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From: "ARS Servicio Noticiero" <isjd@ars-grin.gov>
To: "ARS News List" <ars-news@ars-grin.gov>
Subject: Is There a Copper-Aging Connection?
Date: Fri, Aug 20, 1999, 4:06 AM
STORY LEAD:
Is There a Copper-Aging Connection?
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ARS News Service
Agricultural Research Service, USDA
Judy McBride, (301) 504-1628, jmcbride@asrr.arsusda.gov
August 20, 1999
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Preliminary 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 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
ARS is the USDA's chief scientific agency.
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Scientific contact: Jack T. Saari, ARS Grand Forks Human Nutrition Research
Center, Grand Forks, N.D., phone (701) 795-8353, fax (701) 795-8395,
jsaari@gfhnrc.ars.usda.gov
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