What is nonalcoholic fatty liver disease (NAFLD)?
Nonalcoholic fatty liver disease (NAFLD) is a condition in which excess fat accumulates in the liver of people who drink little or no alcohol. It is a common condition that affects up to 25% of adults in the United States and is closely associated with obesity and type 2 diabetes.
Which are the 4 stages of nonalcoholic fatty liver disease (NAFLD)?
Non-alcoholic fatty liver disease (NAFLD) progresses through 4 main stages. Most people will only ever develop the first stage, which is a largely harmless build-up of fat in the liver cells known as simple fatty liver or steatosis. However, in a small number of cases, NAFLD can progress and eventually lead to liver damage if not detected and managed.
The more serious form of NAFLD is non-alcoholic steatohepatitis (NASH), where the liver becomes inflamed. Persistent inflammation can cause scar tissue to form around the liver and nearby blood vessels, leading to fibrosis. At this stage, the liver can still function normally.
However, if left untreated, NAFLD can progress to cirrhosis, the most severe stage, where the liver shrinks, becomes scarred and lumpy, and is permanently damaged. Cirrhosis can cause liver failure (where the liver stops working properly) and liver cancer (hepatocellular carcinoma). It can take years for fibrosis or cirrhosis to develop, so it is important to make lifestyle changes to prevent the condition from getting worse.
What is the exact cause of nonalcoholic fatty liver disease (NAFLD)?
The exact cause of NAFLD is not well understood, but it is believed to be related to metabolic syndrome, insulin resistance, and oxidative stress. A new classification based on the pathophysiology of fatty liver disease (FLD) has recently been proposed, as shown in the Figure below.
Who is at risk to develop nonalcoholic fatty liver disease (NAFLD)?
Non-alcoholic fatty liver disease (NAFLD) is a condition that can affect anyone, but certain factors increase your risk. If you are obese or overweight, especially with excess fat around your waist (an “apple-like” body shape), have type 2 diabetes, insulin resistance, polycystic ovary syndrome, an underactive thyroid, high blood pressure, high cholesterol, metabolic syndrome (a combination of diabetes, high blood pressure, and obesity), over the age of 50 or smoke, you are at an increased risk of developing NAFLD.
However, NAFLD can also be diagnosed in individuals without any of these risk factors, including young children. It is important to note that unlike alcoholic liver disease (ALD), NAFLD is not caused by excessive alcohol consumption.
What are the main symptoms of nonalcoholic fatty liver disease (NAFLD)?
In the early stages of NAFLD, there are usually no symptoms, and individuals may not realize they have the condition until it is detected during tests performed for another reason. However, in some cases, people with NASH or fibrosis (more advanced stages of NAFLD) may experience dull or aching pain in the upper right abdomen (over the lower right side of the ribs), extreme tiredness, unexplained weight loss, and weakness. As cirrhosis (the most advanced stage) develops, more severe symptoms can occur, such as jaundice (yellowing of the skin and whites of the eyes), itchy skin, and swelling in the legs, ankles, feet, or abdomen (edema).
Is nonalcoholic fatty liver disease (NAFLD) diagnosed through specific tests?
To diagnose nonalcoholic fatty liver disease (NAFLD), doctors usually start with a liver function test to check for abnormal liver enzyme levels. However, NAFLD can be asymptomatic, so additional tests may be necessary to confirm the diagnosis.
An ultrasound scan of the abdomen may reveal a build-up of fat in the liver, and can be used to diagnose simple fatty liver (steatosis). If further evaluation is needed, a FibroScan or a specialized blood test may be ordered to determine the stage of the disease.
A biopsy may also be recommended to confirm the diagnosis and assess the degree of liver damage. During this procedure, a small sample of liver tissue is taken using a needle and sent to a laboratory for analysis. Other imaging tests, such as a CT scan or MRI, may also be used to assess liver health and diagnose any potential complications.
What 10 tips would Dr. Zavos, board-certified gastroenterologist in Thessaloniki Greece, recommend to the patients with nonalcoholic fatty liver disease (NAFLD)?
Many people with fatty liver disease reach out to me for advice on treatment. If you’re looking to modify or reverse the condition, here are ten helpful tips:
- Incorporate exercise into your routine. Studies have shown that aerobic exercise, resistance training, and high-intensity interval training all have benefits on fatty liver.
- Watch your calorie intake. Low calorie dietary interventions have been found to be the most effective. Aim for a daily intake of 1000 to 1500 calories with a deficit of 500-750 calories. Additionally, the Mediterranean diet without alcohol has shown to be helpful.
- Get enough sleep. Poor sleep, inadequate sleep (less than 6 hours), non-restorative sleep, and daytime napping for more than 60 minutes are all associated with new onset or worsening of fatty liver. Ensure that you prioritize getting enough quality sleep.
- Consider drinking coffee. While tea lovers might not appreciate it, studies have shown that coffee intake can reduce fatty liver disease. Ideally, consume black coffee without sugar or milk, at least three cups a day, and avoid drinking it late in the evening or at night. This dose of coffee is safe and may even lower blood pressure.
- Limit or eliminate alcohol consumption. Alcohol use is a leading cause of fatty liver, so the safest level of alcohol consumption to prevent fatty liver is zero. Switch to non-alcoholic beverages with low calories instead. NAFLD may not be caused by alcohol, but drinking alcohol may deteriorate NAFLD.
- Avoid sugar-sweetened beverages and processed foods that contain fructose. These items can significantly increase liver fat and have been linked to fatty liver in both children and adults.
- Use artificial sweeteners with caution. Although artificial sweeteners are generally safer than natural sugars, studies have shown that they may increase liver fat in animal models due to their effects on gut bacteria. Stevia is considered the safest artificial sweetener. If you have diabetes or obesity, talk to your healthcare provider before using artificial sweeteners.
- Be cautious with drug therapy. There are currently no FDA-approved drugs for treating fatty liver disease, but vitamin E and pioglitazone are recommended by some experts. No other drugs have been shown to be effective. Drug therapy should only be initiated in individuals with confirmed nonalcoholic steatohepatitis (NASH) ideally through biopsy or noninvasive tests like Fibroscan/Shearwave. It is important not to initiate treatment based solely on an ultrasound scan identifying fatty liver. Drug therapy is typically not used for a lifetime but rather until other associated risk factors are under control.
- Take a rational approach to treating fatty liver. Fatty liver disease is actually a misnomer; it is not a disease but rather an association with underlying causes such as alcohol use, diabetes, obesity, hypothyroidism, sleep disorders, and a sedentary lifestyle. Therefore, treatments should focus on controlling these underlying causes instead of the liver itself. For more information on management and updates, refer to the 2022 American Association of Clinical Endocrinology (AACE) guidelines for nonalcoholic fatty liver disease.
- Be aware of what does not work. Ursodeoxycholic acid, milk thistle, green tea, omega-3 supplements, detox products, yoga (because it is not aerobic), fruitarian diets, crash diets, turmeric/cinnamon supplements, shifting to honey or coconut sugars, herbal formulations, multiherbal products, and any product labeled as a “liver detox” or “reverse fatty liver” are not effective treatments for fatty liver disease. For example, omega-3 fatty acids have been shown to reduce the amount of fat stored in liver cells, which can help improve liver health in individuals with non-alcoholic fatty liver disease (NAFLD). However, while omega-3 supplements may have a modest effect on reducing liver cell inflammation, they do not have any significant impact on liver fibrosis, which is a more serious stage of the disease. Therefore, omega-3 supplements are not typically recommended as a specific treatment for non-alcoholic steatohepatitis (NASH) or advanced stages of NAFLD.
How can I contact gastroenterologist Dr. Zavos for an appointment?
Dr. Chris Zavos is a board-certified gastroenterologist and hepatologist, located in Thessaloniki Greece, and specifically in Kalamaria suburb, about 7 kilometres (4 miles) southeast of downtown Thessaloniki. His private office is at: Fanariou 8 street (near Aigaiou and Adrianoupoleos avenues), Kalamaria (Thessaloniki), Greece.
Thessaloniki International Airport is only 10 km away from his private office in Kalamaria and can be reached by taxi within 13 minutes from the airport.
Dr. Chris Zavos performs endoscopies at Bioclinic private hospital in downtown Thessaloniki (Mitropoleos 86 street).
You can contact Dr. Zavos at phone numbers: (+30)-6976596988 and (+30)-2311283833, or you can email him at firstname.lastname@example.org. Dr. Zavos responds to Greek and English languages.
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