~ by Jo Jordan
Weighing in at around three pounds, the liver functions as a unique organ with many crucial roles to sustaining life. From circulation to digestion, the liver continuously processes the blood used by the rest of the body.
Our largest internal organ, the liver works to keep us healthy. It converts food into substances needed for life and growth, storing glycogen (a blood-sugar regulator), amino acids, protein, and fat. It also makes the enzymes and bile that help to digest food.
In addition, the liver neutralizes harmful toxins and wastes, so it is at great risk of contamination from environmental toxins and those contained in over-processed foods.
Over 500 liver functions, including:
- Assimilating and storing fat-soluble vitamins
- Creating bile
- Filtering blood
- Metabolizing fats, proteins, and carbohydrates
- Metabolizing hormones, internally-produced wastes, and foreign chemicals
- Producing urea (a primary waste product, flushed from the body in urine)
- Purifying and clearing waste products, toxins, and drugs
- Regulating and secreting substances important to maintaining body functions and health
- Storing important nutrients (such as glycogen glucose), vitamins, and minerals
- Synthesizing blood proteins
While the liver is capable of regenerating itself, its capacity to repair itself can be seriously impaired by repeated or extensive damage.
Liver function tests
Often in the initial stages, diseases of the liver result in very mild symptoms and in some cases, none at all. For this reason in certain instances, liver function tests are performed to detect, evaluate, and monitor liver disease or damage.
Early detection of liver disease is vital to recovery. If you are at risk for liver disease, take medication that may cause liver damage, or have symptoms of liver disease, your physician may suggest testing.
Liver function tests (also known as LFTs or LFs) include liver enzyme readings. A single blood sample may include liver function testing for the following1:
- Alanine transaminase (ALT): An enzyme that helps metabolize protein. When the liver is damaged, ALT is released in the bloodstream.
- Alkaline phosphatase (ALP): An enzyme needed in small amounts to trigger specific chemical reactions. Normally present in the liver, bone, kidney, and intestine, higher than normal levels may indicate liver damage or disease.
- Aspartate transaminase (AST): This enzyme plays a role in the metabolism of the amino acid alanine. An increase in AST levels may indicate liver damage or disease.
- Albumin and total protein: Levels of albumin – a protein made by the liver – and total protein indicate how well the liver is making the proteins needed to fight infections and perform other functions. Lower than normal levels may indicate liver damage or disease.
- Bilirubin: A bi-product from the breakdown of red blood cells, bilirubin normally passes through the liver and is excreted in stool. Elevated levels – manifested as jaundice – may indicate liver damage or disease.
Additional tests that may be used to evaluate liver function include2:
- Gamma-glutamyl transferase (GGT): This test measures the amount of the enzyme GGT in the blood. Higher than normal levels may indicate liver or bile duct injury.
- Lactate dehydrogenase (LDH): An enzyme found in many body tissues, elevated levels of LDH may indicate liver damage.
- Prothrombin time (PT): This test measures the clotting time of plasma. Increased PT may indicate liver damage.
For more information on liver functions and how to care for your liver, please review the liver cleanse article.