Submitted to: Federation of American Societies for Experimental Biology Conference
Publication Type: Abstract Only
Publication Acceptance Date: April 6, 1997
Publication Date: N/A
Technical Abstract: Twenty-two postmenopausal women aged 47 to 78 y completed a metabolic unit study to investigate the interaction between dietary copper and magnesium that has been found in animal studies (FASEB J 8:A711, 1994, FASEB J 9:A735, 1995). Half of the women were fed a diet containing 1.0 mg Cu/2000 kcal for 160 d, the rest were fed a diet containing 3.0 mg Cu/2000 0 kcal. Both groups received either 100 or 384 mg Mg/2000 kcal for 80 d in randomized double blind crossover design. Serum Mg concentrations were directly related to diet Mg (P<0.004); the changes in serum Mg were greater in the subjects who were fed the marginal Cu diet than those supplemented with Cu. Serum ultrafilterable Mg followed a similar trend (P>0.03). A significant interaction (P< 0.03) between Cu and Mg affected erythrocyte superoxide dismutase activity (ESOD). ESOD was higher in the Cu supplemented subjects (3606 U/g Hgb) than in the marginal Cu subjects (3177 U/g Hgb) when 100 mg Mg/d was fed, but the ESOD was not apparently affected by Cu when 300 mg Mg/d was fed. The sequence in which the Mg supplements were given obscured, or tended to obscure the Mg effects on many of the measured variables such as serum Mg, % ionized Mg, % ultrafilterable Mg, bound Mg, complexed Mg, cholesterol, glucose, and ESOD; changes were greatest when the placebo was fed first and were smaller or lacking when the Mg supplement was fed first. These findings suggest that prior Mg intake or status markedly affects the response to Mg deprivation; prior high Mg inhibits or delays the appearance of Mg deprivation signs.