Submitted to: Journal of Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/7/2000
Publication Date: N/A
Interpretive Summary: Manganese is an essential mineral that can also be toxic at high concentrations. Magnesium is also an essential mineral and deficiency of magnesium may result in heart irregularities. In this study we have shown that when moderately high manganese is combined with magnesium deficiency in young pigs, sudden death consistent with heart disease is observed. We have also shown that this same dietary interaction results in depressed magnesium concentrations in heart tissue, a condition that potentially increases the probability of fatal heart disease. Thus, a combination of high manganese and low magnesium may precipitate a health problem more severe than moderate manganese toxicity or magnesium deficiency alone.
Technical Abstract: Young pigs were fed a diet moderately high or low in Mn (52 +/- 7 or 2.1 +/- 0.2 mg Mn/kg) and deficient in Mg (100 mg Mg/kg) for 5 weeks. All 8 pigs consuming the high Mn diet died following convulsive seizures, whereas only 2 of 6 died in the group fed low Mn. A subsequent study examined the interaction between deficient dietary Mg and Mn on the tissue distribution of Mg and Mn, in an attempt to determine the cause of death. Pigs were individually fed for five weeks, 100 mg/kg Mg and 2 mg/kg Mn, 100 mg/kg Mg and 50 mg/kg Mn, 100 mg/kg Mg and 50 mg/kg Mn with added UT minerals, or 1000 mg/kg Mg and 50 mg/kg Mn, and ultra-trace minerals. Liver and skeletal muscle Mn concentrations were significantly elevated by increased dietary Mn. Increased dietary Mn did not affect heart Mn, but heart Mg concentrations were significantly depressed by high, as compared to low, dietary Mn (941 +/-81 versus 795+/- 65 ug Mg/g). These data suggest high dietary Mn may exacerbate Mg deficiency in heart muscle, and thus may be a complicating factor in the deaths observed in Mg deficient animals.