Surreal illustration of liver entwined with cigarette and alcohol.

Alcohol, Smoking, and Your Liver: What You Need to Know

"Uncover the synergistic dangers of alcohol and smoking on liver health, and practical steps you can take to protect yourself."


If you're a gastroenterologist, you're likely to encounter patients with alcoholic liver disease (ALD). The spectrum of this disease is wide ranging; patients may have mild elevations in liver transaminases, or end-stage cirrhosis and hepatocellular carcinoma. Proper patient care is critical to increase survival. This review covers aspects of ALD, including alcoholic hepatitis and hepatocellular carcinoma.

Alcohol consumption is widespread. A large percentage of US citizens report lifetime consumption of alcohol, with a significant amount of pure alcohol consumed yearly. Unfortunately, this leads to many deaths annually in the US. Alcoholic liver disease (ALD), resulting from alcohol consumption, is a major cause of cirrhosis.

Alcohol is primarily metabolized into acetaldehyde. While the CYP2E1 system typically handles a small part of this process, it can be induced by its substrates and greatly upregulated in those who consume large amounts of alcohol. CYP2E1 induction leads to increased production of reactive oxygen species and DNA damage, increasing the risk of cancer. Acetaldehyde, an intermediate product of ethanol metabolism, is highly reactive and carcinogenic, contributing significantly to alcoholic liver disease. Since the enzymes involved are highly expressed in hepatocytes, the most harmful effects of ethanol are seen in the liver.

Understanding the Risks: How Alcohol and Smoking Impact Your Liver

Surreal illustration of liver entwined with cigarette and alcohol.

Alcohol is an established risk factor for cirrhosis. Current recommendations usually set a "safe" limit for alcohol consumption at around 30 g per day for men and 20 g per day for women. However, evidence suggests these cut-offs may be too high. Inter-individual differences in hepatic sensitivity to alcohol likely play a role in the risk of developing cirrhosis.

Several factors modify the risk of developing ALD. While 90% of people who consume more than 60g of alcohol per day develop steatosis, only up to 30% develop significant fibrosis or cirrhosis. A low to moderate alcohol consumption is considered safe in most countries, but a more restrictive approach is advised in some countries. Meta-analyses suggest that the risk for cirrhosis is present for those consuming more than 25 g of alcohol per day, and increased liver-related mortality can be found in persons consuming between 12 and 24 g of alcohol per day.

  • Binge-drinking: Consuming more than five units of alcohol at the same occasion for men and four for women is linked to a higher risk of ALD and mortality.
  • Drinking outside of meals: Drinking outside of meals increases risk for ALD compared to drinking only at mealtimes.
  • Genetics: Gender and genetic factors also play a role. Women are at higher risk for developing ALD, and genetic mutations in the PNPLA3, TM6SF2, and MBOAT7 genes are strongly associated with ALD and alcoholic cirrhosis.
Smoking also appears to increase the risk for liver disease. A study of patients with hepatitis C found smoking to be an independent risk factor for higher fibrosis stage. A meta-analysis found an increased relative risk for HCC for current smokers compared to non-smokers, indicating that smoking significantly compounds the risk of liver damage.

Protecting Your Liver: Key Steps for a Healthier Future

The first and most crucial step in protecting your liver is reducing or eliminating alcohol consumption. Abstinence has been shown to improve prognosis, even in end-stage liver disease. Assisting patients in achieving abstinence is paramount, and requires a multi-disciplinary approach involving gastroenterologists, addiction specialists, and other healthcare professionals.

Quitting smoking is another vital step. Smoking compounds the risk of liver damage and HCC. Patients with chronic liver diseases should be informed of the increased risk, and offered appropriate counseling and/or therapies to help them quit.

Understanding your individual risk factors is also key. Regular check-ups and screenings, especially for those with cirrhosis, can help detect liver cancer early, when curative therapies are still an option. By taking these steps, you can significantly reduce your risk and improve your long-term liver health.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1016/j.bpg.2017.09.003, Alternate LINK

Title: Alcohol, Smoking And The Liver Disease Patient

Subject: Gastroenterology

Journal: Best Practice & Research Clinical Gastroenterology

Publisher: Elsevier BV

Authors: Hannes Hagström

Published: 2017-10-01

Everything You Need To Know

1

How does alcohol consumption affect the liver?

Alcohol consumption is a major risk factor for liver disease. This means that the more alcohol you drink, the higher your chance of developing conditions like cirrhosis. The body metabolizes alcohol, which leads to the production of acetaldehyde, a harmful substance that can damage liver cells, potentially leading to alcoholic liver disease (ALD). The effects of alcohol on the liver can vary, but it can result in conditions ranging from mild elevations in liver transaminases to end-stage cirrhosis and hepatocellular carcinoma.

2

Does smoking have any impact on liver health?

The impact of smoking on the liver is significant because it increases the risk of liver disease. Studies have shown that smoking is an independent risk factor for higher fibrosis stage in individuals with hepatitis C. Furthermore, it elevates the relative risk of hepatocellular carcinoma (HCC) for current smokers, indicating that smoking compounds the risk of liver damage. This means that if you smoke, you are more likely to develop serious liver problems.

3

How is alcohol processed in the liver, and what are the implications?

The liver processes alcohol. The liver metabolizes alcohol, primarily breaking it down into acetaldehyde, a highly reactive and carcinogenic intermediate. The CYP2E1 system, induced by high alcohol intake, further contributes to liver damage by producing reactive oxygen species and DNA damage. This process is primarily carried out by hepatocytes, which are liver cells. The damage to these cells increases the likelihood of developing ALD, and ultimately cirrhosis.

4

What is considered a 'safe' amount of alcohol consumption?

The 'safe' amount of alcohol consumption is a subject of debate. While recommendations often suggest limits, such as 30 g per day for men and 20 g per day for women, it's important to note that these cut-offs may be too high. Individual sensitivity to alcohol varies. Moreover, there are several risk factors. These include binge-drinking (consuming more than five units for men and four for women), drinking outside of meals, and genetic factors, such as specific mutations in the PNPLA3, TM6SF2, and MBOAT7 genes. These factors influence the development of conditions like ALD and cirrhosis. Therefore, 'safe' limits can vary from person to person.

5

What steps can be taken to protect the liver from damage?

Protecting the liver involves several key steps. The most crucial step is to reduce or eliminate alcohol consumption. Abstinence from alcohol has been shown to improve the prognosis, even in end-stage liver disease. It's critical to seek help from healthcare professionals, including gastroenterologists and addiction specialists, to achieve this. Additionally, avoiding smoking and adopting a healthy lifestyle can further safeguard liver health. The aim is to minimize exposure to harmful substances like alcohol and nicotine to prevent liver damage and related diseases such as ALD and HCC.

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