According to Greek mythology, Zeus punished Prometheus for giving fire to humans. He chained Prometheus up and set an eagle to feast on his liver. Each night, the liver grew back and each day, the eagle returned for his feast. In reality, can a liver really grow back?
The liver is the largest internal organ in the human body. It is needed for hundreds of bodily processes, including breaking down toxins such as alcohol. As it is the first organ to "see" alcohol that has been drunk, it is not surprising that it is the most susceptible to alcohol's effects. However, other organs, including the brain and heart, can also be damaged by long-term heavy alcohol use.
As a liver specialist, I meet people with alcohol-related liver disease every day. It is a spectrum of disease ranging from laying down of fat in the liver (fatty liver) to scar formation (cirrhosis) and it usually doesn't cause any symptoms until the very late stages of damage.
At first, alcohol makes the liver fatty. This fat causes the liver to become inflamed. In response, it tries to heal itself, producing scar tissue. If this carries on unchecked, the whole liver can become a mesh of scars with small islands of "good" liver in between - cirrhosis.
In the late stages of cirrhosis, when the liver fails, people can turn yellow (jaundice), swell with fluid and become sleepy and confused. This is serious and can be fatal.
Most people who regularly drink more than the recommended limit of 14 units of alcohol per week (about six pints of normal strength beer [4% ABV] or about six average [175ml] glasses of wine [14% ABV]) will have a fatty liver. Long-term and heavy alcohol use increases the risk of developing scarring and cirrhosis.
Good news
Fortunately, there is good news. In people with fatty liver, after only two to three weeks of giving up alcohol, the liver can heal and looks and functions as good as new.
In people with liver inflammation or mild scarring, even within seven days of giving up alcohol, there are noticeable reductions in liver fat, inflammation and scarring. Stopping alcohol use for several months lets the liver heal and return to normal.
In heavy drinkers with more severe scarring or liver failure, giving up alcohol for several years reduces their chance of worsening liver failure and death. However, people who drink heavily can be physically dependent on alcohol and stopping suddenly can cause alcohol withdrawal.
In its mild form, it causes shaking and sweating. But if severe, it can cause hallucinations, fits and even death. Going "cold turkey" is never recommended for heavy drinkers, who should seek medical advice about how to safely give up alcohol.
Other benefits
Giving up drinking also has positive effects on sleep, brain function and blood pressure.
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Avoiding alcohol for long periods also reduces the risk of several types of cancer (including liver, pancreas and colon) and the risk of heart disease and stroke.
However, alcohol is not the only cause of ill health. Giving it up has many health benefits, but it is not a panacea. It should be seen as part of a healthy lifestyle, including a balanced diet and regular physical exercise.
So, to answer the question posed by the myth of Prometheus, the liver has an amazing power to repair itself after it has been damaged. But it cannot grow back as new if it was already severely scarred.
If you stop drinking and only have a fatty liver, it can quickly turn back to normal. If you had a scarred liver (cirrhosis) to start with, stopping alcohol will allow some healing and improved function but can't undo all the damage that has already been done.
If you want to look after your liver, drink in moderation and have two to three alcohol-free days each week. That way, you won't have to rely on the liver's magical self-healing power to stay healthy.
Ashwin Dhanda, Associate Professor of Hepatology, University of Plymouth
