Study: Magnesium and high blood pressure

reference

Kass L, Weekes J, Carpenter L. Effect of magnesium supplementation on blood pressure: a meta-analysis.Your J Clin Nutr.February 8, 2012. doi: 10.1038/ejcn.2012.4. [Epub ahead of print]

design

Meta-analysis. Of the 141 papers identified, only 22 studies with 23 data sets (N=1,173) and a follow-up period of 3 to 24 weeks met the inclusion criteria with a supplemented elemental magnesium range of 120-973 mg (median dose 410 mg). ).

Key findings

There was a greater reduction in blood pressure in crossover studies. This means that when people with high blood pressure didn't take magnesium, their blood pressure was higher; When they took magnesium, their blood pressure was lower. In addition, the higher the magnesium dose, the lower the blood pressure. Combining all studies, there was a decrease in systolic blood pressure (SBP) of 3-4 mmHg and diastolic blood pressure (DBP) of 2-3 mmHg, which further increased in crossover studies and intake >370 mg/day. The authors concluded that magnesium supplementation appeared to produce a small but clinically significant reduction in blood pressure. They called for more studies.

Effects on practice

The most important message from this meta-analysis is that magnesium actually lowers blood pressure.

We must remember that meta-analysis homogenizes all available information in a large blender and arrives at a number that is not necessarily the final answer to the study's question. In the authors' words: "This meta-analysis was conducted to evaluate the effect of magnesium supplementation on [blood pressure] and to identify the characteristics of the studies that demonstrated the greatest effect size."

The authors found that the higher the amount of magnesium, over 370 mg/day, the greater the reduction in blood pressure. None of the 22 selected studies calculated the food intake of the subjects. The subjects came from 12 different countries, so we can't know whether any of them had a magnesium deficiency to begin with. There are many other variables in such an analysis, but despite all the disadvantages, we should remember the conclusion and build on this result.

For example, a dose of 370 mg of elemental magnesium is hardly clinically equivalent to the recommended daily dose, a value that prevents clinical magnesium deficiency symptoms. Magnesium administered therapeutically is usually in a higher dosage.

You can use this study to tell your patients that magnesium has been shown to lower blood pressure in numerous clinical studies.

In theMagnesium miracleI wrote: "25 years of research show that, under ideal conditions, about 300 mg of magnesium is required just to replenish daily losses. Since, at best, the body only absorbs half the amount consumed, researchers believe that most people would benefit from magnesium supplementation. Otherwise, body tissue must be broken down to supply vital magnesium to vital areas of the body.^1.2

“If you are under mild to moderate stress caused by a physical or mental illness, physical injury, exercise, or emotional upheaval, your magnesium needs increase from 6 mg/kg/day to up to 10 mg/kg/day.^3.4exposure to fluoride in water or dental products,⁵a diet high in protein,6 alcohol,^7.8high doses of vitamin D,⁹and B12¹⁰increase the need for magnesium. An average good diet can provide about 120 mg of magnesium per 1,000 calories, which equates to an estimated daily intake of about 250 mg.”^11,12

You can use this study to tell your patients that magnesium has been shown to lower blood pressure in numerous clinical studies. And with other lifestyle interventions, dietary changes, and nutritional supplements, patients can often avoid antihypertensive medications, which in turn can cause magnesium deficiency.