A new study reveals that higher dietary magnesium (Mg) intake is associated with better brain health, particularly in women. Researchers examined the association between dietary Mg and brain volumes and white matter lesions (WMLs) in middle to early old age. The findings were published in the European Journal of Nutrition.
The study included participants aged 40–73 years from the UK Biobank. Researchers used an online computerized 24-hour recall questionnaire to estimate daily Mg intake. They then investigated the association between baseline dietary Mg, Mg trajectories, and brain volumes and WMLs. They controlled for health and socio-demographic covariates and explored possible interactions between menopausal status and Mg trajectories.
Results showed that on average, higher baseline dietary Mg intake was associated with larger brain volumes (grey matter, left hippocampus, and right hippocampus) in both men and women. Latent class analysis of Mg intake revealed three classes: “high-decreasing”, “low-increasing”, and “stable normal”. In women, only the “high-decreasing” trajectory was significantly associated with larger brain volumes compared to the “normal-stable”. The “low-increasing” trajectory was associated with smaller brain volumes and larger WMLs.
The study found no significant associations between Mg and blood pressure (BP) measures. The neuroprotective effect of higher dietary Mg intake in the “high-decreasing” trajectory appears to be greater in post-menopausal than pre-menopausal women.
Higher dietary Mg intake was related to larger brain volumes and lower WMLs, indicating better brain health. The study hypothesizes that long-term exposure to dietary Mg, over years or decades, underlies the observed difference in brain ageing. This is consistent with studies showing that underlying neuropathological mechanisms develop over long periods, often during or before mid-life.
The seemingly neuroprotective effect of Mg was substantial and varied across brain regions, particularly strong for grey matter and the hippocampus. The study suggests that a 41% increase in Mg intake may lead to significantly better brain health, contributing to greater preservation of cognitive ability and lower risk or delayed onset of dementia in later life.
Research in mice has shown that Mg deficiency is linked to microglia activation and the production of pro-inflammatory cytokines, while Mg supplementation has an anti-inflammatory effect, increasing neurogenesis in the hippocampus. These effects may lead to reduced neurodegeneration in humans, but the impact on brain health may not be detected until later in life.
This study provides new evidence that higher dietary Mg intake is related to better brain health in the general population. Further research on the benefits of dietary Mg is needed to support possible population health interventions aimed at mitigating age-related neurodegeneration.