What is liver disease?
The liver is the second largest organ (after the skin) in the body, located under the right ribcage in the upper abdomen. The liver performs several vital functions1,2, such as removing toxins from the blood, storing vitamins and minerals, regulating blood clotting and amino acids, and processing glucose. The liver also produces bile, an emulsifier that helps enzymes digest fats and carries away waste.
Liver disease is an umbrella term for several conditions that affect and damage the liver. Diseases affecting the liver can lead to cirrhosis (scarring). As scarring continues, the scar tissue replaces more healthy liver tissue, causing faulty liver function.1,2 The longer the liver disease goes untreated, the higher chance of liver failure and liver cancer.1,2
Causes of liver disease
- Consuming too many toxins: the misuse and abuse of alcohol can lead to alcohol-related fatty liver disease (ARLD) while consuming too much fat can cause non-alcoholic fatty liver disease (NAFLD)
- Viral infections: types of hepatitis (B, C, D, and E) are viral infections in the blood that affect liver functioning by causing inflammation
- Immune system problems: when the immune system mistakenly attacks the liver cells, it causes autoimmune liver diseases. Examples include primary biliary cholangitis and autoimmune hepatitis
- Inherited diseases: some liver conditions, such as Wilson disease and hemochromatosis, are inherited
- Cancer: the development of abnormal cells in the liver can cause tumours. When these are malignant (harmful), they can develop into liver cancer
Symptoms of liver disease?
Very often, liver diseases do not cause any noticeable symptoms. However, with the development of more severe conditions, the following signs of liver disease can occur.2
- Jaundice: the skin's yellowing and the eye's whites yellowing. It is caused by the liver’s inability to remove bilirubin
- Abdominal pain and swelling on the right side of the body
- Tendency to bruise easily
- Nausea or vomiting
- Changes in the colour of the urine (dark) and stool (pale)
- Chronic fatigue
- Loss of appetite
- Itchy skin
- Swelling in the legs and ankles (edema)
Smoking is one of the main risk factors for liver disease
Smoking has several different effects on the liver, even though it has no direct contact with the smoke. A growing body of evidence shows how smoking plays a role in the progression and severity of the liver disease.3 Studies have also confirmed that smoking further triggers the development of fibrosis and liver cancer.4
Smoking has three main effects on the liver: toxic, immunological, and oncogenic (tumour-causing).4
Tobacco-derived toxins limit liver function
One of the liver’s main roles is to filter toxins from your blood. Smoking has a detrimental effect on this process and stops the liver from effectively removing the toxins from your body.3 Additionally, the chemicals that are the by-product of smoking have a direct negative effect on liver function.3
Thus, smoking has a direct and indirect toxic effect on the liver.5
Direct toxic effects: Due to smoking, chemical substances accumulate in the liver, some of which induce oxidative stress and further trigger the development of fibrosis.
Indirect toxic effects: Heavy smoking decreases the blood’s oxygen-carrying capacity, which results in hypoxia; liver tissue damage due to lack of oxygen. When hypoxia in the liver goes untreated, it can lead to liver failure.
Smoking worsens pre-existing liver problems
There is a need for further studies to determine the precise effects of smoking on liver disease.6 However, there is already evidence that it is associated with the progression and severity of fibrosis and liver cancer.4 Combined with alcohol misuse, smoking makes fatty liver diseases worse.4
Doctors recommend quitting smoking if you have been diagnosed with liver disease.6 Quitting smoking will stop the triggering effects of making liver conditions worse. It also helps the liver to process prescribed medication by not adding more toxins.6
Smoking induces liver inflammation
One of the primary triggers of liver disease is inflammation. Inflammation damages the liver tissue, triggering the development of non-alcoholic fatty liver disease into fibrosis.7 Fibrosis is a condition caused by the excessive accumulation of specific proteins and is involved in most liver diseases.7 Fibrosis can further develop into hepatocellular carcinoma (HCC), the most common type of liver cancer.3,7
Smoking yields chemical substances that contribute to hepatic inflammation and fibrosis in the liver. Smoking also increases the production of pro-inflammatory agents (cytokines) involved in liver cell injury.3
Although smoking causes long-term adverse effects on liver functioning, quitting smoking can reverse them.3 Studies show that immune responses improved within a month of quitting smoking, and the number of pro-inflammatory cytokines decreased.7
Tips on how to quit smoking
Quitting smoking will improve your health considerably. Several sources can help you choose a method that suits you best. You can also visit your doctor, who will be ready to support you.
Some quitting-strategy examples:
- Try nicotine replacement therapy
- Identify your triggers and make a plan to avoid them
- Physical activity helps with the cravings
- Relaxation techniques can help you relieve stress
- Join online support groups
- Remind yourself of the benefits of quitting
- Tell people you are quitting; accountability helps to push through cravings
- Keep busy; it helps keep cravings away
Summary
It is determined from research that smoking harms many of our organs, including the liver. It has a toxic effect on liver function and worsens existing liver conditions.
The chemical toxins from cigarette smoking induce liver fibrosis, which can develop into other conditions such as fatty liver disease and liver cancer.
Studies have also shown that quitting smoking can reverse some of these adverse effects. The doctors highly recommend that those with diagnosed liver conditions quit smoking.
References
- Liver Disease: Types, Causes, Symptoms and Treatment [Internet]. Cleveland Clinic.
- The Liver and Its Functions | Center for Liver Disease & Transplantation | Columbia University Department of Surgery [Internet]. columbiasurgery.org.
- El-Zayadi A-R. Heavy smoking and liver. World Journal of Gastroenterology : WJG [Internet]. 2006 Oct 14;12(38):6098–101.
- Rutledge SM, Asgharpour A. Smoking and Liver Disease. Gastroenterology & hepatology [Internet]. 2020;16(12):617–25.
- Smoking and the Digestive System [Internet]. www.hopkinsmedicine.org.
- Marti-Aguado D, Clemente-Sanchez A, Bataller R. Cigarette Smoking and Liver Diseases. Journal of Hepatology. 2022 Feb;
- Del Campo JA, Gallego P, Grande L. Role of inflammatory response in liver diseases: Therapeutic strategies. World Journal of Hepatology [Internet]. 2018 Jan 27;10(1):1–7.
