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GABA supplements and the blood brain barrier



Q: I’ve been told that GABA supplements do not cross the blood brain barrier (BBB), though other sources say that they do. Can you please tell me who’s right?

A: That’s a great question. To answer, we will need to get a bit scientific.

GABA (short for gamma-aminobutyric acid) is an amino acid that is made in the brain, and the chemical structure of GABA does not cross the BBB. Rather, GABA is a chemical messenger, or neurotransmitter, that provides a pathway within the brain. Certain receptors called GABAergic receptors are found throughout our brain.

Many scientists are exploring the gut-brain connection, and the mechanisms by which substances are exchanged between the BBB and the gut. Fermentation is thought to amplify nutritional components of foods, so it may logically follow that supplements sourced from fermented foods should provide more nutrition to the body, as well.

It should be noted that GABA is an amino acid, and absorption of supplemental GABA may depend on other amino acids—meaning, while one amino acid may improve GABA’s absorption, another may hinder it.

As well, due to factors like genetics and lifestyle, the biochemistry of some individuals may not contain the optimal combination of helpful nutrients. In these cases, it may be necessary to take complementary supplements along with their GABA.

As an example, L-lysine proportionally facilitates the brain’s production of GABA in the body. On the other hand, animal studies suggest that taurine and glycine may be blocked by GABA receptors in the brain, reducing the effectiveness of GABA supplements by competing for absorption.

In short, fermented supplements may have the means to cross the BBB, but only by way of the gut; think of it as taking the scenic route within the highway of the brain.



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Raise a glass and say cheers to not-so-hard drinks

Matthew Kadey, MSc, RDMatthew Kadey, MSc, RD