Joel,
Coming from the Dairy State, I'll probably be executed for saying
this, but some abstracts say Milk isn't so good in the long run. I
have heard that it's not all good for the kidneys...
Check out the studies at the end of this message; one shows how milk
protein is BAD for aging rats, and another shows how it benefits young
(growing) rats, but doesn't seem to matter with older rats.
...Rodney (not a nursing calf)
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Dietary soybean protein compared with casein retards senescence in the
senescence accelerated mouse.
Authors: Umezawa M, Hosokawa M, Kohno A, Ishikawa S, Kitagawa K, Takeda T
J Nutr 123 (11): 1905-1912 (Nov 1993)
The effects of replacing dietary casein with soybean protein on mean life
span, mean life span of the last one-tenth of a group, grading scores of
senescence and deposition of senile amyloid were investigated in
senescence accelerated mice (SAM-P/1) compared with a control strain
(SAM-R/1). SAM-R/1 mice fed the soybean protein-containing diet had mean
life spans of 618 +/- 42 d (males) and 578 +/- 62 d (females), 58% (males)
and 44% (females) longer than those of corresponding casein fed mice (P <
0.01). Similarly, in SAM-P/1 mean life-spans were 265 +/- 16 d (males) and
307 +/- 23 d (females) in the soybean diet group, 27% (males) and 30%
(females) longer than in the casein diet groups (P < 0.01). The mean life
span of the last one-tenth of each group fed soybean protein was
significantly longer than the corresponding group fed casein. In SAM-R/1
mice, pathological studies revealed that severe secondary amyloid
deposition (amyloid A protein) in the kidneys, spleen, stomach and liver
was significantly suppressed, in males only, by replacing casein with
soybean protein (P < 0.01). The occurrence of contracted kidneys caused by
the infiltration of amyloid A protein was suppressed in SAM-R/1 mice fed
the soybean protein-containing diet (P < 0.05). The deposition of senile
amyloid in SAM-P/1 mice with aging was retarded by replacing casein with
soybean protein (P < 0.01). These results indicate that dietary protein
source is important in modulating the advance of senescence in SAM mice.
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The effect of a vegetarian diet on protein and fat metabolism values in
rats of various ages
Authors: Krajcovicova-Kudlackova M, Ozdin L
Vet Med (Praha) 38 (7): 413-425 (1993)
Male len rats at the age of 30-140 days were administered a diet with an
optimum content of nutrients in dependence on their age in which the
source of proteins was this: milk casein (essential acid to nonessential
acid ratio E/N = 0.79), soya (defatted and without inhibitors of digestive
enzymes, E/N = 0.73), wheat gluten (E/N = 0.30), and their mixture (with
one-third portions of each protein, E/N = 0.54). The dietary protein
values were adjusted to optimum values according to the quality with
respect to casein (without amino acid fortification). Protein utilization
(net protein ratio NPR) was determined in weekly intervals,
triacylglycerol and cholesterol concentrations in the blood serum were
determined on the 70th and 140th day of age. A proteosynthesis rate was
determined isotopically as L-/U-14C/-tyrosine incorporation in the protein
fractions of liver and muscle in 12 hours after intraperitoneal
application of the isotope in the rats in the period of rapid growth and
in the adult rats on a casein--gluten diet. The isotopically determined
values of tyrosine in the liver and muscles are significantly lower for
the age of 70 days and gluten diet in comparison with the casein values.
The proteosynthesis rate at the age of 140 days is identical. A direct
relation was also found between protein utilization and the values of the
amino acid score of limiting amino acids AS and the potential biological
value of the diet BHp in growing rats at the age of 30-98 days (AS-K/Met +
Cys/2/67, S/Met + Cys/2/63, G/Lys/28, mixture/Met + Cys/2/67; BHp-K 70.0;
S 65.1; G 54.1; mixture 77.0; NPR/70 days/-K 2.00; S 1.48; G 1.22; mixture
2.07). In adult rats (from the age of 105 days) the utilization of the
diet from vegetable sources is equalized with the utilization of the diet
from animal sources, hence it does not depend on the aminogram quality.
The results demonstrate the insufficiency of vegetable sources of food
with respect to proteosynthesis and the content of limiting amino acids
(decisive for the synthesis of peptide chains) in the period of the
organism development. In adult rats the values of the aminograms of food
vegetable sources are sufficiently high with respect to the lower rate of
proteosynthesis (not for the growth but for the organism maintenance,
tissue regeneration).
Joel Sassone (joels at gol.com) wrote:
: Hello,
: I've been wondering what, if any, consensus with regards to the merits and
: demerits of dairy products, especially including yoghurt, skim milk, and
: cheese, for someone attempting to live a long a healthy life. Anyone have
: any comments?
