What to Know About Nonalcoholic Fatty Liver Disease (NAFLD) and Its Link to Cancer

Annette M. Goldberg, MBA, MS, RD, LDN, is an outpatient oncology dietitian at Dana Farber Cancer Institute (DFCI) in Boston, Massachusetts. She also gains great satisfaction counseling patients through her private practice, Nourish4. You can follow Annette on Twitter.

The liver is the largest internal organ in your body and is located under your rib cage on the right side. It weighs about 3 pounds and is shaped like a football that is flat on 1 side. The liver performs many jobs in your body, including playing a key role in the digestion of food. It processes what you eat and drink into energy and nutrients and removes harmful substances from your blood. No one can live without a liver.

Several types of cancer can form in the liver. The most common type of liver cancer is called hepatocellular carcinoma (HCC), which accounts for approximately 75% of liver cancers. HCC begins in the main type of liver cells, called hepatocytes. Other types, such as cholangiocarcinoma (also called bile duct cancer) and angiosarcoma, are much less common. Liver cancer has many different causes, including a condition called nonalcoholic fatty liver disease, or NAFLD.

What is NAFLD?

NAFLD is the buildup of extra fat in the liver’s cells that is not caused by alcohol. A healthy liver contains some fat, but when more than 5% to 10% of the liver’s weight is fat, the liver becomes inflamed. This condition can be classified as “fatty liver,” also called steatosis. NAFLD affects many adults and children, and it is one of the most common causes of liver disease in the United States, according to the National Institute of Diabetes and Digestive and Kidney Diseases.

If NAFLD becomes severe, it may progress to a condition called nonalcoholic steatohepatitis, or NASH. NASH may result in liver cancer, as well as fibrosis (scarring of the liver), cirrhosis (permanent scarring and hardening of the liver), or liver failure. Experts estimate that about 1 of every 5 people with NAFLD will develop NASH.

What causes NAFLD?

Living a sedentary lifestyle and following a Western diet, which is composed of high-fat foods and refined carbohydrates like sugar and processed grains, both contribute to the development of NAFLD. In the United States, these lifestyle habits have led to an increase in obesity, diabetes, and metabolic syndrome. Metabolic syndrome is usually defined as having a large waistline (obesity); high blood pressure; high triglycerides, which are a type of fat found in the blood; low levels of high-density lipoprotein (HDL) cholesterol, or “good” cholesterol; and high blood sugar even when not eating. These conditions create an inflammatory environment that causes damage to the liver.

What is the link between NAFLD and liver cancer?

If NAFLD is not reversed, the continued inflammatory environment in and around the liver can eventually lead to liver cancer. NAFLD is one of the main risk factors for developing liver cancer. In the United States, liver cancer is the fifth most common cause of cancer death among men and the seventh most common cause of cancer death among women. The overall liver cancer death rate has doubled from 1980 to 2013 and has since leveled off. Despite the development of new treatments for liver cancer, the 5-year survival rate is still 20%. Worldwide, liver cancer is the third leading cause of cancer death. In 2020, an estimated 905,677 people were diagnosed with liver cancer and an estimated 830,180 people died from the disease.

What are the symptoms of NAFLD and NASH? 

NAFLD and NASH are “silent” diseases that typically have no symptoms. However, if symptoms do occur, they may include fatigue, weakness, weight loss, pain in the abdomen, jaundice or yellowing of the skin, swelling in the legs and abdomen, or mental confusion. Blood tests that will identify NAFLD or NASH in the early stages are not standard. Therefore, if you feel you are at risk, you should speak with your doctor.

NAFLD or NASH may also be diagnosed through imaging tests, like those that check for fat in the liver and evaluate the stiffness of the liver. In some cases, a liver biopsy is required to confirm a diagnosis of NAFLD or NASH and to check the extent of the liver damage.

Are there medications available to treat NAFLD or NASH?

There are no medications that have been approved to treat NAFLD, including NASH. However, researchers are studying medications that may help improve these conditions. If NASH leads to cirrhosis, which develops when liver cells are damaged and replaced by scar tissue, doctors can treat many complications of cirrhosis with medications, minor procedures, and other surgeries. If there is liver failure or liver cancer, a liver transplant may be required. Talk with your doctor if you are concerned about developing NAFLD, and they can discuss the best diagnosis and treatment options for you.

What are ways to prevent or reduce the risk of developing NAFLD?

There are many ways to prevent NAFLD, including:

The author has no relevant relationships to disclose.

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