive breastfeeding
but when interviewed at 2 weeks only 23% were breastfeeding without
formula supplements.  93% of the mothers using formula at 2
weeks knew the name of the hospital brand and 88% were using it.

But I think what really interests me about this topic is something that
is not immediately obvious.  The authors of the
Goldin et. al. paper wonder if the campaign
to increase the frequency of breastfeeding is “just a throw back public
health campaign based on voodoo science.”  

That question raises an issue that I think deserves some attention: how
much evidence do we need regarding the health effects of a given
intervention, before it is worth having a government-sponsored ad
campaign?

Clearly, since breastfeeding affects a large number of people, even a
small health benefit could have a highly significant impact.
 Equally clearly, if we wait until the evidence is
incontrovertible, we potentially loose an opportunity to have a large,
positive impact.  Goldin et. al.
entirely miss the point with their closing sentence:

Our lives are filled with risks, small and large. Not
nursing is a
small risk, the real question is what it costs (or benefits) you.

No no no.  A public health campaign is NOT about what benefits
a given individual.  That is a question that only the
individual can decide.  I am not disputing anyone’s right and
responsibility
to make an independent choice.  But
that is not the point at all, when it comes to public health.
 The point of public health is to improve the average health
of the population.  Yes, some people may be inconvenienced;
some may even face serious risks.  

This is not a new argument.  The same point has been debated ad
nauseam
with regard to vaccinations.  Vaccinations
can — and do — result in serious problems, including death.
 But we routinely ask people to accept a small risk of death
from the vaccine, in exchange for improved health of the population.
 Sometimes we make mistakes, as was the case with the swine
flu vaccination program in the 1970′s.  But the alternative is
no vaccinations, since we do not know and can not know,
ahead of time, which programs will turn out to have been worthwhile.
 

There is an ethical question with regard to public health campaigns.
 That question is the one that is at the root of ALL ethical
questions: who gets to make the decision?
 In the case of vaccination, a case can be made for compulsory
vaccination, if the evidence is strong enough.  If the
evidence is less strong, then compulsion is not justified, but
influence may be justified.  

The government campaign to promote breastfeeding is not intended to
force anyone to do anything.  It is intended to have an
influence on the behavior of a proportion of the population.
 So this is not really an ethical issue, so much as it is a
policy issue: does it make good economic sense to promote a behavior
that has some evidence of benefit?  How much evidence do we
need to have, before such a program is warranted?  

There are ethical questions lurking in there: Who gets to decide how
much evidence is enough? and, Who gets to decide if the evidence for
the health benefits for breastfeeding meets the standard?
 Keep in mind that if we debate those questions until everyone
is satisfied, we’ll never get anything done.  If your goal in
life is to do nothing, then fine, debate all you want.  I
would argue, though, that at some point, it is time to actually do
something.  

Here we have situation in which the American Academy of Pediatrics and
the World Health Organization both support the position in the
campaign.  The most comprehensive, systematic literature
review that I could find, is consistent with the message in the
campaign.  Isn’t that enough?

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If you’ve had the patience to read this far, you might be interesting
in this exercise in Darwinian medicine: href="http://www.jpeds.com/article/PIIS0022347699703628/fulltext?browse_volume=134&issue_key=TOC%40%40JOURNALS%40YJPED%400134%400001&issue_preview=no&select1=no&select1=no&vol=">Association
of atopic diseases with breast-feeding: Food allergens, fatty acids,
and evolution. J Pediatr. 1999
Jan;134(1):5-7.

Comments

  1. #1 stumpy
    June 21, 2006

    My mother didn’t breastfeed me (she smoked cigarettes and gave me formula), and I’ve been traumatized and deficient — in numerous ways — my entire life, as a result. Just a personal testimonial.

  2. #2 Susan Och
    June 26, 2006

    I think the comparative population studies suffer from an inadequate definition of the question. A more useful study might involve exclusively breastfed babies who were exposed to the same array of germs and viruses as their moms, in order to properly test the theory that mothers pass real-time infection resistance to their babies. Using stay-at-home moms and babes could be seen as a way to skew the study, so we would have to seek out that Holy Grail of working mothers, the on-site daycare. We want to look at successful breast feeding, so we would need to provide lactation consultants, on call 24/7. To really cover the possible permutations, conduct the study during a year with a serious flu season. Or a natural disaster.

    What would the control group be? We could pick 100% formula-fed babies, if we wanted a slam-dunk. Or if we were looking for a group of moms to vilify. If we are really trying to find the optimal strategy for raising a child, we would have to compare our 100% breastfed babies to the general population of babies.

    If we were really curious, we would look at general health and rates of illness, but we would also measure cognitive and social development until at least age six. We would measure the mothers’ sense of well being and try to determine whether breastfeeding has affected the family’s economic status for better or worse. We would examine other family issues, like child spacing, or sibling rivalry, or divorce rates, to see if breastfeeding is affecting family health in one way or the other.

    It’s easy to compare one group of mothers to another and call one good and one bad. And if you were afraid that the parents of tomorrow’s school children might have time to become politically active about public school funding or day-care licensing or cuts to public health funding, you could use breast feeding as an issue to divide and distract.

    We should be looking at what is most likely to produce healthy smart kids and stable functioning families, and then support those choices any way we can.

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