When I was at medical school 20 years ago, we learnt all about the various causes of liver disease including alcoholic liver disease and hepatitis viruses. We were never taught about Non-alcoholic Fatty Liver Disease simply because it wasn’t very common. Fast forward 20 years and Non-alcoholic Fatty Liver Disease (NAFLD) is now the commonest cause of liver disease in the western world, with some studies estimating that an absolutely astounding 25% of people are now affected by NAFLD¹. So what is NAFLD and why has it exploded to become so widespread?
NAFLD actually constitutes a range of conditions. In some people, there is additional fat in liver but the liver is otherwise functioning normally. However, in up to 20% of people the condition progresses from simply having extra fat in the liver to having inflammation of the liver (hepatitis) or possibly even scarring of the liver (cirrhosis)¹. Even more worryingly, in some cases it can lead to the development of liver cancer. NAFLD is already one of the commonest reasons for liver transplantation and will no doubt become the most common reason for needing a liver transplant².
So what has changed over those 20 years to cause so many people to accumulate extra fat in their liver? The rise in NAFLD mirrors the rise in obesity. Both are driven primarily by the changes in the food environment around us which has resulted in excessive consumption of ultra-processed foods, heavy in added sugar and refined carbohydrates.
The good news is that as this is a disease caused by our diets, it can also be fully reversed by changing our diets. The two most important points are firstly to act early before the extra fat has had the opportunity to cause inflammation or scarring (cirrhosis), and secondly to make the right long term dietary changes.
The bad news is that most GPs and liver specialists who are diagnosing NAFLD know next to nothing about diet and nutrition, and even less about how people effectively change their eating behaviour. Most doctors are only interested in prescribing medication, but with NAFLD there are as yet no medications that have been proven to effectively treat the condition (although drug companies are investing many millions of dollars to be the first to find an effective medication). This means many doctors do not take this condition as seriously as they should, despite the very significant risks. Only last week I spoke to a patient whose previous GP had not even told him that he had NAFLD because the GP did not think it was important!
Those doctors that do try to help often have no training in what the specific dietary advice should be, and NHS patients struggle to access the support from dietitians and health coaches that is required to embed any dietary changes long term. Often people are simply told to go away and lose weight (somehow), or worse still are told to go on a low fat (i.e. higher carbohydrate) diet.
There are a few simple dietary principles when looking to reverse NAFLD but by far the most important is to reduce added sugar, and ideally eliminate it entirely from your diet. Added or “free” sugar is found in sugar sweetened beverages and ultra-processed food. This type of sugar is known as sucrose and it is a combination of two smaller sugars known as glucose and fructose. A small amount of glucose is essential for life and is used by every cell in the body, but when we consume too much glucose the liver turns this into fat. However, by far the most important factor in NAFLD is fructose. Fructose has no purpose in the body and can only be metabolised by the liver. It is even more readily turned into fat by the liver and has a number of other toxic effects on the liver, and is a key driver of NAFLD³. So a simple and essential first step for anyone looking to reverse NAFLD is to avoid sugary drinks, including fruit juices - fructose within fruit itself comes packaged with additional nutrients and vitamins but more importantly comes with multiple forms of fibre that limit how much sugar can be absorbed into the body (and the fibre also feeds our all important gut microbiome).
So why do we not hear much about NAFLD in the media and why is this not being viewed as a crisis? Sadly, this reflects the fact that as yet there are no proven drug treatments. Rest assured, many are in development, and once that lucky pharmaceutical company has licensed the first medication, suddenly everyone will be hearing a lot more about the scale of the problem and the risks of not treating it (just look at how the advent of “skinny jab” Wegovy has suddenly made people notice that there is an obesity crisis!).
Of course, by the time policy makers and the medical establishment start to take this seriously it will be too late for many – much avoidable suffering and death will have already occurred. In the meantime, I am here for anyone who wants to have a conversation about reversing fatty liver disease before it causes serious problems.
Dr Neel Gupta May 2023
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