Bone in Elders
By Judy McBride
April 6, 2001
Its no secret that people need
ample calcium and vitamin D to maintain strong bones, even in their twilight
years. Now, a study suggests that protein intake may be important in reducing
bone loss in elders.
The 70- to 90-year-old men and women with the highest protein intakes lost
significantly less bone over a four-year period than those who consumed half or
less the protein. Animal protein, as well as overall protein intake, was
associated with preserving bone.
The study was conducted by researchers with the
Hebrew Rehabilitation Center
for Aged, Research and Training Institute; Boston University; and the
Jean Mayer USDA Human Nutrition Research
Center on Aging, all in Boston, Mass. Lead author Marian T. Hannan at the
Hebrew center collaborated with Katherine L. Tucker at the
USDA center and others. The USDA center is
funded by the departments chief scientific research agency, the
Agricultural Research Service.
The findings run counter to studies of younger people that found diets high
in protein, especially animal protein, cause the body to excrete more calcium.
However, they confirm several other large population studies showing protein to
have a positive overall effect on bone, according to Hannan.
With data from 615 participants in the Framingham (Mass.) Osteoporosis
Study, the researchers examined the relationship between their protein intakes
in 1988-89 and changes in bone mineral density four years later. They accounted
for all factors known to increase risk of bone loss.
Participants who reported the lowest daily protein intakes--roughly
equivalent to half a chicken breast--had lost significantly more bone in the
hip and spine four years later than those with the highest intakes--equivalent
to about nine ounces of steak and a cup of tuna salad.
The group with the next lowest intake--equivalent to about two cups of
cottage cheese--also lost significantly more bone than the highest-intake
group, but only at the hip. People can search the USDA food composition tables
for the protein content of more than 6,000 foods at:
Scientific contact: Katherine L. Tucker, Jean Mayer USDA Human
Nutrition Research Center on Aging, Boston, Mass., phone (617) 556-3351, fax
(617) 556-3344, firstname.lastname@example.org.