A diet of chicken, fish and protein shakes might do wonders for people with brain injuries.

Akiva Cohen of the University of Pennsylvania in Philadelphia and his colleagues mimicked brain injury in mice by injecting fluid through a hole drilled in their skull.

After seven days, the brain-injured mice had much lower levels of three branched-chain amino acids (BCAAs), leucine, isoleucine and valine, compared with control mice. These are found in protein-rich food and are known for their ability to build muscle.

The team then fed another set of brain-injured mice either plain water or water enriched with BCAAs. Five days later, those that had taken BCAAs had normal levels of the amino acids and performed better on a learning task.


Excitation disturbance

Cohen’s team reckon they might have figured out how the BCAAs are having this effect. In the hippocampus of a person with a brain injury, the delicate balance of neuronal excitation and inhibition is disturbed, says Cohen. The BCAAs may help restore the balance by making more neurotransmitters, he suggests.

The findings complement observations made by a group of Italian biochemists last year. Simona Viglio of the University of Pavia and colleagues found that minimally conscious patients who were given BCAAs intravenously improved in their “feeding, grooming and toileting” abilities.

“The new findings represent a substantial progression because they provide evidence, on an experimental basis, of the beneficial effects of BCAAs,” says Viglio.

Cohen’s group will now look at the effects of BCAAs on other areas of the brain, and are hoping to start human trials of amino acid-based treatments soon.

“In the near future, BCAA administration in humans could become a routine treatment,” says Viglio.

Journal reference: Proceedings of the National Academy of Sciences, DOI: 10.1073/pnas.0910280107