How we rate
“Strong” = several concordant meta-analyses or systematic reviews. “Moderate” = one synthesis, or several controlled trials. “Limited” = early trials only. The rating is about the quality of the studies, not about how useful the supplement is.
Magnesium
A mineral whose intake slightly lowers blood pressure, improves blood sugar and helps elderly people sleep better.
Benefits
- Lowers blood pressure by 3 to 4 mmHg for systolic and 2 to 3 mmHg for diastolic, more above 370 mg per day (meta-analysis of 22 trials)
- Improves fasting blood sugar and insulin resistance, in both diabetics and at-risk individuals, after at least 4 months (meta-analyses)
- In elderly individuals with insomnia, lengthens sleep and shortens sleep onset
- In elderly women, 12 weeks improved chair rise and walking speed
Precautions
At high doses, laxative effect (especially oxide and sulfate forms). Caution in case of renal impairment.
Recommended dosage
Around 370 mg of elemental magnesium per day; the median dose in trials on blood pressure was 368 mg.
How to take it
- Dose: around 370 mg of elemental magnesium per day. In meta-analyses on blood pressure, the median dose was 368 mg, and the effect was clearer above 370 mg.
- How long: about 3 months for blood pressure; at least 4 months for fasting blood sugar and insulin resistance to clearly improve.
- Which form: positive trials exist with magnesium oxide, citrate, chloride and aspartate. No study in this profile compares them against each other.
- Deficient or not: it improved insulin sensitivity in individuals with low blood glucose magnesium, but also in overweight individuals with normal levels.
- During pregnancy: not enough solid evidence of a benefit, according to the Cochrane review of 10 trials.
Did you know?
Daily magnesium supplementation improves physical performance in healthy older women, such as the ability to stand up from a chair and walking speed.
What the studies say
This systematic review and meta-analysis evaluated the effect of oral magnesium supplementation on insulin sensitivity and glycemic control. The study found a significant effect of magnesium on the HOMA-IR index, a marker of insulin resistance. It was observed that magnesium supplementation of at least 4 months significantly improved the HOMA-IR index and fasting blood glucose in both diabetic and non-diabetic subjects.
Simental-Mendía LE, Sahebkar A, Rodríguez-Morán M, Guerrero-Romero F. — Pharmacological research (2016) — View the source study
For information only: not a substitute for medical advice. Dietary supplements are not a replacement for a varied, balanced diet. Learn more