[extropy-chat] Failure of low-fat diet

[Rafal Smigrodzki]

On 2/27/06, Robin Hanson <rhanson at gmu.edu> wrote:
> At 06:29 PM 2/27/2006, Rafal Smigrodzki wrote:
> > > > >> But you didn't answer my question. What do you think stopped people
> > > > >> dying of those diseases, if it wasn't the vaccines?
> > > > >
> > > > > There are lots of logical possibilities, and my state of belief is
> > > > > that I am very uncertain about which one it might be.
> > > >
> > > >Which is most consistent with the sum of our scientific knowledge
> > > >about the the causes of various diseases? ...
> > >
> > > Here is one explanation that has a plausible mechanism and isn't clearly
> > > contradicted by the data.   Mammals invoke the stress response in
> > situations
> > > they consider stressful, which helps the devote energy to their muscles
> > > at the expense of other systems such as the immune system.   This reduces
> > > long term health.   As humans become richer they interpret fewer events as
> > > being stressful and invoke the stress response less often, and so are
> > > healthier.
> > > There is a multiplier effect for contagious diseases, so that
> > healthier people
> > > living near each other benefit each other.   So a theory is that
> > our increasing
> > > health is caused by our feeling less stress as we have gotten richer.
> >
> >### Are you saying that exposing rich people to infectious agents they
> >have not been vaccinated against will not result in significant
> >morbidity?
> >This would be a very interesting claim...
>
> I would not make that claim; all this story needs is a reduced
> susceptibility for
> rich people, all else equal.

### Since the greatest gains in survival have been observed in small
children, this story would also have to posit economic factors as
primarily responsible for reduced susceptibility of children to
infectious disease, as opposed to a combination healthcare factors,
with a secondary contribution from lifestyle changes enabled by
affluence. Do rich neonates feel sufficiently rich to have a "reduced
susceptibility" to e.g. polio?

Clearly, the likelihood of surviving an infectious illness depends on
the level of stress you are under, and I mean something else than
purely psychological stress. Under natural conditions most humans have
to cope with substantial burdens of parasite infestations, coupled
with frequent exposure to large inoculations of various microorganisms
from injuries and contaminated food. Psychological stress, although it
is the focus of our modern attention, is a relatively smaller
component of overall stress in the EEA.

I would expect that there is a nonlinear survival response to
reduction of single infectious risk factors: if you vaccinate only
against smallpox, children will still keep dying from a myriad of
other causes. Yet, if you vaccinate against the top 10 diseases,
eradicate fleas, intestinal roundworms, lice, trichinosis, and give
much better nutrition, the gains will have a synergistic effect - at
some tipping point the overall reduction of chronic stress will allow
an effective response to challenges that would have killed you if you
for example still had large (1- 1 1/2 foot long) worms feeding inside
your gut.

This effect is likely to explain the difficulty in measuring the
impact of single healthcare interventions on survival and would
obviate the need to seek explanations by a roundabout way, in economic
factors affecting adults.

I also find it important not give legitimacy to, for example, parents
who deny vaccinations to their children. Theorizing about why you
might not need basic medical care simply because you are feeling rich
may be harmless in itself but sometimes may be taken over by people
with unusual agendas.

Rafal