Understanding fatty liver disease: risks, progression and treatment

Liver disease is a growing problem in the UK with deaths increasing 400% since 1970, in stark contrast to other chronic (long-term) diseases, such as heart disease and diabetes, where deaths have decreased over the years. This makes liver disease the third commonest cause of premature death in the UK and the leading cause of death in 35–49 year olds. 

Two of the major contributors to this rising death toll are obesity and drinking too much alcohol, both of which can damage your liver, causing fatty liver disease. Before we delve into fatty liver disease, it helps to understand a little about your liver. 

A healthy liver

Your liver performs a variety of functions to keep your body healthy. This includes filtering out toxins and harmful bacteria, producing bile to help digest your food, producing proteins that help your blood clot, and storing iron to prevent the damaging effects of excess iron in your body. Damage to your liver can, therefore, have a significant effect on your health.

Liver disease: causes and risk factors

The two commonest causes of liver disease are alcohol-related liver disease and non-alcoholic fatty liver disease (NAFLD). 

As the name suggests, alcohol-related liver disease is caused by drinking too much alcohol, which leads to scarring (fibrosis) of your liver. It is recommended that men and women shouldn’t drink more than 14 units of alcohol per week. A pint of lager is three units, a bottle of wine around 10 units and a large glass (250ml) of wine is three units.  

It is recommended that heavy drinkers ie woman who drink more than 35 units of alcohol per week and men who drink more than 50 units of alcohol a week, should have a liver Fibroscan® to detect early signs of liver cirrhosis.  

NAFLD is not related to drinking excessive amounts of alcohol, although if you have the condition, drinking alcohol can make it worse. Much like alcohol-related liver disease, NAFLD also starts with excessive fat developing in the liver. The main risk factors for developing NAFLD are metabolic: obesity, diabetes, high blood pressure and high cholesterol. 

How NAFLD progresses

NAFLD refers to a spectrum of disease. In its mildest form, it is called simple fatty liver, where you have elevated levels of fat in your liver but this hasn’t yet damaged your liver. As a result, you have no symptoms, however, you are nonetheless at greater risk of developing other serious health conditions, including diabetes, heart disease and kidney disease. 

Most people with NAFLD have simple fatty liver but around a fifth may go on to develop non-alcoholic steatohepatitis (NASH). NASH occurs when your liver becomes inflamed and your liver cells are damaged. This puts you at greater risk of permanently scarring your liver, resulting in fibrosis and later liver cirrhosis. This also increases your risk of liver failure and liver cancer. 

Getting a diagnosis of NAFLD

If you’re concerned that you’re at risk of NAFLD eg if you are diabetic, obese or have had an ultrasound scan for an unrelated condition that revealed abnormalities in your liver, it is important to see a specialist or your GP for assessment. 

NAFLD is traditionally tested for with a blood test called a liver function test. This test detects levels of specific liver enzymes, which will indicate to your GP whether your liver is healthy or not. More recently, a tool called FibroScan® has revolutionised the management of NAFLD. 

FibroScan® uses ultrasound waves to measure the stiffness of your liver tissue and estimate how much, if any, fibrosis, scarring and fatty build-up has occurred. It can, therefore, detect liver cirrhosis in its earliest stages, so treatment can be given before any symptoms appear. This reduces the risk of the condition progressing. 

Why testing and early detection are important

Early detection of NAFLD is vital to prevent liver cirrhosis, liver failure and liver cancer. In around 90% of cases, cirrhosis can be successfully prevented from progressing with lifestyle changes. The challenge is getting a diagnosis when in most cases, NAFLD is symptomless until it has progressed to a more advanced stage. This is why it is important to see your GP if you meet any of the risk factors we’ve already discussed.

Treating NAFLD

The main treatment for NAFLD involves lifestyle changes. In those who are overweight or obese, just 5–10% weight loss has been shown to reduce liver inflammation and scarring. It is important that people with NAFLD are thoroughly assessed to estimate their risk of developing cirrhosis and monitored long term.

In addition, if you have diabetes or high blood pressure, it is important to make sure they are well controlled. You should also avoid drinking too much alcohol, keeping to less than 14 units a week — this is roughly equivalent to one bottle of wine or four pints of beer. 

Although there are some promising drug treatments in development, these are not a substitute for lifestyle changes and are designed to support changes in diet and behaviour.