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.

D's points are quite valid but our current longevity has nothing to do
with our modern diet. One might say that our modern diet is more unhealthy
than it was 100 years ago- certainly it has much higher GI etc. The
Neolithic diet has been going on for 10,000 years. Last century, life
expectancy was about 35-45 years in first world countries if memory serves
me correctly.

Our high life expectancy is more related to public hygiene, antisepsis,
aseptic surgery, immunisation, antibiotics, anithypertensive therapy,
diabetic therapy etc than to any improvements in the diet in the last 100
years. I would hate to think of what our life expectancy would be without
these measures.

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..

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.

This life expectancy debate confuses *association* with *cause and effect*.
They
had a low life expectancy and a paleolithic diet, but the *diet was not
causative of the low life expectancy*.

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).

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

I did a search on the paleodiet archives and came up with these: (I haven't
added any comments)

Caloric restriction is said to prolong animal and human lifespans
http://maelstrom.stjohns.edu/CGI/wa.exe?A2=ind9903&L=paleodiet&P=R2


http://maelstrom.stjohns.edu/CGI/wa.exe?A2=ind9704&L=paleodiet&P=R1082
states in part:
"I suppose life expectancy at birth for Pleistocene hominids may have been
around 30 years but not necessarily that low. The main cause of a low
figure would be high mortality rates among infants, children and
adolescents. Life expectancy at 30 may very well have been an additional 25
years or more. How much more can not be estimated by use of available
osteological methods [Isçan, M. Y., Kennedy, K. A. R. (1989).
Reconstruction of life from the skeleton. New York, Wiley-Liss].

Age estimations are very difficult after middle age and fossil remains are
often classified as belonging to a human aged "40 years or more". An age
process is not equally rapid in different humans, samples are often small
and many of the age processes are influenced by lifestyle (e.g. bone loss).
Other problems are lack of contemporary autopsy material for comparison,
bone changes occuring after death, selection bias, different disease
patterns during different times and insufficient standardization of age
estimation methods."

http://maelstrom.stjohns.edu/CGI/wa.exe?A2=ind9704&L=paleodiet&P=R579 states
in part:
"These longevity figures are for skeletons where the age at death was
determined using standard "paleopathological" techniques, for prehistoric
humans who lived in the Eastern Mediterranean where a lot of research has
been done and the data is available. Main thing to note here about the
short average lifespans compared to modern times is that the major causes
are thought to have been "occupational hazards," i.e., accidents, trauma,
etc., stresses of nomadism, and so forth. [Source: Angel, Lawrence J.
(1984) "Health as a crucial factor in the changes from hunting to developed
farming in the eastern mediterranean." In: Paleopathology at the Origins of
Agriculture. (proceedings of a conference held in 1982) Orlando: Academic
Press. pp.51-73]

                                                         Median Lifespan
(yrs)
                                                            MALE    FEMALE

- 30,000 to 9,000 B.C.                                      35.4     30.0

(late "Paleolithic" times)

- 9,000 to 7,000 B.C.                                       33.5     31.3
("Mesolithic" transition period from Paleolithic
  to some agricultural products)

- 7,000 to 5,000 B.C.                                       33.6     29.8
("Early Neolithic," i.e., agriculture first spreads
widely)

- 5,000 to 3,000 B.C.                                       33.1     29.2
("Late Neolithic," i.e., the transition is mostly complete

- 3,000 to 2,000 B.C. ("Early Bronze" period)               33.6     29.4
- 2,000 to 1,450 B.C. ("Middle People/Bronze Kings")        36.5     31.4
- 1,450 to 1,150 B.C. ("Late Bronze")                       39.6     32.6
- 1,150 to 650 B.C. ("Early Iron")                          39.0     30.9
- 650 to 300 B.C. ("Classic")                               44.1     36.8
- 300 B.C. to 120 A.D. ("Hellenistic")                      41.9     38.0
- 120 to 600 A.D.                                           38.8     34.2
- Medieval Greece                                           37.7     31.1
- Byzantine Constantinople                                  46.2     37.3
- 1400 to 1800 A.D. ("Baroque")                             33.9     28.5
- 1800 to 1920 A.D. ("Romantic")                            40.0     38.4
- "Modern U.S. White" (1982-ish presumably)                 71.0     78.5

I am not entirely sure what to make of these figures, but all other things
being equal (which they may not have been, I don't know) longevity seems to
have decreased slightly during the first several millennia after the
introduction of agricultural foods, then gradually rebounded. If true,
wouldn't this indicate that meat/protein consumption itself could not have
been the factor responsible for decreased longevity? (Looks like it would
to me.) From some of the later time periods involved where civilizations
were known to be on the rise or fall, it appears that social factors have
the biggest impact on longevity, particularly since longevity never rose
above about age 45 for long, often falling below that figure for centuries
at a time, until the 1900s, since which time it has almost doubled."




BTW, when we say "life expectancy" we often mean the average age of death.
WHich will be low if infant mortality is high even if the survivors live
long lives- eg if infant mortality is 66.6% but the survivors live until 90,
we could give a "life expectancy" of 30! Life expectancy more trulky
reflects the life expectancy of an individual at a aparticular age- eg an 80
year old may have a life expectancy of 98- as they have already proven they
are made of fairly good material. Whereas a 5 year old will have a life
expectancy of 80 or so.