Background: An inverse relationship has been established between serum magnesium and serum lipid levels. By means of breath tests, we tested the hypothesis that magnesium inhibits intraluminal lipid digestion and subsequently causes changes in lipid metabolism. We also investigated the influence of the administration of magnesium chloride on protein digestion and gastric emptying.
Methods: Five healthy volunteers performed simultaneous breath tests for gastric emptying and intraluminal lipid digestion, and six others for gastric emptying and protein digestion. Each test was performed in basal conditions and after the intake of 800 mg of magnesium chloride dissolved in water. Breath samples were taken at regular time intervals and analysed for 13CO2 and 14CO2 enrichment in order to calculate gastric emptying and lipid and protein digestion rates.
Results: The oral administration of a single dose of magnesium chloride resulted in a diminished rate of intraluminal lipid and protein digestion. The most pronounced effect of magnesium chloride, however, was a decreased gastric emptying rate of both test meals. After correction for gastric emptying, no differences were noted in intraluminal lipid or protein digestion. Therefore, the lower lipid levels noted after magnesium supplementation are unlikely to be the result of altered lipid assimilation.
Conclusion: Magnesium chloride slows gastric emptying but does not influence lipid digestion.