What is the proposed theory behind using BCAAs in hepatic encephalopathy?

• A. Increased aromatic amino acids relative to BCAAs due to muscle breakdown, leading to false neurotransmitters.
• B. Decreased aromatic amino acids with increased BCAAs.
• C. BCAAs are elevated and AAA reduced, improving encephalopathy.
• D. Amino acid ratios have no impact on encephalopathy.

Answer: (A)

The idea is that hepatic encephalopathy arises in part from an imbalance of amino acids in the blood: aromatic amino acids rise relative to branched-chain amino acids. This shift is amplified by factors like muscle breakdown releasing amino acids. The excess aromatic amino acids can cross into the brain via the same transporter used by branched-chain amino acids and are metabolized into compounds that resemble neurotransmitters, contributing to the neuropsychiatric symptoms of HE. By administering branched-chain amino acids, you help rebalance the plasma ratio, increase competition at the transporter, and reduce brain entry of aromatic amino acids, which may lessen the production of those neuroactive, false neurotransmitters. This concept explains why the ratio matters and why BCAA therapy is used.