Effects of high magnesium intake on bone mineral status and lipid metabolism in rats

Effects of magnesium (Mg)-intake on mineral levels in bone, blood and various tissues, bone density and plasma lipids were examined in 4-wk-old, female Wistar rats fed diets of five different Mg-contents of 1/10, 1 (standard diet (Mg 47 mg/100 g diet): control group), 2, 5 and 10-fold of the standard content for 4 wk. In rats fed the 1/10-fold Mg diet, the body weight gain declined with a statistical significance compared to control rats, while no significant differences were observed in rats fed on the 2-, 5-, and 10-fold Mg diets. The imbalance of mineral concentrations in the rats fed 1/10 Mg diet was induced, but in the rats fed high Mg diets were not induced except in tibia. Mg concentration in tibia of rats fed the 10-fold Mg diet significantly increased compared to the control group. All groups (1/10-fold, 2-, 5-, and 10-fold Mg groups) showed no significant changes in tibial mineral levels, except Mg in the 10-fold group, compared to the control group. With increase in Mg-intake, decline of plasma lipid parameters such as cholesterol, triglycerides and phospholipids are induced. Based on these results, it was suggested that a higher Mg-intake (around 5-fold of the standard Mg-content) might have a prophylactic potential against the onset of hyperlipidemia and cardiovascular disease by reducing lipid indices, and Mg decline in bone.