Magnesium supplementation improves insulin resistance
Insulin resistance is benefited by magnesium supplementation according to mounting evidence. A study published in the journal Diabetes, Obesity and Metabolism documents significant improvements in insulin resistance by supplementation even when the subjects' magnesium levels appeared normal (normomagnesemic). The authors state:
"The incidence of insulin resistance and metabolic syndrome correlates with the availability of magnesium (Mg). We studied the effect of oral Mg supplementation on insulin sensitivity and other characteristics of the metabolic syndrome in normomagnesemic, overweight, insulin resistant, non-diabetic subjects."
After collecting data on insulin sensitivity, plasma glucose, serum insulin, blood pressure and lipid profiles subjects were randomized to receive either a magnesium supplement or placebo for 6 months.The results offered strong evidence for the ability of magnesium supplementation to improve insulin resistance:
"Mg supplementation resulted in a significant improvement of fasting plasma glucose and some insulin sensitivity indices (ISIs) compared to placebo. Blood pressure and lipid profile did not show significant changes. The results provide significant evidence that oral Mg supplementation improves insulin sensitivity even in normomagnesemic, overweight, non-diabetic subjects emphasizing the need for an early optimization of Mg status to prevent insulin resistance and subsequently type 2 diabetes."
Magnesium, insulin resistance and cardiovascular risk reduction
In another study published in Medical Science Monitor that included subjects with hypertension, magnesium supplementation improved both insulin resistance and blood fats:
"Epidemiological studies have associated low dietary Mg2+ intake with insulin resistance (IR) and increased risk for metabolic syndrome...This study aimed to investigate the effects of oral Mg2+ supplementation on insulin sensitivity (IS) and serum lipids."
Forty-eight patients were divided into a magnesium supplementation with lifestyle recommendations and a lifestyle only group, with measurements of fasting glucose and insulin levels, serum lipids and other standard laboratory tests, as well as an oral glucose tolerance test (OGTT) for insulin sensitivity were made at the beginning and after 12 weeks. Data for the magnesium supplementation group showed numerous improvements not present in the controls:
"In the Mg2+ supplementation group the OGTT-derived IS indices of Stumvoll, Matsuda and Cedercholm in were increased between baseline baseline and study-end. In contrast, none of these parameters were changed in the control group. Reductions in total cholesterol, LDL-cholesterol and triglyceride levels, along with a parallel increase in HDL-cholesterol levels, were evident at study-end in the intervention group, but not in the control group."
Clinical note: Magnesium supplementation should be a routine consideration to lower cardiovascular risk in patients with hypertension, especially with insulin resistance. The authors conclude:
"This study suggests that oral Mg2+ supplementation improves IS and lipid profile in mildly hypertensive patients. These potential beneficial effects of Mg2+ on associated metabolic factors could be helpful for patients with hypertension in terms of overall cardiovascular risk reduction.
Magnesium improves metabolism with normal weight but insulin resistance
And a study recently published in Archives of Medical Research showed similar improvements in insulin resistance and metabolism with magnesium supplementation in a randomized placebo-controlled trial with metabolically obese, normal-weight (MONW) individuals.
"A total of 47 MONW individuals with hypomagnesemia were enrolled in clinical a randomized double-blind placebo-controlled trial. Individuals in the intervention group received 30 mL of MgCl2 5% solution (equivalent to 382 mg of magnesium) and individuals in the control group 30 mL of placebo solution, once daily during 4 months. In the absence of obesity or overweight, the presence of fasting glucose levels ≥100 mg/dL, HOMA-IR index ≥3, triglyceride levels ≥150 mg/dL and/or systolic and diastolic blood pressure ≥140 and 90 mmHg defined the presence of the MONW phenotype. Hypomagnesemia was defined by serum magnesium concentration ≤1.8 mg/dL."
Clinical note: Even with a cut-off point of 2.0 mg/dL serum magnesium is a 'blunt' indicator that misses many if not most cases needing supplementation. Practitioners should be alert to clinical manifestations of suboptimal magnesium levels. Objective verification when necessary can be reliably obtained with the Exa Test.Consonant with other studies magnesium supplementation showed a distinct benefit:
"At basal conditions there were no significant differences between groups. At the end of follow-up, changes in the mean of systolic (–2.1 vs. 3.9% mmHg, p <0.05) and diastolic (–3.8 vs. 7.5% mmHg, p <0.05) blood pressures, HOMA-IR index (–46.5 vs. –5.4%, p <0.0001), fasting glucose (–12.3 vs. –1.8% mg/dL, p <0.05) and triglyceride levels (–47.4% vs. 10.1% mg/dL, p <0.0001) were significantly lower in the subjects who received MgCl2 compared with individuals in the control group."
The authors' conclusion supports the practice of starting early (while weight is normal) with magnesium supplementation to address adverse metabolic changes:
"Oral magnesium supplementation improves the metabolic profile and blood pressure of MONW individuals."
Clinical note: Magnesium may be the element most commonly insufficient universally. Critical to hundreds of metabolic pathways, it is 'nature's calming, antiinflammatory mineral' and supports parasympathetic nervous system function. Deficiency should be highly suspect in the presence of muscle cramps.