What scientific argument can be presented to question that study?
I am concerned because i have osteoporosis.
jean-claude
>>   UniSci - Daily University Science News
>>
>>   A change in blood acidity caused by a high-protein diet accelerates
>>   osteoporosis by depleting bones of their calcium, say researchers at
>>   the University of Rochester. Their study, which appears in today's
>>   issue of the American Journal of Physiology, reveals for the first
>>   time how bones sacrifice themselves to compensate for the
>>   acid-producing foods we eat.
>>
>>   "When we eat, we generate acid," explains David A. Bushinsky, M.D.,
>>   lead author of the study and professor of Medicine and of Pharmacology
>>   and Physiology at Strong Memorial Hospital at the University of
>>   Rochester. "These acids are ultimately excreted by the kidneys, but as
>>   we age, our kidneys don't function so well. If the kidneys can't keep
>>   up with our appetite, the bones step in and absorb the excess acid.
>>   That's good in the short term, but in the process the bones surrender
>>   calcium, phosphorus, sodium and everything they should be keeping to
>>   stay strong."
>>
>>   The process is called metabolic acidosis and it can become a problem
>>   for a middle-aged or older person whose kidneys are not working as
>>   efficiently as those of a younger person's. Not only does the bone
>>   trade off its calcium for the blood's acid, but the acid environment
>>   hinders osteoblasts, the cells that naturally rebuild damaged bone.
>>
>>   "An older woman with kidney trouble should definitely watch how much
>>   protein she eats," says Bushinsky. As much as 30 percent of
>>   post-menopausal white women, the group at greatest risk, have
>>   osteoporosis. Protein generates more acid than other foods, and the
>>   proteins in red meat generate more acid than those in fish or poultry.
>>   Vegetable proteins give rise to the least amount of acid.
>>
>>   Though scientists have suspected that high levels of acid in the blood
>>   contribute to osteoporosis, this is the first time researchers have
>>   been able to confirm that the bones are actually deteriorating. Using
>>   a prototype machine called an "ion microprobe," Bushinsky was able to
>>   zoom in and identify what made up each layer of a mouse bone.
>>
>>   Up until now, researchers had to test the entire bone, and so would
>>   easily miss the loss of calcium that occurred only at the surface. The
>>   ion microprobe strips away layers of bone like a leaf-blower whisking
>>   away the top dry leaves while the wet ones stay on the lawn. Then it's
>>   just a matter of collecting the blown fragments and analyzing them.
>>
>>   Bushinsky found that in just seven days, mice experiencing metabolic
>>   acidosis had measurable depletion of calcium in their femurs. "But the
>>   calcium depletion probably started just days, even hours after the
>>   blood became acidic," he explains.
>>
>>   Some medications and diseases can hinder the kidneys' ability to keep
>>   the blood pH at healthy levels. The two most common diseases that
>>   limit kidney function are hypertension and diabetes.
>>
>>   This study is funded entirely by the National Institutes of Health.
>>   The ion microprobe was developed by Riccardo Levi-Setti, Ph.D., of the
>>   University of Chicago. - By Jonathan Sherwood
>>   [Contact: [3]Jonathan Sherwood]
>>   3. mailto:[log in to unmask]
>>
>>   05-Nov-1999
>>
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>>References
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