Research appearing in the American Journal of Hypertension (published online Aug. 12, 2010) looked at the relationship between serum magnesium levels and carotid artery plaques. The subjects were 728 Japanese men and women with a mean age of 67. Low serum magnesium was found to be strongly associated with IMT (intima-media thickness) and carotid plaques.

This makes sense because magnesium influences vascular tone and is a cofactor for acetylcholine-induced endothelium dependent relaxation. Other research that appeared in Magnesium Research (Volume 1, Number 1, February 2010) looked at magnesium supplementation and its effect on the health of the blood vessel lining. The subjects of the study were 60 elderly diabetic patients. Thirty of the subjects, mean age 71, received 368 mg of magnesium supplementation (given as 4.5 g of magnesium pidolate). The other 30 received no supplementation and acted as a control group. Endothelial function was evaluated by flow-mediated dilatation of the brachial artery at the start of the study and again after 30 days of intervention. Supplementation with magnesium resulted in a significant improvement of the post-ischemic endothelial-dependent flow-mediated dilation.