Magnesium L-Threonate and the Blood-Brain Barrier
- February 22, 2022
If you’ve been reading about magnesium supplements for improving cognitive function, you may have heard rumors that only magnesium L-threonate passes through the blood-brain barrier.
Some supplement manufacturers have even gone so far to dub magnesium L-threonate as “brain magnesium,” claiming that it is the sole form of that can help with memory, depression, anxiety, and chronic brain diseases – but that’s just not true.
There are many high-quality (and not so high-quality) magnesium products on the market. When it comes to choosing a magnesium supplement, however, things can get a little puzzling.
It’s easy to fall victim to marketing gimmicks.
Magnesium and Brain Function
Magnesium is one of many essential minerals that has multiple biological roles in the human body.
The nutrient is of particular importance for brain function; it has been shown to exhibit neuroprotective effects by combatting excessive excitation and death of neurons.
Several human studies have demonstrated that magnesium plays a key role in the regulation of stress response. It is likely that stress increases magnesium loss, causing deficiency.
In turn, magnesium deficiency could enhance the body’s susceptibility to stress. I should note that symptoms of magnesium deficiency and stress are very similar: fatigue, irritability, mild anxiety, etc.
58% of individuals with sleep disorders have been shown to consume less than the recommended intake of magnesium and they also exhibit higher levels of C-reactive protein, an indicator of inflammatory stress.
Low magnesium levels cause inflammation in the human body, which is associated with many chronic disease states, including several cognitive-related disorders.
Magnesium L-Threonate vs. Other Magnesium Salts
Magnesium L-threonate is a unique compound that is efficiently absorbed due to the bonding of threonic acid (a sugar compound derived from vitamin C).
I’ll admit – magnesium L-threonate is great at crossing the blood-brain barrier and increasing the body’s magnesium levels. Old and new studies have shown us that.1
However, many brands are making misleading claims of being the only form that can cross that barrier and provide the best cognitive benefits. Let’s set the record straight.
Most common forms of magnesium including citrate, oxide, chloride, and taurate have been shown to cross the blood-brain barrier and exhibit neuroprotective effects on cognition.
Human studies of head injury have consistently demonstrated this finding for decades. Rodent studies also report that various forms of magnesium can raise brain magnesium levels.
So don’t fall victim to marketers. Magnesium glycinate does not seem to cross the blood-brain barrier, but it still provides high levels of absorption and bioavailability, making it an option for correcting magnesium deficiencies.
The Bottom Line
Many forms of magnesium can cross the blood-brain barrier and influence cognitive outcomes. Consuming magnesium-rich foods is important because they contain a package of many nutrients and bioactives that work together to promote a wide variety of cognitive and other health benefits.
So, if you’re reading stuff online about how there’s only one magnesium supplement worth taking for neurological purposes, be skeptical.
There are lots of low-quality products out there. If you’re taking a supplement, be sure to read the Supplement Facts Panel to see how much magnesium is in the product, as marketing claims on the label can be deceiving (see example below).
Consider having your free ionized magnesium (iMg2+) levels checked to better understand your status. This will give you a better place to start as you talk to your dietitian or health professional about a magnesium supplement regimen that is right for you.