[escepticos] ¿El pelo del feto causa revoltura?

[Moreno]

Bueno, las referencias prometidas:
esta hipótesis la expresó la bióloga Magie Profet en "Pregnancy sickness
as adaptation". Podéis buscar información al respecto por internet.
Resumo un par de referencias que he encontrado a su trabajo:
En http://www.morningsickness.eu/ (sí, sí, en serio):
<<As for root causes, this issue is still somewhat controversial. A
notable current scientific hypothesis is that morning sickness exists as
a safeguard for the embryo's health. Biologists Gillian V. Pepper and S.
Craig Roberts have done a study that indicates that the intake of
alcohol, sugar, oils, and meat can trigger morning sickness. This then
acts as a way of discouraging ingestion of less healthy foods.[1]
According to Margie Profet, eating vegetables may be a factor as
well.[2] Vegetables produce a small amount of toxins to deter insect
infestation and while these toxins are normally harmless to adult
humans, they are potentially dangerous to embryos.[3] Additionally,
morning sickness begins at the point when the embryo's organ systems are
being laid down and the embryo is most vulnerable to birth-defect
inducing chemicals, but is growing slowly and has only a modest need for
nutrients. By the 14th-16th week, when morning sickness typically wanes,
the organ systems of the embryo are mostly complete and the most
prominent need is now nutrients. Women afflicted by morning sickness
typically avoid "bitter, pungent, highly-flavored, and novel foods,"
foods which are likely to contain toxins. Foraging people are at an
unusually high risk of ingesting plant toxins, due to wild plants being
a substantially larger part of their diet than civilized people's. Thus,
morning sickness offers an evolutionary advantage, as studies have shown
that women with more severe morning sickness have less chance to
miscarry as well as less chance to have children with birth defects (see
below), which explains its prevalence among most women and why it is a
universal phenomenon across the human race.>>

Aunque en
http://www.viamedica.pl/gazety/gazetaJ/darmowy_pdf.phtml?indeks=12&indeks_art=191
vienen a decir que:
<<     Profet [11] has suggested that the nausea of pregnancy is
caused by a recalibration of the chemoreceptor trigger zone
in the area postrema, a region of the medulla where toxins
can be detected in the circulating blood and vomiting initia-
ted. She goes on to suggest that a decrease in the mother’s
threshold for taste and smell occurs as a protective mecha-
nism for screening out toxins from the embryo during the
first trimester of pregnancy. As a result of this threshold shift,
previously desired foods with strong taste and/or odors, like
coffee, strong smelling cheese, etc., are nauseating and are
thus avoided. Profet calls attention to the adaptive value of
pregnancy sickness; however, other investigators (e.g., Brown,
Kahn, & Hartman [12] have questioned the validity of Pro-
fet’s theory, citing an absence of supporting data.>>

Vamos, que de momento parece que no pasa de paja mental.

Un saludo.


On Fri, 14 Mar 2008 06:51:10 -0700, "Moreno" <magofreston en fastmail.fm>
said:
> 
> On Fri, 14 Mar 2008 10:17:20 +0100, "Inés Toledo" <inesucu en gmail.com>
> said:
> > > El 14/03/08, Moreno <magofreston en fastmail.fm> escribió:
> > >
> > > > La conjetura a la que yo había dado más credibilidad es que ciertas
> > >  >  sustancias tóxicas presentes en los vegetales, aunque son inocuas para
> > >  >  un adulto, pueden ser desastrosas para el feto. Los vómitos permitirían
> > >  >  deshacerse de estas sustancias.
> > >  >  Había también estudios que apoyaban esta hipótesis sobre abortos
> > >  >  naturales o malformaciones en el feto. También se relacionaba la época
> > >  >  de aparición de las náuseas con la fase de desarrollo del feto en la que
> > >  >  sería más vulnerable a estas sustancias. A ver si esta tarde tengo
> > >  >  tiempo y busco las referencias.
> > >  >
> > >
> > >
> > > (IT) Pero aparecerían vómitos únicamente si se toman esas sustancias
> > >  tóxicas... no entiendo muy bien lo que dices.
> 
> Claro, aparecerían al tomar alimentos que probablemente contengan
> toxinas... que son muchos.
> 
> > 
> > Yo sabía lo de los vómitos de los dos (más o menos) primeros meses.
> > Nunca tuve noticia de otro periodo de náuseas a los cinco-seis
> > meses...
> 
> No entiendo, ¿de dónde sale este segundo periodo?
> 
> > 
> > -- 
> > Inés
> > 
> > http://blogdeinestoledo.blogspot.com/
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