Magnesium is an essential trace element consumed mainly through the diet. It is present primarily in cells and bones, with serum magnesium accounting for a small fraction, making it difficult to assess serum magnesium levels. However, magnesium plays a crucial role as a physiological regulator of muscle and vascular tone. It is also necessary for the stability of the nervous membranes, preventing their excessive excitability (which is lost, for example, in epilepsies). It acts as a natural antagonist of sodium and calcium, which are known to contribute to hypertension. Previous studies have shown that low serum magnesium levels lead to metabolic imbalance in patients with diabetes, increasing the risk of peripheral arterial disease (PAD), a chronic atherosclerotic disease that primarily affects the lower extremities.
In a recent article published in PLoS One, researchers conducted a cross-sectional study to investigate the association between dietary magnesium intake and PAD. In the present study, the researchers determined PAD by measuring the ankle-brachial index (ABI), where an ABI of less than 0.9 in at least one ankle (left or right) indicated PAD. Additionally, they measured systolic blood pressure in both ankles and in the brachial artery of the right or left arm. The subject-guided 24-hour dietary recall method helped researchers compile a list of foods/drinks a person consumed in 24 hours. Then, they used references to national nutritional standards of United States to determine each subject’s dietary magnesium intake over the past 24 hours.
Furthermore, they divided dietary magnesium intake into four quartiles, with Q1 to Q4 indicating magnesium intake between ≤179mg and >343mg. The researchers performed an ABI test on all NHANES participants aged ≥40 years, for a total of 9,970 individuals. After exclusions for two-sided ABI data and missing covariates, the final analysis sample included 5,969 participants. Of these, 409 and 5,560 individuals made up the PAD group and control group, respectively. The authors noted an association between the intake of trace elements, particularly magnesium, and the development of PAD. Consequently, Q1 was associated with a higher incidence of PAD, with a probability of 1.56. This association remained significant in people without comorbidities and who were never or previously smoked.
Additionally, study analysis revealed a possible interaction between dietary magnesium intake and age. The findings also showed that the magnesium intake of middle-aged and elderly people in the United States is lower than the recommended intake. Subjects without PAD and with PAD, on average, consumed 288.30 mg/day and 244.89 mg/day of magnesium per day, both less than the recommended intake. Several factors increase the risk of PAD in magnesium deficiency. First, magnesium acts as a calcium antagonist; promotes vasodilation and blood circulation by reducing vasoconstriction. It is also a calcium antagonist in the context of blood coagulation: in this sense, magnesium can contribute to the prevention of thromboembolic episodes connected to PAD.
Secondly, it also reduces calcium deposition in the vascular wall and vascular calcification (leading towards atherosclerosis). Finally, magnesium reduces the levels of inflammatory factors, such as C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6). It is not difficult to access foods rich in magnesium at the table and to do prevention. All legumes are rich in them, passing through nuts especially Brazil nuts (350-380 mg%), almonds and cashews (250-290 mg%) and walnuts and peanuts (about 200 mg%). Among the seeds, pumpkin seeds are among the richest in magnesium: they contain about 530 mg per 100 grams. Flaxseeds, sesame and sunflower seeds contain between 350 and 400 mg. At the bottom of the ranking are salad vegetables such as green lettuce, spinach, rocket and green radicchio.
So we see that it is not difficult, even having a snack, to be able to stock up on this precious and little-considered mineral.
- edited by Dr. Gianfrancesco Cormaci, PhD, specialist in Clinical Biochemistry.
Scientific references
PLoS One. 2023 Aug 11; 18(8):e0289973.
Diab Vasc Dis Res. 2023 Jul-Aug; 20(4).
EuroIntervention. 2023; 19(3):232-239.Â
Nutrients. 2023 Feb; 15(5):1211.