The human liver is a truly wonderful organ.
As the second-largest organ after the skin, the liver weighs around 1.5kg or approximately 2% of an adult’s body weight. It is an important organ that performs at least 500 functions in our body, such as1:
- Produces bile that aids in digestion
- Stores and metabolizes vitamins and minerals
- Metabolizes drugs and making toxins less harmful to the body
- Metabolizes fats, proteins and carbohydrates
- Activates enzymes
- Blood detoxification
- Produces blood proteins for blood clotting
Diseases associated with the liver are sometimes without symptoms. Patients often aware of the conditions when it has progressed in the late stage. Most of the time, it is only through the annual health check-up that patients are able to be informed of the abnormalities. Thus, a routine health screening or blood testing at least once a year is highly recommended for adults to keep track of overall well-being. Regular health screening can also help to identify health problems earlier and serve as a preventive measure for illnesses.
Varied on health screening packages provided by each laboratory services, the common blood testing includes blood count test, lipid profile check, thyroid screening test, diabetes screening test, renal and liver function tests. In this article, we will look into the liver function tests and understand what the result reflects your current liver conditions as well as the natural ingredients that are beneficial for maintaining a healthy liver.
The Standard Liver Function Tests
Take a look at your blood testing report. There are terms used under the liver profile which might look rather complicated to understand such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), bilirubin, albumin, to name a few.
These are the enzymes and proteins produced by the liver and released into the blood that can be used to analyse liver health conditions.
Alanine aminotransferase (ALT)
ALT is an enzyme found in the kidney, heart, muscle and liver. Elevated ALT levels indicate the presence of liver cell injury. This is due to excessive leakage of the enzyme from the damaged liver cells into the bloodstream.2 As the liver tissue contains a greater concentration of ALT than the other body tissues, the ALT test is more specific than the aspartate aminotransferase (AST) test in demonstrating the liver cell injury.3
The normal range of ALT level is 7-56 U/L.4 The value may differ depending on the techniques used by different laboratories. On the other hand, ALT level greater than 500 U/L is most often associated with liver health conditions such as4:
- Viral and autoimmune hepatitis
- Ischemic liver injury
- Toxin/drug-induced liver damage
Type II diabetes patients and pregnant women may also experience higher ALT level.5,6
Aspartate aminotransferase (AST)
The enzyme, AST is found in various parts of the body, including the heart, liver, muscle and kidney. Like ALT, the AST level indicates the possibility of liver cell injury. A damaged or inflamed liver cell causes AST to release into the bloodstream, thereby raised the AST level.
Normal serum AST is 0 to 35 U/L,4 though it may vary from different laboratories. Elevated AST levels might indicate liver health conditions such as below:
- Alcohol-related liver injury
The heart muscle contains a significant amount of AST. Hence, increased AST level can also link with heart health issues. To better evaluate liver conditions, the AST level is always measured together with the ALT level. Both AST and ALT levels will usually rise in conjunction to indicate liver cell injury.3
Alkaline phosphatase (ALP)
The ALP level is another standard liver test that assesses liver injury. ALP is found in the liver, kidney, small intestine, bone and placenta. The normal level of ALP is ranging from 41 to 133 U/L.4 Abnormal ALP level may indicate conditions either related to liver health or other non-liver health problems:
- Gallbladder inflammation
- Bile duct blockage
- Zinc deficiency
- Bone disorders
Despite the mentioned health concerns, there are also factors which contribute to abnormal ALP level. For example, elderly older than 60 years old, especially women, may have a mildly elevated ALP.7 Individuals with blood types O and B may also experience an increase in the ALP level, especially after a fatty meal.8 The increased in ALP level among children and adolescents is usually link to rapid bone growth, whereas the high ALP in pregnant mother is due to the influx of the enzyme in the placenta.7,9
Gamma glutamyl transferase (GGT)
The GGT enzyme is present in the liver, kidney, pancreas and intestine. The normal level of GGT is 9 to 85 U/L. A higher GGT level is usually associated with bile duct or liver diseases such as hepatitis and fatty liver disease. Other conditions that show high GGT level are uncomplicated diabetes mellitus, acute pancreatitis, heart health problems, anorexia nervosa and obesity.4 GGT test often assesses with the ALP test to rule out the possibility of bone diseases as GGT is not found in the bone.4
Bilirubin is a yellow pigment found in your blood due to the result of red blood cells breakdown.2 The liver processes bilirubin in the blood and turn it into bile to excrete it out of the body. Thus, the total bilirubin level has served as one of the standard tests to evaluate liver function. Normal total bilirubin ranges from 2 to 21µmol/L.4 Lower-than-normal levels of bilirubin are usually not a concern. However, high levels of bilirubin may indicate several health conditions such as:
- Blockage of bile duct
- Jaundice (yellowing of skin and whites of the eyes)
- Impaired liver function with disorders such as hepatitis, Dubin-Johnson Syndrome (a rare genetic liver disorder)
- Hemolysis (abnormal breakdown of red blood cells)
- Gilbert’s Syndrome (a mild liver disorder that affects the body’s ability to process bilirubin)
Albumin is a protein produced by the liver. It helps to keep fluid in the bloodstream so it doesn’t leak to other tissues. The albumin also plays an important role as a transporter of bilirubin, hormones, metals, vitamins and drugs in our body. The normal range of albumin is 3.5 to 5.0 g/dl (35 g/L to 50 g/L).10 An elevation in albumin level is usually related to acute dehydration. However, low albumin level raises suspicion for conditions such as:
- Protein malnutrition
- Intestinal malabsorption
- Nephrotic syndrome (a collection of symptoms that indicate kidney damage)
- Chronic infection
- Acute inflammation
The Vital Nourishments For Your Liver
Your liver is the only organ that can regenerate or repair by itself. The liver tissue possesses the ability to compensate for the lost tissue and restore to its full liver size after partial removal of the tissues and chemical injury.11 However, liver regeneration can be limited in an irreversible liver condition such as the cirrhotic liver.12
Routine monitoring of liver condition through health screening together with supplementation can help to prevent further liver damage and achieve optimal liver health.
Dandelion is a flowering plant native to the Northern Hemisphere. It is not only used in cuisines from all around the world but also widely used in traditional and herbal medicine for the management of high blood sugar level, high cholesterol level, digestive health, and inflammation as well as liver disorders. The active components in dandelion such as the polysaccharides, flavonoids, phenolic, tannins, ascorbic acids, taraxol, taraerol, laevulin, inulin, and luteolin are found to be responsible for its liver protective effects.13
Two studies that evaluated the effects of the dandelion root extract in alcohol-induced and radiation-induced liver tissue injuries showed that dandelion root extract possesses antioxidative potentials in reducing tissues damage. Both studies resulted in increasing antioxidant glutathione, as well as decreasing the levels of ALT, AST and ALP enzymes, which usually arise in the presence of liver injury.14,15 Besides, dandelion root extract is also found to provide the same protective action against drug-induced liver injury.16
Turmeric is a spice widely used in culinary, especially in Asian countries. The goodness of turmeric lies within its bioactive compound, known as curcumin. Due to its proven antioxidative and anti-inflammatory properties, curcumin has also been used as health supplements for the management of several ailments,17 including liver health issues.
A study that investigated the effects of curcumin on the non-alcoholic fatty liver disease (NAFLD) found that supplementation of 70mg curcumin for 8 weeks improved several features of NAFLD. This including reduced liver fat content, serum levels of AST and ALT, body mass index, total cholesterol and glucose level.18
When the build-up of liver fat causes inflammation, it can develop into non-alcoholic steatohepatitis (NASH), an advanced form of NAFLD. Curcumin can help to activate the antioxidation effect and block certain pathway in the body which is responsible for the inflammation of liver cells, thereby making curcumin a promising supplement in alleviating NASH.19
There is some evidence from animal studies shown that curcumin can be beneficial to liver cirrhosis.20,21 A 2007 study published in Liver International reported that rats fed with 300mg/kg of curcumin for 12 weeks showed reduced oxidative stress and inhibited the growth of carcinogen-induced liver cirrhosis mainly due to its anti-inflammatory effects.20
- Kalra A, Yetiskul E, Wehrle CJ, et al. Physiology, Liver. [Updated 2020 May 24]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK535438/
- Kasarala G, Tillmann HL. Standard liver tests. Clinical Liver Disease. 2016;8(1):13-18.
- Hall P, Cash J. What is the real function of the liver ‘function’ tests? Ulster Med J. 2012;81(1):30-36.
- Gowda S, Desai PB, Hull VV, Math AAK, Vernekar SN, Kulkarni SS. A review on laboratory liver function tests. Pan African Medical Journal. 2009;3:17.
- Bacq Y, Zarka O, Brechot JF, Mariotte N, Vol S, Tichet J, et al. Liver function tests in normal pregnancy: a prospective study of 103 pregnant women and 103 matched controls. Hepatology. 1996;23(5):1030-1034.
- Saligram S, Williams EJ, Masding MG. Raised liver enzymes in newly diagnosed type 2 diabetes are associated with weight and lipids, but not glycaemic control. Indian J Endocrinol Metab. 2012;16(6):1012-1014.
- Moss DW. Alkaline phosphatase isoenzymes. Clin Chem. 1982;28:2007-2016.
- Matsushita M, Komoda T. Relationship between the effects of a high-fat meal and blood group in determination of alkaline phosphatase activity. Rinsho Byori. 2011;59:923-929.
- Fishman WH, Bardawil WA, Habib HG, Anstiss CL, Green S. The placental isoenzymes of alkaline phosphatase in sera of normal pregnancy. Am J Clin Pathol. 1972;57:65-74.
- Busher JT. Serum Albumin and Globulin. In: Walker HK, Hall WD, Hurst JW, editors. Clinical Methods: The History, Physical, and Laboratory Examinations. 3rd edition. Boston: Butterworths; 1990. Chapter 101.Available from: https://www.ncbi.nlm.nih.gov/books/NBK204/
- Rmilah AA, Zhou W, Nelson E, Lin L, Amiot A, Nyberg SL. Understanding the marvels behind liver regeneration. Wiley Interdiscip Rev Dev Biol. 2019;8(3):e340.
- Horiguchi N, Ishac EJN, Gao B. Liver regeneration is suppressed in alcoholic cirrhosis: correlation with decreased STAT3 activation. Alcohol. 2007;41(4):271-280.
- Mahboubi M, Mahboubi M. Hepatoprotection by dandelion (taraxacum officinale) and mechanisms. Asian Pacific Journal of Tropical Biomedicine. 2020;10(1):1-10.
- You Y, Yoo S, Yoon HG, Park J, Lee YH, Kim S. In vitro and in vivo hepatoprotective effects of the aqueous extract from Taraxacum officinale (dandelion) root against alcohol-induced oxidative stress. Food Chem Toxicol. 2010;48(6):1632-1637.
- Abdel-Magied N, Fatteh SMA, Elkady AA. Differential effect of Taraxacum officinale L. (dandelion) root extract on hepatic and testicular tissues of rats exposed to ionizing radiation. Mol Biol Rep. 2019;46(5):4893-4907.
- Cai L, Wan D, Yi F, Luan L. Purification, preliminary characterization and hepatoprotective effects of polysaccharides from dandelion root. Molecules. 2017;22(9):1409.
- Hewlings SJ, Kalman DS. Curcumin: a review of its’ effects on human health. Foods. 2017;6(10):92.
- Rahmani S, Asgary S, Askari G, Keshvari M, Hatamipour M, Feizi A, et al. Treatment of non-alcoholic fatty liver disease with curcumin: a randomized placebo-controlled trial. Phytother Res. 2016;30(9):1540-1548.
- Lee DE, Lee SJ, Kim SJ, Lee HS, Kwon OS. Curcumin ameliorates non-alcoholic fatty liver disease through inhibition of O-GlcNAcylation. Nutrients. 2019;11(11):2702.
- Bruck R, Ashkenazi M, Weiss S, Goldiner I, Shapiro H, Aeed H, et al. Prevention of liver cirrhosis in rats by curcumin. Liver Int. 2007;27(3):373-383.
- Cai Y, Lu D, Zou Y, Zhou C, Liu H, Tu C, et al. Curcumin protects against intestinal origin endotoxemia in rat liver cirrhosis by targeting PCSK9. Journal of Food Science. 2017;82(3):772-780.