Mention liver disease to most people and one word will spring to mind – alcohol. And there is no denying drinking to excess is a major cause of liver-related ill health, which is responsible for an estimated 6,000 deaths a year in England alone.
But there is another, much more insidious and far less obvious liver condition that, experts fear, is fast becoming an epidemic.
Non-alcoholic fatty liver disease – or NAFLD – hardly rolls off the tongue.
It’s not a catchy term, it doesn’t enjoy a high public profile like cancer, heart disease or diabetes, and few people outside medicine have heard of it.
Yet this hidden illness, combined with other causes of liver ailments (such as drinking more than the recommended 14 units a week and infections such as hepatitis), means liver disease is now the biggest killer of adults in their 30s and 40s, according to The British Liver Trust.
When singer George Michael passed away in 2016, the coroner’s report listed fatty liver disease as one of the causes of death – it was arguably the first time many British people would have heard of it.
“We are facing a liver disease epidemic,” says British Liver Trust chief executive officer Pamela Healy.
“Thirty years ago it was very rare for liver units to admit people in their 20s with liver cirrhosis (scarring of the liver) but now it is quite common for people this young to die from the disease.
“The liver is just as vital an organ as the heart but people often fail to appreciate the importance of keeping it healthy. There are also lots of myths surrounding it.
“For example, many people believe you need to be an alcoholic to develop liver disease, whereas one in five of us are drinking at a level that puts our liver at risk.
“Many also fail to realise that being overweight is a major risk factor.”
Experts fear liver disease, although mostly preventable, will overtake heart disease as the biggest cause of premature death in the next few years. But why does carrying a few extra pounds around the middle have such a devastating effect on this vital organ?
After all, it’s one of the body’s most resilient components – capable of regeneration after injury or surgery.
The reason is that a healthy liver should contain little or no fat. Yet poor diet and being overweight – not necessarily obese – means up to one in three people in the UK is now in the early stages of NAFLD.
This means they have small amounts of fat in their liver which may not yet be causing them direct harm but, as those levels rise, will raise the risk of diabetes, high blood pressure and kidney complaints.
This build-up of fat causes no symptoms at first – most people get diagnosed during routine tests for something else.
Left unchecked, it turns into a more serious condition called non-alcohol steatohepatitis, or NASH, where the liver becomes inflamed. It’s thought one in 20 people already have NASH.
Over time, this inflammation causes scar tissue around the liver and blood vessels. Yet sufferers may still have no idea because the liver is still able to function normally.
Often, it’s only when things get to the most serious stage, cirrhosis, that the problems become clear. Years of inflammation makes the liver shrink and become lumpy.
By this stage, the damage is irreversible and the chances of liver failure and liver cancer skyrocket.
It’s because this process can go unnoticed until it’s too late that experts stress it’s vital to make lifestyle changes earlier on in life.
“That 5% who get NASH is expected to increase to 7% by 2030,” says Professor Jonathan Fallowfield, head of liver research at the University of Edinburgh.
“By and large most people don’t know they have fatty liver. These are often people who are thin on the outside and fat on the inside.They tend to carry visceral fat around the abdomen and rarely have any symptoms other than fatigue.”
Prof Fallowfield says although NAFLD is not booze-related, there is a major overlap with liver disease that is caused by alcohol.
In other words, people who have a poor diet and lifestyle are more likely to drink too much as well.
And while nobody dies from NAFLD itself, once it progresses to the more serious stage – NASH – around one in 12 patients die within seven years.
Prof Fallowfield adds: “The best treatment for NAFLD is weight loss.
“You only have to lose about 10% of your body weight to reverse it and possibly even reverse liver fibrosis too, boosting your quality of life.
“It’s a condition that is very reversible. However, we know about 85% of people are unable to lose and maintain even 10% weight loss. They find it too difficult.
“This explains why drug firms are very excited about a possible future role for drugs in treating NAFLD – although there’s nothing available at the moment.”
Pamela Healy says: “It’s vital we alert people of all ages to the risk factors so they can make simple lifestyle changes.”