Ability of a Cocoa Product To Prevent Chronic Mg Deficiency in Rats

The ability of a cocoa-derived product, used in some European countries as a dietary supplement added to milk, to prevent chronic Mg deficiency was investigated. Wistar rats were fed an Mgdeficient diet supplemented with 3% (w:w) cocoa product (271 mg of Mg2+/kg of food). The concentration of Mg2+, Ca2+, and PO4 in plasma, whole blood, skeletal muscle, heart, kidney, and femur was measured after the rats had been fed the diet for 35, 42, 49, and 56 days. These values were compared with the results from rats fed a diet that was deficient in Mg (225 mg/kg of food) and in rats fed a control diet (557 mg of Mg2+/kg of food). On day 56, dietary supplementation with the cocoa product had significantly reduced hypomagnesemia and hypercalcemia and had prevented the appearance of hypophosphatemia caused by Mg deficiency. The cocoa-supplemented diet also substantially reduced the decreases in Mg in muscle, heart, and bone caused by Mg deficiency. Ca deposits in skeletal muscle and kidney were reduced, as were P deposits in kidney. Mobilization of P from bone was also prevented. These findings show that the regular use of the cocoa product as a dietary supplement effectively prevented the negative nutritional effects of the long-term intake of a diet moderately deficient in Mg.