In addition to the lungs, smoking can affect the liver, linking to liver disease and liver cancer. However, quitting smoking reduces a person’s risk of developing these conditions.

Cigarette smoking can negatively affect almost every organ in the body — the liver included. It is responsible for more than 480,000 deaths in the United States annually.

According to experts, stopping smoking at any age is better than continuing to smoke. Quitting smoking reduces the risk of liver cancer and liver disease.

This article examines the relationship between smoking and liver health, ways to quit smoking, common questions, and more.

A silhouette of a person smoking, which affects the liver. -1Share on Pinterest
Alpgiray Kelem/Getty Images

As the body’s center for detoxification, the liver is susceptible to cancer, disease, and chronic conditions due to natural toxin exposure.

Cigarette smoking increases the risk of certain liver conditions, like nonalcoholic fatty liver disease (NAFLD) and liver cancer.

A 2020 research review explained smoking’s negative effects appear to link to several separate but intertwined causes:

  • direct and indirect toxicity
  • immunologic mechanisms
  • tumor stimulation

Liver injury from toxicity is one of the primary ways smoking affects the liver.

Toxins from smoking can cause oxidative stress, when cells experience exposure to too many free radicals, which are reactive oxygen particles.

Oxidative stress can lead to liver injury and fibrosis, where tissue thickens and scars.

Over time, fibrosis restricts blood flow and, in its severe form, can become cirrhosis, a condition of permanent damage.

Smoking can also inhibit the immune system’s antibody production. It initiates the loss of lymphocytes, important white blood cells that help clear cancer, infection, and bacteria.

At the same time, certain substances in cigarettes can stimulate tumor growth and suppress the body’s natural anti-tumor genes.

This decrease in function and immunity, paired with smoking’s tumor-promoting features, ultimately makes the liver vulnerable to disease and cancer.

NAFLD is the most common cause of chronic liver disease. It occurs when fat deposits build up inside the liver, causing inflammation and affecting function.

Although medical professionals primarily associate NAFLD with having more weight and insulin resistance, smoking is a known risk factor.

According to a 2022 study, smoking links to NAFLD because nicotine accumulates in the intestine and activates a specific protein called AMPK.

This sets off a chain of events that produce ceramides, lipids that accumulate in the liver and can cause NAFLD progression.

Additionally, smoking may adversely affect females with NAFLD more often than males.

A 2020 population-based cohort study found cigarette smoking linked with a significant increase in all-cause deaths among women with NAFLD. Researchers did not observe an increase in men’s deaths.

NAFLD is not the only type of liver disease smoking affects, however.

A review from 2022 indicated smoking increases the risk of fibrosis progression across many liver diseases with varied causes, such as primary biliary cholangitis and chronic hepatitis infection.

Smoking increases the risk of liver cancer, even among people who quit smoking.

The most common type of liver cancer is hepatocellular carcinoma. A 2021 review pointed out that approximately 4,000 chemicals in cigarettes can adversely affect the body.

Tar, vinyl chloride, nitrosamines, and 4-aminobiphenyl, for example, are chemicals in cigarette smoke that link with hepatocellular carcinoma.

The authors noted the exact mechanisms underlying liver cancer from smoking are complex, but they linked tobacco use with an elevated risk of liver cancer.

The National Cancer Institute states the risk of liver cancer increases with the number of cigarettes smoked in a day and the amount of time someone has been smoking.

As relatively new products arise on the market, research into the effects of e-cigarettes on liver health is limited.

According to the American Cancer Society (ACS), e-cigarettes may contain substances called volatile organic compounds (VOCs). VOCs are capable of damaging the liver at certain levels.

Additionally, a 2022 study noted that out of more than 178,000 respondents, those with liver disease had a higher chance of using e-cigarettes.

Experts consider smoking cessation at any age better than smoking. It reduces liver cancer risk and improves the risk of liver disease.

It is possible to quit smoking “cold turkey,” which means without a gradual decrease in nicotine exposure. Many people require help, however, and find support through:

Self-care strategies, like the following, can assist formal programs:

  • writing an organized “quit plan”
  • staying busy with hobbies, recreation, and wellness activities
  • avoiding events, places, and people that may trigger the urge to smoke
  • cultivating stress management practices
  • getting support for depression and other mental health conditions

Below are some common questions about smoking and liver health.

What does smoking do to the liver?

Smoking affects the liver directly and indirectly through toxin exposure.

It promotes fibrosis, fat accumulation, immunity suppression, and tumor growth.

Can I smoke if I have fatty liver disease?

Smoking can make non-alcoholic fatty liver disease worse. Experts do not recommend smoking with this diagnosis.

Does smoking cause liver enzymes to go up?

Smoking can cause an increase in liver enzymes.

Liver enzymes are markers of liver health. When levels are high, it can be a sign of smoking-related loss of liver function.

Cigarette smoking can increase the risk of liver disease and liver cancer.

Cigarettes expose the body to toxins, and nicotine may boost the production of lipids that contribute to NAFLD.

Smoking cessation can help improve liver cancer and disease risk.