The association between dietary magnesium (Mg) intake and the risk of atherosclerotic cardiovascular disease (ASCVD) remains uncertain. We aimed to examine the associations of dietary Mg intake with the risk of ASCVD events and mortality in individuals with and without type 2 diabetes.

A total of 149,929 participants (4603 with type 2 diabetes) from the UK Biobank were included in the analyses. The hazard ratios (HRs) and 95 % confidence intervals (CIs) were estimated using Cox proportional hazard models. Furthermore, interactions of dietary Mg intake with type 2 diabetes status were examined on multiplicative and additive scales.

During a median follow-up of 12.0 and 12.1 years, 7811 incident ASCVD events and 5000 deaths (including 599 ASCVD deaths) were documented, respectively. There were significantly negative associations between sufficient dietary Mg intake (equal to or greater than the recommended daily intake) and the risk of ASCVD incidence (HR 0.63 [95 % CI 0.49;0.82]), ASCVD mortality (0.45 [0.24;0.87]), and all-cause mortality (0.71 [0.52;0.97]) in participants with type 2 diabetes, whereas no significant association was observed in participants without type 2 diabetes (1.01 [0.94;1.09] for ASCVD incidence; 1.25 [0.93;1.66] for ASCVD mortality; 0.97 [0.88;1.07] for all-cause mortality). Multiplicative and additive interactions of dietary Mg intake with type 2 diabetes status were both observed.

Sufficient dietary Mg intake was significantly associated with lower risks of ASCVD events and mortality in individuals with type 2 diabetes but not in those without type 2 diabetes. Our findings provide insight into the importance of dietary Mg intake for reducing modifiable cardiovascular burden in individuals with type 2 diabetes, which may inform future personalized dietary guidelines.