Association between magnesium intake and depression and anxiety in community-dwelling adults: the Hordaland Health Study

Objective: Systemic inflammation is associated with both the dietary intake of magnesium, and depression. Limited experimental and clinical data suggest an association between magnesium and depression. Thus, there are reasons to consider dietary magnesium as a variable of interest in depressive disorders. The aim of the present study was to examine the association between magnesium intake and depression and anxiety in a large sample of community-dwelling men and women. This sample consisted of 5708 individuals aged 46-49 or 70-74 years who participated in the Hordaland Health Study in Western Norway. Methods: Symptoms of depression and anxiety were self-reported using the Hospital Anxiety and Depression Scale, and magnesium intake was assessed using a comprehensive food frequency questionnaire. Results: There was an inverse association between standardized energy-adjusted magnesium intake and standardized depression scores that was not confounded by age, gender, body habitus or blood pressure (beta = -0.16, 95% confidence interval (CI) = -0.22 to -0.11). The association was attenuated after adjustment for socioeconomic and lifestyle variables, but remained statistically significant (beta = -0.11, 95% CI = -0.16 to -0.05). Standardized magnesium intake was also related to case-level depression (odds ratio (OR) = 0.70, 95% CI = 0.56-0.88), although the association was attenuated when adjusted for socioeconomic and lifestyle factors (OR = 0.86, 95% CI = 0.69-1.08). The inverse relationship between magnesium intake and score and case-level anxiety was weaker and not statistically significant in the fully adjusted models. Conclusion: The hypothesis that magnesium intake is related to depression in the community is supported by the present findings. These findings may have public health and treatment implications.