Magnesium Intake, Quality of Carbohydrates, and Risk of Type 2 Diabetes: Results From Three U.S. Cohorts

Abstract

OBJECTIVEMagnesium intake is inversely associated with risk of type 2 diabetes in many observational studies, but few have assessed this association in the context of the carbohydrate quality of the diet. We hypothesized that higher magnesium intake is associated with lower risk of type 2 diabetes, especially in the context of a poor carbohydrate–quality diet characterized by low cereal fiber or high glycemic index (GI) or glycemic load (GL).RESEARCH DESIGN AND METHODSIn the Nurses’ Health Study (NHS; 1984–2012, n = 69,176), NHS2 (1991–2013, n = 91,471), and the Health Professionals’ Follow-Up Study (1986–2012, n = 42,096), dietary intake was assessed from food frequency questionnaires every 4 years. Type 2 diabetes was ascertained by biennial and supplementary questionnaires. We calculated multivariate hazard ratios (HRs) of magnesium intake and incident diabetes, adjusted for age, BMI, family history of diabetes, physical activity, smoking, hypertension, hypercholesterolemia, GL, energy intake, alcohol, cereal fiber, polyunsaturated fats, trans fatty acids, and processed meat, and we considered the joint associations of magnesium and carbohydrate quality on diabetes risk.RESULTSWe documented 17,130 incident cases of type 2 diabetes over 28 years of follow-up. In pooled analyses across the three cohorts, those with the highest magnesium intake had 15% lower risk of type 2 diabetes compared with those with the lowest intake (pooled multivariate HR in quintile 5 vs. 1: 0.85 [95% CI 0.80–0.91], P < 0.0001). Higher magnesium intake was more strongly associated with lower risk of type 2 diabetes among participants with high GI or low cereal fiber than among those with low GI or high cereal fiber (both P interaction <0.001).CONCLUSIONSHigher magnesium intake is associated with lower risk of type 2 diabetes, especially in the context of lower carbohydrate–quality diets.

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

“…Previous meta-analyses evaluating Mg intake and T2D have also found consistent inverse associations [ 14 , 15 ]. More recently, a large prospective cohort study including more than 200,000 participants followed for over 28 years from the Nurses’ Health Study (NHS) I, NHS II and Health Professionals’ Follow-up study (HPFS) showed that, in pooled analysis across the three cohorts, those with the highest Mg intake (intake ranging from 350 to 500 mg/day) had 15% lower risk of T2D compared to those in the lowest Mg intake group (Hazard Ratio (HR) in the highest vs. the lowest quintile: 0.85 (95% CI 0.80–0.91)) [ 16 ]. This evidence has been further confirmed by clinical trials on Mg supplementation indicating beneficial effects of Mg on markers of glucose and insulin metabolism in individuals with and without T2D [ 17 , 18 , 19 ].…”

Intracellular free magnesium concentration in healthy horses

“…Diabetes mellitus type 2 patients often exhibit a magnesium deficit in the serum or at the cellular level. Hruby et al (2017) showed an inverse relationship between serum magnesium concentration and the incidence of diabetes mellitus type 2. Patients with a high magnesium intake had a 15% lower risk to develop diabetes mellitus type II (Hruby et al, 2017).…”

“…Hruby et al (2017) showed an inverse relationship between serum magnesium concentration and the incidence of diabetes mellitus type 2. Patients with a high magnesium intake had a 15% lower risk to develop diabetes mellitus type II (Hruby et al, 2017). Total serum magnesium concentration as well as the ionized serum magnesium fraction is reduced in 2,539% of diabetes patients (Lima et al, 2009;de Valk, 1999).…”

Influence of Demographic and Lifestyle Variables on Plasma Magnesium Concentrations and Their Associations with Cardiovascular Risk Factors in a Mediterranean Population

“…Among those observational studies, much research has been undertaken on whether there exists a relationship between magnesium contribution through dietary food and different cardiovascular risk factors, diabetes and cardiovascular diseases [38]. Thus, some studies have reported inverse associations between dietary magnesium intake and body mass index (BMI) or obesity [39,40], blood pressure [40,41], total cholesterol/LDL-cholesterol concentrations [42], and fasting glucose or type-2 diabetes [41,43,44], but the overall consistency for some of these factors is still low. Regarding the incidence of cardiovascular diseases, some studies have reported that high magnesium intake is associated with a lower risk of stroke, heart failure and total cardiovascular events [45,46], but less agreement has been observed for other cardiovascular events [38,47].…”