Researchers studied the magnesium intake of 4,365 patients over 12 years (including follow-up) and found an inverse association between mineral levels and CVD mortality.
A high magnesium intake of 322 mg per day was linked with a lower risk of CVD and all-cause mortality, and particularly among participants taking diuretics.
Based on current findings and previous evidence, the authors suggest that magnesium intake may be more strongly related to mortality risk in patients with cardiovascular disease than in the general population.
“Our findings underscore the importance of adequate magnesium intake in patients with cardiovascular disease, in addition to cardiovascular drug treatment,” The researchers wrote in Frontiers in Cardiovascular Medicine.
“The highest CVD mortality risks were observed for magnesium intake below median intake. Estimates of protective risk for CVD mortality were shown for magnesium intakes above adequate intake. “
The findings add to an ever-growing body of science that supports the mineral’s potential health benefits. The National Institutes of Health (NIH) lists magnesium as needed for more than 300 biochemical reactions in the body, from helping maintain normal muscle and nerve function, keeping heart rhythm steady, supporting a healthy immune system, and keeping strong bone. The mineral is also needed for blood sugar management and healthy blood pressure.
European experts recommend daily magnesium intake of 350 mg for men and 300 mg for women as adequate levels can help control blood glucose levels, blood pressure and myocardial metabolism.
Hypomagnesaemia can also lead to insulin resistance, impaired lipid metabolism, and impaired endothelial and renal function.
The requirements may differ for CVD patients who have undergone physiological changes in their cardiovascular system, are more prone to comorbidities, and who are taking medications that can interfere with absorption. Furthermore, the effects of magnesium intake on long-term mortality risks are unclear.
Current research then examined the relationship between dietary magnesium and CVD, all-cause mortality and CHD in patients with a previous myocardial infarction and who were taking medications.
Male and female participants with a mean age of 69 were selected from the cohort involved in the Alpha Omega study, where myocardial infarction patients were monitored for the effects of low-dose omega-3 fatty acids or a placebo. for 40 months.
Dietary intake was established with an FFQ that verified frequency, quantity, type of food, and methods of food and drink preparation. Supplement use was determined with a self-reported lifestyle and health questionnaire.
The questionnaire results determined that magnesium supplements were used by 235 (5.4%) of the patients and the average overall magnesium intake was approximately 300 mg / day.
Researchers adopted Cox proportional hazards models to assess the association between energy-adjusted magnesium intake and mortality risk factors and limited cubic splines (RSCs) to determine continuous and threshold associations.
Influence of diuretics
The results showed a direct link between magnesium status and lower CVD risk in both male and female participants. There was no significant associated link with magnesium intake and death from coronary heart disease (CHD).
The authors write that a 100 mg / day difference in magnesium intake correlates with a 30-40% lower risk of CVD and all-cause mortality in different subgroups.
They note that protective associations were more evident in the presence of diuretics and hypothesize that they may affect magnesium status by inhibiting sodium in the kidney and indirectly affecting magnesium absorption.
“Based on sensitivity analyzes by type of diuretics, we conclude that both thiazide diuretics and potassium-sparing diuretics may be involved in the relationship between magnesium intake and CVD mortality.” they wrote.
Effect of dietary fiber
The presence of dietary fiber rather than magnesium may also explain the inverse relationship with CVD mortality, the authors say, as both are derived from similar dietary sources and were highly correlated in the study.
Population-based studies have identified an association between dietary fiber and risks to CVD morality, however most of these did not correct magnesium, so the protective elements could be linked to both compounds, they argue.
In addition, the researchers conducted subgroup and sensitivity analyzes, which revealed inverse associations for magnesium in patients with low and high fiber intakes and in magnesium-depleted diuretics users..
“Based on the totality of the findings, we believe that taking magnesium regardless of fiber may have helped reduce the risk of CVD mortality in the Alpha Omega cohort.” they wrote.
Finally, they suggested that the study’s limitations should be considered in the context of the findings, given the observational nature of the study and the shortcomings of self-reporting – and despite adjustments for confounding elements, such as dietary and lifestyle factors.
Source: Frontiers in Cardiovascular Medicine
Published online, August 12, 2022: doi: 10.3389 / fcvm.2022.936772
“Dietary Magnesium and Risk of Cardiovascular and All-Cause Mortality After Myocardial Infarction: A Prospective Analysis in the Alpha Omega Cohort”
Author: I. Evers, et al.