Liver function test: What is it and what does it reveal?

Looking at the liver from a body-mind perspective, the liver — or should that be LIVE-r? — is the organ viewed as the seat of anger and primitive emotions. The many sayings around the liver make one wonder how much our ancestors knew about the body: “She is so full of bile” or “I was so angry I could feel my bile rise”. 

The quote by William James, “Is life worth living? It all depends on the liver”, is a nice play on the importance of the liver in our lives.

It is quite common to do a liver function test when checking general health. When you have digestive, weight or hormonal issues, or when taking certain chronic medications, such tests can be done more frequently. But what does a liver function test look for and what do the results mean?

Elevated levels of liver enzymes some cause for concern

It is worth noting that elevated levels can be influenced by normal physiological changes in the body and that the amount of elevation also plays a role in the interpretation of the results. This is also why your doctor will explain and interpret it for you.

In a liver function test different aspects of the liver is tested, so breaking it up in the groups tested for makes it easier to understand. When looking at liver function test analyses, abnormalities can be divided into three main patterns.

1. Hepatocellular (involving liver cell) pattern: Related to disproportionate elevation in AST+ALT in relation to alkaline phosphatase (possible causes are alcohol abuse, drugs, non-alcoholic fatty liver disease, viral hepatitis);
2. Cholestatic (bile flow interference) pattern: Related to disproportionate elevation in alkaline phosphatase in relation to AST+ALT (possible causes could be gallstones, drugs and cancer); and
3. Isolated Hyperbilirubinaemia (impaired bilirubin transport after conjugation): Elevated bilirubin levels with normal AST+ALT and alkaline phosphatase (possible causes could be viruses, alcohol and autoimmune disorders).

Liver ABC’s: Telling your AST’s apart from your ALT’s

A healthy liver is vital for overall physical health. Image: Adobe Stock

The aminotransferases AST (aspartate aminotransferase) and ALT (alanine aminotransferase) help in the recognition of liver cell diseases and injury. When checking for hepatitis (a disease that causes inflammation of the liver) your doctor will look closely at these two readings.

ALT is an enzyme (a protein that brings about biological changes) in the liver that helps convert proteins into energy for the liver. An increase could mean liver damage. AST is an enzyme that helps metabolise amino acids (breakdown and removal of ammonia). An increase could mean liver damage, liver disease or muscle damage.

The role of other liver enzymes

Alkaline phosphatase ALP is an enzyme found in the liver and bone that breaks down proteins. An increase could mean liver damage or disease, a blocked bile duct or bone disease.

Albumin and Total Protein: Albumin is a protein made in the liver. Reduced levels of albumin and total protein may indicate liver damage or disease.

Bilirubin is produced by the normal breakdown of red blood cells. After passing through the liver it is excreted in the stool. Increased levels might indicate liver damage, liver disease or anaemia.

Gamma-glutamyltransferase (GGT) is a enzyme found in the blood that, when elevated, may indicate liver damage and bile duct damage. L-lactate dehydrogenase (LD), on the other hand, is an enzyme found in the liver which may indicate liver damage.

Prothrombin time (PT) is the time it takes for your blood to clot. If it is increased you could have liver damage, but it can also be because of blood thinning medications.

How to keep your liver healthy

The liver can be affected by lifestyle choices, drug use (both prescribed and recreational), viruses, bacteria and toxins in the environment. There is not a one-size-fits-all answer.

There are certain factors that will improve general liver health and that is what you can pursue. Losing weight if necessary, moderate exercise, managing diabetes and a healthy diet with a large percentage being plant-based with good fats and whole grains, reducing caffeine and avoiding alcohol are all worth pursuing.

Holistic treatments for liver issues

Ginger and beetroot can nutritionally aid the liver. Image: Adobe Stock

Holistic approaches need to be tailored by the specifics of the liver issue and, as always, speaking with your primary healthcare practitioner is essential in the total management of your condition.

The colour yellow supports stomach and liver function. Herbs and supplements can, depending on your liver condition, cause aggravation, and thus need to be taken with care. Herbs like dandelion, milk thistle, artichoke leaf, tumeric root and yellow dock root can be considered.

Foods like ginger and beetroot, green tea, blueberries, cranberries and prickly pears contain liver-supporting compounds. Supplements to support a healthy liver include Vitamins A,D,E and B12, and the micronutrient Molybdenum.

ALSO READ: Fatty liver disease: What it is and what you can do to manage it