> http://www.medscape.com/viewarticle/431555?srcmp=endo-041202

> Animal Protein Consumption Associated With Bone Density in Elderly Women

> NEW YORK (Reuters Health) Apr 10 - Dietary animal protein appears to play a
> protective role in the skeletal health of older women, according to a
> report in the April 1st issue of the American Journal of Epidemiology.

>> http://www.medscape.com/viewarticle/431555?srcmp=endo-041202

>> Animal Protein Consumption Associated With Bone Density in Elderly Women

>> NEW YORK (Reuters Health) Apr 10 - Dietary animal protein appears to play a
>> protective role in the skeletal health of older women, according to a
>> report in the April 1st issue of the American Journal of Epidemiology.

>Overall, the literature on the relation between dietary protein and bone health
>is mixed.  Different studies of similar quality support protective, detrimental,
>and null relations.  The reasons for the discrepancies are not well understood,
>but a study in the current issue of the American Journal of Clinical Nutrition,
>suggests that the effect on bone of protein in the diet may differ depending on
>the level of calcium in the diet (1).  Specifically, at high calcium intakes,
>protein may be protective; whereas at low calcium intakes, it may be
>detrimental.  

>In an accompanying editorial (2), Robert Heaney proposes a mechanism that could
>account for how protein could affect bone differently depending on calcium
>intake, as observed in the study.  Since bone is 50% protein, higher protein
>intakes should promote bone accretion.  However, higher protein intakes also
>cause increased calcium losses in the urine.  The body responds to this calcium
>drain by drawing from its calcium stores in bone, potentially causing bone
>demineralization, and by increasing calcium absorption from the gut.  The
>fraction of calcium that the body absorbs is partly dependent on the amount of
>calcium in the diet.  At high calcium intakes the fraction is low; whereas at
>low intakes, the faction is higher.  If calcium intake is high (such that
>fractional absorption is low), then the body will up-regulate absorption
>sufficiently, net bone demineralization will not occur, and higher protein
>intakes will promote bone accretion.  In contrast, if calcium intake is low,
>then absorption is already fully up-regulated, and the body cannot further
>increase absorption to offset the calcium drain.  Thus, when intake of calcium
>is low, higher protein intakes cause net bone demineralization.

>-Jay

> >> http://www.medscape.com/viewarticle/431555?srcmp=endo-041202

> >> Animal Protein Consumption Associated With Bone Density in Elderly Women

> >> NEW YORK (Reuters Health) Apr 10 - Dietary animal protein appears to play a
> >> protective role in the skeletal health of older women, according to a
> >> report in the April 1st issue of the American Journal of Epidemiology.

> >Overall, the literature on the relation between dietary protein and bone health
> >is mixed.  Different studies of similar quality support protective, detrimental,
> >and null relations.  The reasons for the discrepancies are not well understood,
> >but a study in the current issue of the American Journal of Clinical Nutrition,
> >suggests that the effect on bone of protein in the diet may differ depending on
> >the level of calcium in the diet (1).  Specifically, at high calcium intakes,
> >protein may be protective; whereas at low calcium intakes, it may be
> >detrimental.

> >In an accompanying editorial (2), Robert Heaney proposes a mechanism that could
> >account for how protein could affect bone differently depending on calcium
> >intake, as observed in the study.  Since bone is 50% protein, higher protein
> >intakes should promote bone accretion.  However, higher protein intakes also
> >cause increased calcium losses in the urine.  The body responds to this calcium
> >drain by drawing from its calcium stores in bone, potentially causing bone
> >demineralization, and by increasing calcium absorption from the gut.  The
> >fraction of calcium that the body absorbs is partly dependent on the amount of
> >calcium in the diet.  At high calcium intakes the fraction is low; whereas at
> >low intakes, the faction is higher.  If calcium intake is high (such that
> >fractional absorption is low), then the body will up-regulate absorption
> >sufficiently, net bone demineralization will not occur, and higher protein
> >intakes will promote bone accretion.  In contrast, if calcium intake is low,
> >then absorption is already fully up-regulated, and the body cannot further
> >increase absorption to offset the calcium drain.  Thus, when intake of calcium
> >is low, higher protein intakes cause net bone demineralization.

> >-Jay

> Thanks, Jay - that makes perfect sense.  So I guess low-fat milk is the
> answer, just like mom always said?

>I worry about the paleos, who eschew dairy but have high-meat diets.

> Thanks, Jay - that makes perfect sense.  So I guess low-fat milk is the
> answer, just like mom always said?

> Paul

> >> Thanks, Jay - that makes perfect sense.  So I guess low-fat milk is the
> >> answer, just like mom always said?

> >I worry about the paleos, who eschew dairy but have high-meat diets.

> That's OK, Steve Harris has it covered - he worries about the meat-eaters
> who drink milk too :-)

> Paul

> > Thanks, Jay - that makes perfect sense.  So I guess low-fat milk is the
> > answer, just like mom always said?

> > Paul

> Animal Protein Consumption Associated With Bone Density in Elderly Women

> NEW YORK (Reuters Health) Apr 10 - Dietary animal protein appears to play a
> protective role in the skeletal health of older women, according to a
> report in the April 1st issue of the American Journal of Epidemiology.
> In a prospective study, Dr. Elizabeth Barrett-Connor, of the University of
> California, San Diego, in La Jolla, California, and colleagues examined the
> associations of total, animal, and vegetable protein with bone mineral
> density (BMD) and bone loss in 572 women and 388 men between the ages of 55
> and 92 years.

> "Multiple linear regression analyses adjusted for standard osteoporosis
> covariates showed a positive association between animal protein
> consumption, assessed by cooking.net">food frequency questionnaires in 1988-1992, and
> BMD, measured 4 years later," the investigators report.

> The association was significant in women. For them, BMD increased by 0.016
> g/cm at the hip (p = 0.005) for every 15-g/day increase in animal protein
> intake. BMD was also increased at the fem{*filter*}neck, spine, and total body
> by 0.012 g/cm (p = 0.02), 0.015 g/cm (p = 0.08), and 0.010 g/cm (p = 0.04),
> respectively.

> Vegetable protein was negatively associated with BMD in both men and women.

> "These findings, along with the intriguing observation of a negative
> association between vegetable protein consumption and BMD, have significant
> implications for osteoporosis prevention strategies and warrant further
> investigation in elderly cohorts," Dr. Barrett-Connor and colleagues
> conclude.

> Am J Epidemiol 2002;155:636-644.

>|The association was significant in women. For them, BMD increased by 0.016
>|g/cm at the hip (p = 0.005) for every 15-g/day increase in animal protein
>|intake.

>I have a different solution.

>Eat vegetables and squat with weight.