Thursday, January 08, 2009

Copper and You: How Much Is Too Much?

Today's limit for the amount of copper you can safely consume in a day—10 milligrams for adults—might need to be downsized.A study to learn more about how the body handles excess copper showed, for the first time, that long-term intake of 7.8 milligrams of copper a day can result in a potentially unhealthy accumulation of this mineral. That's based on analyses of blood, urine and other samples from nine healthy male volunteers, age 27 to 48, who went on a high-copper regimen for approximately 4½ months of the 5½-month investigation.

The high-copper stint lowered one standard measure of the volunteers' levels of antioxidants—healthful compounds that protect cells, the scientists found (American Journal of Clinical Nutrition, volume 81, pages 822-828). The regimen also interfered with some immune system defenses, reducing the volunteers' ability to fight off the Beijing strain of the flu, for instance. And, even though copper excretion increased during the high-copper regimen, the ramped-up excretion rate wasn't sufficient to remove excess copper.The findings are of interest to nutrition researchers worldwide, as well as to the experts who recommend daily intake levels for essential nutrients, and the companies that make vitamin-mineral supplements.

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