Under a doctor's supervision, supplementing with branched-chain amino acids may correct an imbalance of amino acids and improve cirrhosis symptoms.
In addition to protein deficiency, liver cirrhosis is characterized by low blood levels of (BCAAs) in relation to other amino acids. This imbalance may contribute to the development of PSE. BCAA supplementation could be a way to correct this problem, as well as to provide a source of needed protein, but its effectiveness is unclear. BCAAs (isoleucine, leucine, and valine) represent a good protein source for people with cirrhosis because they are less likely to induce PSE. A controlled study of protein-intolerant people with cirrhosis showed that BCAA supplementation corrected abnormal protein metabolism about as well as an equivalent amount of dietary protein without inducing PSE as frequently. In a small double-blind trial, people with liver cirrhosis taking 5 grams per day of BCAAs had significant improvement in their ability to process protein.
However, treatment trials using BCAAs alone or in solutions containing other amino acids in people with cirrhosis and PSE have reported conflicting results. It may be that certain people with liver cirrhosis can benefit from supplementation with BCAAs while others cannot, for reasons that are unclear. In a double-blind trial, people with liver cirrhosis and PSE received 0.24 grams per 2.2 pounds body weight (approximately 16–17 grams per day) of BCAAs for 15 days, after which most experienced significant improvement in brain function, mental status, and protein metabolism. Those who continued taking BCAAs for three months also had mild improvement in liver function tests.
Therapeutic effects of oral BCAAs have also been shown in children with liver failure and in adults with cirrhosis of the liver without PSE. Overall, it appears that BCAA supplementation does not always help in cirrhosis, but some people with and without PSE may benefit. A qualified doctor must closely supervise such BCAA supplementation.