Adequate Copper Saves Bones During Weight Loss

Part of the overall efforts of researchers to help reduce obesity rates in the United States is to look carefully at the physiological changes that take place during weight loss.

A human study headed by scientists at ARS’s Grand Forks ( North Dakota) Human Nutrition Research Center has shown specific findings about the importance of adequate amounts of copper during the process of losing weight.

The researchers reported that, based on a carefully controlled human nutrition research study, the copper requirements of women while losing weight exceed the current recommended levels for the participants’ age range.

When people, particularly obese people, go on weight-loss diets, they often lose calcium from their bones. ARS physiologist Henry C. Lukaski presented the findings in abstract form at a meeting sponsored by the American Society for Clinical Nutrition. Lukaski is assistant director of the center.

Some of the women in the study received daily supplements of 3 milligrams (mg) of copper, and the others received supplements of only 1.23 mg. Both levels exceeded the current Dietary Reference Intake (DRI) for copper for women older than 19, which is 0.9 mg.

All participants, who ranged in age from 25 to 35 years old, were then put on a weight-loss diet. During the diet, the researchers tracked the participants’ loss of calcium with isotopes. The study showed that the women who took 3 mg of copper retained more calcium in their bones than women fed 1.23 mg of copper and also maintained their pre-weight-loss bone-mineral density.

“The higher copper intake appears to have helped those participants retain more calcium,” says Lukaski.

The study suggests that during weight loss, the current DRI for copper may not be adequate.

Good sources of copper include green vegetables, mushrooms, seafood, liver, nuts, seeds, wheat bran, cereal, and whole grains. For a list of foods that are good sources of copper, go to www.nal.usda.gov/fnic/foodcomp/Data/SR17/wtrank/wt_rank.html and click on “copper.” The list will sort foods in descending order by copper content in terms of common household measures.—By Rosalie Marion Bliss, Agricultural Research Service Information Staff.

Henry C. Lukaski is with the USDA-ARS Grand Forks Human Nutrition Research Center, 2420 2nd Ave., Grand Forks, ND 58202; phone (701) 795-8429, fax (701) 795-8230.

"Adequate Copper Saves Bones During Weight Loss" was published in the March 2006 issue of Agricultural Research magazine.