Non-alcoholic fatty liver disease, or simply NAFLD, describes a condition where excess fat accumulates in the liver of people who consume little or no alcohol at all. Although some amount of fat may accumulate in the liver of a normal individual, having fat that takes up to five to ten percent of your liver weight can cause fatty liver disease, which may lead to serious health problems.
What is Non-Alcoholic Fatty Liver Disease ?
The liver is a large, complex organ with many vital functions. One of these is the synthesis, transport, and metabolism of fat, which is an important source of energy. Fat may accumulate in large amounts in the liver when an abnormality in these functions occur, such that there is increased synthesis and/ or reduced transport and metabolism of fat. It is normal to have some fat in the liver, as with other organs in the body, but when more than 5% of the liver’s weight consists of fat, a condition called fatty liver disease develops.
Fatty liver disease is generally categorized into alcoholic and non-alcoholic fatty liver disease, depending on the cause. Non-alcoholic fatty liver disease (NAFLD) is further classified into isolated fatty liver (IFL), in which there is no inflammation involved, and nonalcoholic steatohepatitis (NASH), in which inflammation is involved, often leading to liver damage and serious complications.
NAFLD affects 30 percent of the US adult population and is now the leading cause of chronic liver disease in the country. NASH can progress to serious liver damage, causing cirrhosis (scarring of the liver) and liver cancer, which can lead to liver failure and death. Aside from these, NAFLD is also associated with serious conditions such as heart disease and stroke.
What Causes Non-Alcoholic Fatty Liver Disease?
The exact cause of NAFLD is not known, but certain risk factors have been strongly associated with the liver’s inability to break down fats, which leads to excessive build-up of fats in the hepatic tissues. These risk factors include:
- hereditary/genetic factors
- being middle-aged
- overweight or obesity
- insulin resistance or prediabetes
- type 2 diabetes
- malnutrition or rapid weight loss
- viral hepatitis
- high blood cholesterol
- high blood levels of triglycerides
- metabolic syndrome
- autoimmune liver disease
- certain medications
- gastric bypass surgery
- vitamin D deficiency
- hypothyroidism (underactive thyroid gland)
- hypopituitarism (underactive pituitary gland)
- overgrowth of harmful bacteria in the intestines
Symptoms of Non-Alcoholic Fatty Liver Disease
Many people who have fatty livers do not manifest any symptoms until the advanced stages of the disease. The most common symptoms include fatigue, weakness, loss of appetite, weight loss, and vague pains in the right upper portion of the abdomen. Liver damage that leads to cirrhosis and its complications may be manifested in various ways. These include:
- Edema due to fluid retention
- Enlargement of the abdomen (ascites) due to fluid retention
- Muscle wasting due to protein loss
- Internal bleeding due to rupture of blood vessels from increased pressure
- Yellowing of the skin and eyes (jaundice)
Late stages of the disease can end in liver failure, coma and death.
Treatment of Non-Alcoholic Fatty Liver Disease
Fatty liver disease is reversible if treated before permanent liver damage and cirrhosis occur. There is no specific treatment for NAFLD but since it is strongly associated with certain risk factors such as obesity and diabetes, treating these underlying conditions can help improve liver function.
Many of the risk factors associated with NAFLD may be improved by simple lifestyle changes, including shifting to a healthy, balanced diet and exercising regularly. Avoiding fatty foods as well as processed and sugary foods help promote weight loss. Studies have shown that a significant weight loss of at least 7% may help reduce liver fat and reverse liver inflammation.
Medications aimed at treating underlying conditions such as orlistat to reduce blood cholesterol and metformin to reduce blood sugar levels may help reduce liver inflammation. These medications, however, must be taken in combination with a healthy lifestyle to promote health.
Alternative treatments to prevent or treat fatty liver disease are the subject of many studies. So far, some evidence suggests that vitamin E supplementation as well as antioxidant intake may help reduce liver inflammation. Some investigators have found a link between vitamin D deficiency and fatty liver disease, suggesting that correcting nutritional deficiencies may help protect the liver. Other studies also show that regular coffee drinking protects the liver from damage due to inflammation.
Weight loss surgery or bariatric surgery, which involves gastrointestinal bypass, has been considered as a possible way to reduce fat accumulation and inflammation, as well as preventing the progression of the disease.
For advanced stages of NAFLD, medical treatment is aimed at managing complications. Liver transplantation may be considered when liver failure occurs. In fact, next to hepatitis C and alcoholic liver disease, NAFLD is one of the most common reasons this procedure is being done in the US. Furthermore, with the increasing incidence of obesity and type 2 diabetes, it is predicted that fatty liver disease may become the leading cause of liver transplants.
Medicine Net. Fatty Liver (Nonalcoholic Fatty Liver Disease [NAFLD] and Nonalcoholic Steatohepatitis [NASH]). http://www.medicinenet.com/fatty_liver/article.htm.
Mayo Clinic. Nonalcoholic Fatty Liver Disease. http://www.mayoclinic.org/diseases-conditions/nonalcoholic-fatty-liver-disease/basics/definition/con-20027761.
WebMD. Fatty Liver Disease. http://www.webmd.com/hepatitis/fatty-liver-disease.