On Mon, 20 Dec 1999, Ben Balzer wrote:

> People often say to me "but cavemen only live unti 25 years so how can the
> paleo diet be any good?" with a silly smirk on their faces. A fine example
> of fallacious reasoning or ignorante elenti (Todd no doubt can tell us
> exactly what type of illogic it is). I sent this post to another list.
> Bottom line- if you want to live long and healthy- Paleo is probably a good
> start.

That would be "post hoc ergo propter hoc", which means "after
this therefore because of this."  These people that because
cavemen (allegedly) didn't live long, it was because of their
diet.

> Similarly, the Mediterranean diet (which was associated with the longest
> lifespan where data was available in the 1960s) was also associated with
> fairly short lifespan thousands of years ago- this doesn't discourage its
> proponents..

Good point.

> If one supposes that our diet has gotten "worse" in the last 100 years ( a
> common assumption that may not be true), then life expectancy should be
> reduced by this. Obviously this could be outweighed by the above.
> The short life expectancy of paleolithic people was in no part related to
> chronic or degenerative diseases. It was in no part related to diet-related
> diseases (apart from parasites, starvation, etc). Physical injury and the
> arduous nomadic life and harsh living conditions were the main problems.

Well, the truth is that we don't know what part diet-related
illnesses might have played.  We don't *think* that their diet
shortened their life, and that's probably a reasonable assumption
but it's not something that we can know for sure.

> This life expectancy debate confuses *association* with *cause and effect*.

That's the post hoc fallacy, all right.

> They
> had a low life expectancy and a paleolithic diet, but the *diet was not
> causative of the low life expectancy*.

... as far as we know.

> If one used life tables and excluded
> overweight/obesity/diabetes/hypercholesterolaemia/coronary artery
> disease/stroke/cancer affected individuals, one would have some estimation
> of the modern first world life expectancy on a paleolithic diet- as this
> would already factor in the presence of public hygiene, antisepsis, surgery
> and medicine. There is a biological maximum lifespan for any creature that
> cannot be exceeded- the aim is to find the diet that takes us closest to
> this (and avoids a life on medication etc).

But many of these maladies may well have important non-dietary
triggers.  I recall reading last year, for example, that job
dissatisfaction is statistically a more important risk factor for
heart disease than any of the usual physiological markers.  Paleo
diet won't fix that one.

> The life expectancy argument does not hold water in my humble opinion.

I basically agree.  It remains to be seen whether the paleolithic
diet surpasses the Mediterranean diet in this respect.
Obviously, we are betting that it does but our bets haven't been
called yet.

Todd Moody
[log in to unmask]