
Is There a Copper-Aging Connection?By Judy McBride August 20, 1999Preliminary evidence from animal studies suggests that too little dietary
copper may contribute to aging. That's what Agricultural Research Service researchers
suspect from their studies bolstered by indirect evidence. ARS is the
USDA's chief scientific agency. ARS physiologist
Jack Saari and
colleague Gwen Dahlen at the Grand
Forks Human Nutrition Research Center in North Dakota are looking into
whether copper deficiency spurs sugar molecules to attach to protein molecules.
The process, known as protein glycation, is thought to cause much of the tissue
damage in people with diabetes. And this glycation increases in all of us as we
age. When blood sugar is high, as often occurs in copper-deficient rats, it's
more likely that sugar molecules will attach to proteins--called early
glycation. If sugar levels stay high, the sugars' free ends can attach to other
proteins or other sites on the same protein; that's called advanced glycation.
These cross links bend proteins out of shape, rendering them useless. Saari and Dahlen found that both the early and advanced stages of protein
glycation increased significantly in the rats fed a copper-deficient diet. One
sensitive indicator of advanced glycation was at least sixfold higher in the
copper-deficient rats. It was nearly undetectable in the control rats. Human diets contain more copper than the copper-deficient diets given the
rats. But the average copper content of U.S. diets falls below the suggested
range of 1.5 to 3.0 milligrams daily. Saari speculates that years of eating a diet low in the mineral may
contribute to the age-related decline in tissue function by increasing
glycation. So far, he has looked only at glycation of blood hemoglobin and
serum proteins. But it can also happen to structural proteins that form the
tissues. Learn more about this theory in the August issue of Agricultural
Research magazine at: http://www.ars.usda.gov/is/AR/archive/aug99/copp0899.htm Scientific contact: Jack T. Saari, ARS
Grand Forks Human Nutrition Research
Center, Grand Forks, N.D., phone (701) 795-8353, fax (701) 795-8395,
[email protected]. Story contacts Jack T Saari U.S. Department of Agriculture | |