By MedHeadlines • Jun
11th, 2008 •
Researchers at the University
of Illinois have recently announced the findings of a study which compared the
merits of a diet based on the currently recommended food pyramid and a diet based on lean meats
and low fat dairy products. Diets high in
meats and dairy have been thought to leach calcium from the bones, diminishing their
strength and threatening osteoarthritis over time.
Working with a
group of 130 study participants reporting to the University of Illinois and
Pennsylvania state University, the research team
randomly assigned one diet or the other to the participants, who were all overweight and of middle age. The study
called for active weight loss for the first four months of the
study, followed by eight months of weight maintenance.
At the beginning
of the study, each participant’s bone mineral density and content were measured
using scans of the entire body, the hip, and the lumbar spine. Comparative scans were conducted
again four months into the study and at the eight- and 12-month marks.
Study participants
following the lean meats and dairy diet maintained an overall stable rate of bone density throughout the study
period. The group eating according to the food pyramid experienced a
decline in the health of their bones over the study
period. Ellen Evans, an associate professor in the kinesiology and
community health departments at the University of
Illinois, attributes the stability in bone health in the lean-meat diet group to the
dietary protein, calcium, and vitamin D fortification in the foods they were
eating. Evans is a member of the University of Illinois Division of Nutritional Sciences and is primary author of
this study.
High-protein diets have been strongly associated
with elevated levels of urinary calcium, thought to signal the leaching of
minerals from the bones, also called demineralization. The
research team cites a different mechanism for the increased calcium in the
urine.
Using a process
called radiolabeling, the researchers determined that the increased level of
urinary calcium comes from the intestinal tract’s ability to absorb calcium
better on the lean meat-based diet and not a result of bone loss at all.
Details of the
study can be found in the Journal of Nutrition’s June issue. The study
was funded by The Beef Board, the Illinois Council on Food and Agricultural
Research, Kraft Foods, the National Cattlemen’s Beef Association, and the US
Department of Agriculture.
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