Total, Dietary, and Supplemental Magnesium Intakes and Risk of All-Cause, Cardiovascular, and Cancer Mortality: A Systematic Review and Dose-Response Meta-Analysis of Prospective Cohort Studies.
Level 3 - non-randomized controlled study
Systematic review and meta-analysis of prospective cohort studies
PubMed 33684200 · doi:10.1093/advances/nmab001
What was done
A systematic review and random-effects dose-response meta-analysis searched PubMed, Scopus, Google Scholar, and ISI Web of Knowledge through April 2020. Prospective cohort studies reporting risk estimates for the association between dietary, supplemental, and total magnesium intake and all-cause, cardiovascular disease (CVD), or cancer mortality were included. The review pooled data from 19 publications comprising 1,168,756 participants followed for 3.5 to 32 years.
What was found
During follow-up, 52,378 all-cause, 23,478 CVD, and 11,408 cancer deaths occurred. Higher dietary magnesium intake was significantly associated with lower all-cause mortality (pooled ES: 0.87; 95% CI: 0.79, 0.97; P = 0.009; I² = 70.7%) and lower cancer mortality (pooled ES: 0.80; 95% CI: 0.67, 0.97; P = 0.023; I² = 55.7%), but not CVD mortality (pooled ES: 0.93; 95% CI: 0.82, 1.07; P = 0.313; I² = 72.3%). Supplemental and total magnesium intakes showed no significant associations with any mortality endpoint. In linear dose-response meta-analysis, each 100 mg/day increase in dietary magnesium was associated with a 6% reduction in all-cause mortality and a 5% reduction in cancer mortality.
Why it matters
This meta-analysis clarifies that mortality reductions associated with magnesium are specific to dietary intake rather than supplement use. This underscores the importance of whole-food dietary patterns over isolated mineral supplementation for long-term health outcomes.
Limits
The included studies are observational prospective cohorts, leaving findings susceptible to residual confounding by general diet quality and lifestyle factors. High heterogeneity was observed across studies for all-cause and CVD mortality (I² > 70%). Assessment of magnesium intake depended on self-reported dietary tools, which carry inherent measurement error.
Cited by
- supports A meta-analysis found that each additional 100 mg per day of dietary magnesium was associated with a 6% reduction in all-cause mortality and a 5% reduction in cancer mortality.
- supports A meta-analysis of three studies found a non-significant positive association between supplemental magnesium intake and cancer mortality risk.