Posted: May 09, 2010 5:17 am
CandiceTu wrote:I would like to see if anyone else has any information that I may have missed in this discussion or if there is something that I may have misunderstood, myself.
There are some things that your friend has misunderstood, and some things that you may have misunderstood as well.
First, though, some background: the paleo diet is based on the conjecture that the healthiest diet for modern humans is the one that we are evolved to eat, and that the relevant period of evolution is during the paleolithic - roughly the 2,000,000 years prior to the advent of agriculture and herding in the neolithic. The reason the paleolithic is chosen is because the neolithic - roughly the past 10,000 years - is only sufficient time to expect a few point mutations, and is not sufficient to fully adapt to entirely new foods. The idea is to follow the older, paleolithic, diet as closely as one can within modern constraints.
To anyone who truly believes in evolution, this hypothesis should be compelling. The problem is that we don't actually know for sure how humans ate during the paleolithic. There is some data - enough to establish things like the eating of meat - but not a lot, not enough to fill out all the details one needs to, say, put together a weekly menu.
Hunter gatherers are one proxy people use to try to figure out what we ate during the paleolithic. Unfortunately, modern hunter gatherers may be a poor proxy, as they have generally been pushed onto marginal lands by agriculturalists - unlike paleolithic hunter gatherers, who would have had free rein over all the best lands. However, there may be something to be learned from them, and perhaps more to be learned from accounts of first contacts with hunter gatherer groups which had not previously been exposed to agriculturalists.
I note that with respect to hunter gatherers, both you and your friend seem to harbor some misconceptions. Contrary to what your friend says, few hunter gatherers live into their 80s. However, the frequently cited life expectancy figure of about 30 is life expectancy at birth, and is low primarily because of infant and childhood mortality. Hunter gatherers who survive to 20 typically have a life expectancy of about 40 more years - 34 for the San, 41.4 for the Hadza, and 39.8 for the Ache, for example - so they can expect to survive to an average of 60 years old or so. As pointed out elsewhere in this thread, the main difference between that and modern life expectancies is not diet, but medical technology.
The emphasis on dental features is due to two facts. First, some of the early researchers in this area were dentists. Second, dental caries are easy to examine from collected skulls.
Moving on to what "science" says: most of the accepted wisdom with respect to diet is not actually based on solid science. The actual science suggests that modern agricultural carbohydrates are associated with a plethora of problems including diabetes, heart disease in women, and possibly cancer. Unfortunately dietary recommendations have often been based on medical studies that select correlations to observe but fail to track down actual causations as real science would do. Read Gary Taubes' Good Calories, Bad Calories for an excellent analysis of it - or watch a video of one of his presentations at various hospitals, such as this one:
http://www.dhslides.org/mgr/mgr060509f/f.htm
or
http://video.google.com/videoplay?docid ... 7661765149
CandiceTu wrote:What I find to be particularly hilarious is when I wonder where these individuals who follow the "Paleo Diet" obtain their food. They don't live out in the wild and hunt their own boar or unearth their own tubers and pick their own legumes (most of them, anyway...I'm sure that there's at least a couple out there) from the dense forests in their environment. They either a) buy their food from the grocery stores, or b) grow their own food. In either case, THEY UTILIZE AGRICULTURAL METHODS TO OBTAIN THEIR FOOD. hmmmm *scratches chin* Hypocritical/ironic, no?
Actually, one of the ones I know hunts a lot of his own food. A bear and a moose each year can go a long way. However, as noted above, the diet is about approximating the paleolithic diet within modern constraints, not duplicating it exactly.
Is your friend on the paleo diet? If so, is it working for her? If it is, does it matter whether her reasons for using it are valid or not?