Before we dive into the fascinating ways that amino acids benefit liver health, let’s provide some context on just how dire the consequences of not paying attention to the health of your liver can be.
There are more than 4.9 million diagnosed cases of chronic liver disease in the United States, based on statistics shared by the Centers for Disease Control and Prevention (CDC). Of those cases, 40,545 end in death.
According to the American Liver Foundation, “Anything that keeps your liver from doing its job may put your life in danger.” There are many different factors that can interfere with liver function, such as…
- A viral infection
- Chemical injury
- A misfiring immune response
Regardless of the underlying cause, the central danger is the same: that your liver will become too damaged to function at the level necessary for you to remain alive. And no matter what set it off, liver damage and disease tends to progress along a familiar path.
What Causes Liver Disease?
One of the factors that spurs the progression of liver disease is that a protein called Bcl-xl begins to malfunction, failing to control the release of a second protein called cytochrome C, which occurs when a liver cell dies.
The release of cytochrome C triggers a cascade reaction in the liver which ultimately results in liver scarring—what medical professionals refer to as “hepatic fibrosis”—and instigates the development of chronic liver disease.
When it comes to uncovering methods for preventing liver disease and protecting the health of the liver, finding ways to ensure the Bcl-xl protein functionally regulates cytochrome C is a major priority. And exciting new research indicates that branched-chain amino acids (BCAAs) may be able to do exactly that.
In order to understand how amino acids protect your liver, it’s important to understand how the liver processes amino acids.
How the Liver Processes Amino Acids
Did you know that your liver is the largest organ in your body? Given that, it’s hardly surprising how many essential functions the liver carries out. Not only does your liver detoxify your blood, but it also processes nutrients and produces lipids, carbohydrates, and amino acids.
Your liver produces a variety of proteins, such as albumin and fibrinogen, two of the major plasma proteins that are responsible for many vital tasks. Albumin keeps your blood volume balanced and transports essential amino acids throughout the body, while fibrinogen ensures your blood clots properly.
One of the primary functions of the liver is to process the amino acids your body absorbs through protein digestion. Your liver uses enzymes called deaminases and transaminases to transform the amino acids into the forms most useful to your body.
The deaminase and transaminase enzymes can add nitrogen to synthesize nonessential amino acids, or remove nitrogen to leave intact carbon structures that can then be utilized for the production of glucose or, less frequently, converted into fatty acids.
When these processes involve the release of nitrogen, a potentially toxic compound called ammonia is generated. Your liver then converts the ammonia to urea, allowing it to be safely flushed from your body.
Prolonged, excessive exposure to alcohol or other drugs as well as nutritional deficiencies can compromise your liver’s ability to carry out these key jobs. Altered amino acid metabolism is one of the hallmark symptoms of liver disease, and studies indicate that supplementing with amino acids—and BCAAs in particular—can improve the health of your liver.
Investigating the Ways Amino Acids Benefit Liver Health
Some of the most exciting research on how amino acids benefit liver health was done by a team of scientists based in Kyoto, Japan. The team hypothesized that BCAA supplementation could slow down, or possibly even halt, the progression of chronic liver disease.
After inducing liver disease in a group of rats, the researchers then split the rats into two groups. One group received a diet supplemented with three BCAAs: valine, leucine, and isoleucine. The other was the control group. Over the course of the 11-week study, weekly blood samples were taken from both groups of rats. At the study’s conclusion, the researchers took liver samples.
The results of BCAA supplementation were quite dramatic. Blood levels of a liver enzyme called AST, which rises as liver damage intensifies, were an average of 22% lower for the group given BCAAs than for the control group. And levels of the CTGF protein, a marker of liver scarring, were an average of 75% higher in the control group.
Perhaps most significant of all, levels of an enzyme called caspase 3 and a protein called albumin, which indicate rates of cell death, were respectively 100% and 80% higher in the control group.
Based on these changes, the researchers concluded: “Supplementation with branched-chain amino acids delays the progression of chronic liver disease” and that it does so specifically by slowing liver cell death.
Rates of Liver Disease Are Rising
Concerningly, rates of liver disease fatalities in the United States are rising, according to an analysis of data collected from across the nation. Lead author Zobair M. Younossi, MD, MPH, attributes this largely to a spike in nonalcoholic fatty liver disease (NAFLD).
“I believe it’s all related to a big increase in obesity and type 2 diabetes in this country,” Dr. Younossi said in an interview in advance of the annual meeting of the American Association for the Study of Liver Diseases. “Those two risk factors drive NAFLD and its progressive type, nonalcoholic steatohepatitis (NASH). That accounts for at least part of the increase in mortality related to liver disease.”
Dr. Younossi and his colleagues analyzed findings from 838,809 chronic liver disease-related deaths. They found that the overall fatality rate for chronic liver disease rose by 1.3% for men and 2.5% for women.
Nonalcoholic liver disease was the most common cause of chronic liver disease-related deaths (34.7%), followed by alcoholic liver disease (28.8%) and chronic hepatitis C (21.1%). Between 2007 and 2016, fatalities caused by NAFLD increased from 7.6 to 9.0 per 100,000.
One of the most important takeaways from the analysis, Dr. Younossi said, is that NASH—the most severe form of NAFLD—is quite common in the United States. “These patients are under-recognized and underdiagnosed because they are asymptomatic.” But fatty liver disease can progress to full-blown cirrhosis. Younossi believes it’s vital to identify treatments that can help to tackle this disease.
Using Amino Acids to Treat Liver Disease
Studies done with humans have confirmed that amino acid supplements can naturally and effectively treat both nonalcoholic fatty liver disease and alcoholic liver disease, the top two causes of liver disease-related deaths.
A clinical trial found that essential amino acids reduce liver fat as effectively as fenofibrate, a top pharmacological treatment. And the amino acids caused no adverse reactions. Fenofibrate, on the other hand, can cause unpleasant side effects such as fever, hives and other skin rashes, muscle aches and pains, stomach pain, and vomiting.
Scientists are still working to understand the metabolic shifts that cause fat to accumulate in the liver, which then disrupts liver function and results in damage and disease. Many people show no symptoms of fatty liver in the early phases, but some potential warning signs include:
- Difficulty concentrating
- Pain in the upper right abdomen, where the liver is located
It is possible to mitigate the damage associated with fatty liver disease, and in some cases, to fully reverse it. Nutrient therapies that improve fatty acid metabolism in the liver, like essential amino acids, can go a long way toward safeguarding or restoring liver health.