>The Paleolithic Diet and Its Modern Implications is an Interview with Loren
>Cordain, PhD done by Robert Crayhon, MS (both, by astonishing coincidence,
>members of our little group). The interview is at:
>
> http://www.lifeservices.com/cordain.htm
from the interview :, some questions came in my mind
>Loren Cordain: Epidemiological studies have suggested that increased animal
protein intake is associated with higher rates of osteoporotic fracture, and
many metabolic trails have demonstrated increased urinary calcium losses
with increased protein intake. However, in order to firmly establish cause
and effect, and hence proof, that a certain variable is responsible for a
certain effect, scientists conduct intervention trails. To my knowledge
intervention studies have not been able to show that a change from
low/moderate to high protein intake increases that rate of kidney stones or
bone loss in either humans or animals. >
what is intervention trials?
i started to eat more animals over a year ago, and a bone density test
showed fragile spine and to a lesser extent, legs too. I am taking cortisone
for 19 years, ( good enough reason to to have osteoporosis) but i am getting
lot of fruits and vegetables, sunshine, and plenty of exercices (obviously
it was not enough to compensate the side effect of cortisone therapy).
I didn't have bone density done before augmenting my animal intake, so i am
not in mesure to interepret those fact one way or an other, but it make me
doubt about eating more animals.
loren Corain interview continue...
<Stone age diets clearly were characterized by extremely high protein
intakes by modern standards, yet bone robusticity and density (determined
from fossil paleolithic humans) were greater than or equal to that of most
modern humans despite the total absence of dairy products in stone age
diets. This seeming paradox (low calcium intake, high protein intake yet
strong dense bones) may probably be explained by multiple factors. Stone age
humans were more active than modern people and consequently the everyday
work they did resulted in greater bone loading, which in turn can influence
bone density. Further, they lived outside most of the day so their sunshine
exposure and hence vitamin D status would likely have been superior to most
modern people who work indoors and get little sunshine exposure.
Lastly, and most importantly, the critical dietary factor influencing bone
metabolism and hence osteoporosis is not calcium intake, nor calcium
excretion, but rather calcium balance. The acid base status of the total
diet rather than calcium intake or excretion determines calcium balance
(Barzel US. The skeleton as an ion exchange: implications for the role of
acid-base imbalance in the genesis of osteoporosis. J Bone Miner Res. 1995;
10: 1431-36). Foods which yield a net acidic load mainly as sulfates and
phosphates cause the kidneys to respond to this dietary acid challenge with
net acid excretion, as well as ammonium and titratable acid excretion.
Concurrently, the skeleton supplies buffer by active resorption of bone.
Consequently, calciuria is directly related to net acid excretion (Barzel
US, Massey LK Excess dietary protein can adversely affect bone. J Nutr 1998;
128:1051-53). Foods which cause a net acid excretion include meat, fish,
cheeses and grains (Remer T, et al. Potential renal acid loads of foods and
its influence on urine pH. J Am Diet Assoc. 1995 Jul; 95: 791-97). Fruits
and vegetables have a net alkaline value and consequently reduce acid
excretion and hence reduce calciuria thereby halting bone resorption and
actually allowing bone accretion to occur. Although the dietary calcium to
protein ration in stone age diets would have been quite low, the large
amount of fruits and vegetables (35% of total energy) included in the diet
would have produced a net dietary acid-base status which would have favored
bone accretion even in the face of enormous protein intakes.
Similarly, nephro and urolithiiasis would have been reduced from the high
levels of fruit and vegetable consumption via their ability to reduce the
potential renal acid load.
like i said i ate lot of fruits and vegetables, no grains or dairy , 2 to 4
meals a week with animals, for 10 years (before i was heavy, grain and
dairy eater), for one year now i am eating less fruits ,little more
vegetables of and 1 meal a day animals products. Before this last year my
body was certainly on the alcaline side and must still be well balanced ,
acid alcaline wise , but i am loosing my bones any way ( and teeths from my
opinion, despite the fact i am told by specialists that osteoporosis don't
affect teeths).
does cortisone will affect my acid alcaline balance, rendering all those
fruits and vegetables, sunshine and exercises worthless ?
i need some more clues about this relationship between animal proteins and
calcium (how the paradox of hunter gatherers bone density can be explained
more?)
About trials , it is for years that i will be willing to be part of a study
on autoimmune processes and diet, i would like to be followed in my
experiments with diets to deal with my condition (smith syndrome ,(addison +
hypothyroidy)). I would like to be connected with searchers instead of MD
I AM TIRED of MD inertia and conservative approach who go by their
textbook,instead of seeing that , because of my " healthy" life style i
don't fit in their frame of references ) all studies being done with cooked
food or and grain dairy eaters.
Jean-claude
|
