Magnesium oxide use and reduced risk of dementia: a retrospective, nationwide cohort study in Taiwan.

Objective: Dietary magnesium may be associated with a lower risk of dementia; however, the impact of magnesium oxide (MgO), a common laxative, on dementia has yet to be elucidated. This study aimed to investigate the association between the usage of MgO and the risk of developing dementia.
Methods: We used a dataset from the National Health Research Institute Database (NHRID) of Taiwan containing one million randomly sampled subjects to identify patients aged ≥50 years with no history of MgO usage. A total of 1547 patients who had used MgO were enrolled, along with 4641 controls who had not used the MgO propensity score matched by age, gender and comorbidity, at a ratio of 1:3. After adjusting for confounding risk factors, a Cox proportional hazards model was used to compare the risk of developing dementia during a 10 year follow-up period.
Results: Of the enrolled patients, 44 (2.84%) developed dementia, when compared to 199 (4.28%) in the control group. The Cox proportional hazards regression analysis revealed that the patients who had used MgO were less likely to develop dementia with a crude hazard ratio of 0.617 (95% CI, 0.445-0.856, p = .004). After adjusting for age, gender, comorbidity, geographical area and urbanization level of residence, and monthly income, the adjusted hazard ratio was 0.517 (95% CI, 0.412-0.793, p = .001).
Conclusions: The patients who used MgO had a decreased risk of developing dementia. Further studies on the effects of MgO in reducing the risk of dementia are therefore warranted.