Branched chain amino acids ameliorate cognitive losses associated with brain injury.

Approximately 1.5 million people living in the United States experience a traumatic brain injury (TBI) – a disruption in normal brain function caused by an external mechanical force – each year. TBI causes both acute and chronic effects, including cognitive dysfunction. Findings from a 2009 study suggest that a branched chain amino acid-rich supplement ameliorates TBI-associated cognitive dysfunction.

The branched chain amino acids, which include leucine, isoleucine, and valine, play important roles in muscle protein synthesis. However, they also influence brain health because they contribute nitrogen molecules essential for neurotransmitter synthesis (particularly glutamate and gaba) and modulate brain neurochemistry.

The investigators measured branched chain amino acid concentrations in the brains of mice that had experienced a brain injury. Then they provided branched chain amino acids in the drinking water of brain-injured and non-injured mice for five days, commencing on the second day post-injury. Finally, they subjected both groups of mice to cognitive performance tests.

They found that brain concentrations of branched chain amino acids were markedly lower in the brain-injured mice, resulting in decreased function in the hippocampus, an area of the brain involved in learning. However, brain-injured mice that received the amino acids exhibited higher amino acid concentrations in their brains and better performance on cognitive tests.

These findings suggest that branched chain amino acids restore aspects of brain neurochemistry and ameliorate cognitive losses after TBI. Some bioactive compounds in plants may be beneficial in managing the symptoms of TBI, including sulforaphane, a compound derived from broccoli, which increases brain glutathione concentrations. Learn more in this clip featuring Dr. Rhonda Patrick.

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