Dietary Magnesium and Cardiovascular Disease: A Review with Emphasis in Epidemiological Studies

2018
Nuria Rosique-Esteban, Marta Guasch-Ferré, Pablo Hernández-Alonso, and Jordi Salas-Salvadó

Abstract

Magnesium (Mg) is an essential dietary element for humans involved in key biological processes. A growing body of evidence from epidemiological studies, randomized controlled trials (RCTs) and meta-analyses have indicated inverse associations between Mg intake and cardiovascular diseases (CVD). The present review aims to summarize recent scientific evidence on the topic, with a focus on data from epidemiological studies assessing the associations between Mg intake and major cardiovascular (CV) risk factors and CVD.

We also aimed to review current literature on circulating Mg and CVD, as well as potential biological processes underlying these observations. We concluded that high Mg intake is associated with lower risk of major CV risk factors (mainly metabolic syndrome, diabetes and hypertension), stroke and total CVD. Higher levels of circulating Mg are associated with lower risk of CVD, mainly ischemic heart disease and coronary heart disease. Further, RCTs and prospective studies would help to clarify whether Mg intake and Mg circulating levels may also protect against other CVDs and CVD death.

Final Conclusions

Taken together, current evidence from epidemiological studies shows that higher Mg intake, either dietary or via supplementation, is associated with a protection against major CV risk factors, including MetS, T2D and hypertension/BP, as well as against stroke and total CVDs. Nevertheless, further prospective studies and RCTs are warranted to elucidate the relation between Mg intake and MetS individual components, endothelial dysfunction, lipid profile and obesity—of which current scientific knowledge remains very scarce—and HF, CHD and CVD death in different populations.

Available evidence on circulating Mg and CVDs shows that greater circulating [Mg2+] is also associated with lower risk of CVDs, mainly IHD and CHD, yet further insights are needed to clarify the less consistent results with other CVDs and CV death. Because Mg plays a crucial role in a wide range of biological pathways and outcomes, it is not surprising that alterations in Mg homeostasis may influence different disease status.

Importantly, the fact that Mg intake is determined using indirect methods in epidemiological studies, such as food frequency questionnaires, makes it difficult to separate the observed associations from those of other microelements that may also positively contribute to cardiometabolic health. Thus, a residual effect from the intake of other dietary microelements cannot be discarded despite the efforts for controlling this in multivariate models.

Traditionally, supplement formulations from organic Mg (aspartate, citrate, lactate and chloride) have been considered to be more bioavailable than those with inorganic Mg (oxide and sulfate), as reported by a number of studies [108]. However, this topic is currently under debate given that other studies have found no differences between these formulations, and several factors have been shown to play a role in the complex process of Mg absorption and utilization [109].

The inverse association between Mg intake and IR, hyperglycemia, dyslipidemia, hypertension, and markers of inflammation may justify the protective effect of dietary Mg on CVD. Overall, the current evidence supports the importance of adequate dietary magnesium for lowering CVD risk. In addition, these findings support the importance to increase the consumption of magnesium-rich foods, including fruits, vegetables, legumes, nuts and whole grains for the prevention of chronic diseases.