Is magnesium L-threonate better for your brain?

Magnesium L-threonate (MgT) is distinguished from ordinary magnesium supplements by its apparent ability to raise magnesium levels in the brain more effectively. Other forms of magnesium are poorly absorbed across the blood-brain barrier; MgT crosses it more efficiently, which makes it biologically plausible that it could act specifically on brain function.

The clinical evidence in humans exists, but is limited. A double-blind, placebo-controlled study of 44 older adults (aged 50-70) with cognitive complaints found a statistically significant improvement in cognitive functioning compared with placebo after 12 weeks. The study was small, and effects on sleep and anxiety were indistinguishable from placebo. A second study (109 healthy Chinese adults) observed improved memory scores after 30 days, but that supplement contained phosphatidylserine, vitamin C and vitamin D in addition to MgT. The effect therefore cannot be attributed entirely to MgT alone.

In multiple mouse studies, MgT reduced the accumulation of harmful protein clusters associated with Alzheimer's disease, prevented the loss of connections between brain cells, and improved memory. This held true even in advanced Alzheimer's-like pathology. A previously published 2013 article on similar mouse research has been retracted due to unreliability; its findings are not counted here. The remaining mouse studies still stand, but translation to humans remains uncertain.

A magnesium deficiency is associated with a higher risk of depression, anxiety and cognitive decline. Whether supplementation actually reduces those risks has not been definitively proven. MgT appears mechanistically well positioned for brain effects, but large independent studies in humans are still lacking.