Non Alcoholic Fatty Liver- Up to 30% of Us Have This Already!
- 2nd Jul 2022
- Read time: 12 minutes
- Dr. Max Gowland
- Article
Introduction
NAFLD is a disease of the liver, which can affect up to 30% of the population and is usually associated with other health issues such as type 2 diabetes, obesity, and metabolic syndrome (see separate blog on this). NAFLD is now endemic amongst most Western populations and is growing every year. We need to do all we can to look after the health of our liver, as it is such a crucial organ which is involved with virtually all our basic metabolic processes throughout our body.
But before we go into the detail of NAFLD, let’s briefly set out the basics of the liver and how it operates and what it does.
Our liver is a truly incredible organ weighing around 1.4 kilograms, situated in the upper right quadrant of the abdominal cavity.
Its main function is to ‘filter’ our blood and rid our body of various toxins and waste products. It also behaves like a central chemical processing factory too and carries out thousands of complex bio-chemical reactions to maintain a healthy metabolism.
The liver is fed with two main blood supplies. The first is the hepatic artery, which feeds the liver with oxygen rich blood, whilst the second supply comes from the hepatic portal vein, which brings important nutrients to the liver from the intestines. The liver uses around 13% of our blood supply at any one time making it a very blood rich organ.
The blood from the liver then leaves through the hepatic vein and is returned to the heart for oxygenation.
Physically, the liver is made up of two main lobes (left and right), which each lobe having eight segments, and in turn, these lobes contain thousands of even smaller parts called lobules.
In essence, the liver processes everything we eat and drink. It pulls toxins from the blood, controls blood sugar levels, manufactures many proteins and hormones too. It also helps to fight off infection.
The liver is an incredibly busy bio-factory, whose metabolism comprises the building up and breaking down of thousands of key nutrients, in addition to many detoxification activities too. However, hepatocytes (liver cells) are also responsible for the production of over 80% of innate immunity proteins, protecting us against many external pathogens.
The liver also stores carbohydrates such as sugars and starches, but as a polymeric biochemical called ‘glycogen’. It also stores fats as lipoproteins (fats wrapped with more soluble protein sheaths) and triglyceride fats too. The liver also makes various plasma proteins together with cholesterol and bile, which is a bitter greenish fat-rich liquid, stored in the attached gallbladder, and is required to help with the digestion and emulsification of fats from the diet.
What is NAFLD (Non-alcoholic Fatty Liver disease)?
The liver, inter alia, is an organ that is prone to fatty deposits within its structure, and this can later give rise to much more serious health issues, leading eventually to cirrhosis of the liver, a life threatening disease, with few successful treatment outcomes.
According to many liver specialists, around a third of the population already have NAFLD!
This illustration is a simplified though clear description of the various stages of fatty liver, starting initially with NAFLD, where many of the hepatocytes (liver cells) are bloated with fat deposits within. Though unhealthy, as liver function will be slightly reduced, this problem is in fact quite reversible to an extent with diet, exercise and perhaps some pharmaceutical treatments.
The next stage if considerably worse and is where the fat deposition is allowed to continue unabated and eventually inflammation is initiated. This is called Non Alcoholic Steato-hepatitis, otherwise known as NASH. NASH is a more advanced form of NAFLD whose inflammation can ultimately lead to irreversible scarring (also called fibrosis) of the liver, called Cirrhosis.
NASH can cause fatigue, pain in the upper abdomen, yellow skin and eyes, loss of appetite, confusion and nausea. This is a stage where serious liver damage has now taken place , though some degree of healing is possible.
In the US, NAFLD is estimated to be present amongst 16-29% of the population, but is much more common in obese people where it is estimated to be present in around 66% of obese patients!
With the more advanced NASH, 5% of the population are still afflicted by this more serious disease but again, this increases to 20% of the obese population, making this a huge and growing epidemic in the US. If NASH is left untreated then the liver will undergo serious and irreversible scarring and then Cirrhosis of the liver can then take hold. This disease is sometimes called end stage liver disease. The liver may still carry-on working, albeit inefficiently and can lead to liver failure which can of course be life threatening.
Cirrhosis if left unchecked, can later lead on to liver carcinoma.
Symptoms of this final stage disease include all the exaggerated symptoms of NASH, plus more serious problems including more severe yellowing of the skin and eyes, combined with vomiting blood, swollen legs and dark tarry looking motions.
How is NALFLD and NASH diagnosed?
There are several techniques available to diagnose liver disease. Most of these are markers that are used to demonstrate inflammation of the liver.
The most available and usually the first set of tests are blood tests where a variety of liver relevant enzyme levels are measured. The two most well know are AST (aspartate amino transferase) and ALT (alanine amino transferase), whose levels can be elevated in the liver when there is damage to the hepatocytes. Both ALT and AST are involved in amino acid metabolism.
According to liver specialists, typical levels of AST and ALT are between 8-48 IU/litre and 7-55 IU/Litre, with elevated levels showing two to three times these levels. However, in some more severe serious cases, can cause these levels to multiply by up to 50 times higher!
Another relevant liver enzyme is known as ALP (alkaline phosphatase), again involved in protein breakdown and levels are elevated when the liver is damaged or under duress.
These levels and more importantly, their ratio (of AST/ALT) can also help to determine whether the damage to the liver is acute (short term) or chronic (longer term), which is necessary to develop a diagnosis and therefore effective treatment. Hepatitis C will also cause AST enzymes to spike.
Bilirubin is another substance that is normally produced when red blood cells break down, as part of our normal blood cell turnover. Bilirubin passes through the liver and is excreted in stools, but elevated levels (jaundice) can indicate liver damage. Another common test is called Prothrombin Time (PT) and this measures how long the blood takes to clot. Increased PT is another way of diagnosing liver damage.
Finally, some medications can raise levels of these various liver enzymes too , such as statins, blood pressure drugs, analgesics, NSAIDs, diabetic medicines and even acid reflux products.
What is clear is that a liver specialist is required to initiate the appropriate tests and also to carry out a detailed analysis of the data, as this area of medicine is highly complex.
Imaging techniques for NAFLD/NASH
A commonly used non-invasive imaging technique is ‘Transient Elastography’ and is based on a sophisticated ultrasound device, which sends out shear waves and measures liver stiffness and liver fat levels. This is a fast and low-cost way of diagnosis.
However, better imaging will include CT and MRI, though CT is less precise than MRI for examining the degree of fatty liver.
Liver biopsy is regarded as the gold standard by some practitioners, though the way in which the sampling is carried out can be prone to variation, so a skilled operator is key to its precision.
Treatments for NASH
NAFLD and even NASH can be reversed to some extend by diet and exercise. How many times have we heard this before, assigned to so many disease states, but with fatty liver, it can highly effective. We know that weight loss is key to success.
Portion control, avoidance of sugar sweetened beverages and HFCS (high fructose corn syrup) containing products, avoidance of energy drinks, adding fibre and cutting caloric intake all play a part in helping the fatty liver lose its fat over time.
Pharmaceuticals used to treat NASH include high strength Vitamin E and Pioglitazone, where data shows significant reduction of liver fat and and increase in subsequent health. Having said this, there are no ‘silver bullets’ for fatty liver or NASH. In fact, there are only three of four drugs in phase 3 clinical trials right now.
Are There Supplements that can help Liver Health
First of all, there is no supplement which will ‘detoxify’ the liver. This over used claim is purely marketing fluff and has no real scientific basis. It is the liver itself( and indeed the kidneys too) which detox the blood and the priority is simply to keep the liver in good health and treat it with the respect it deserves.
However, there are certain supplements which have been proven scientifically to support liver health, so let’s look at these with an evidence-based eye.
a/ Choline
According to a recent paper published in Clinical Nutrition and Metabolic Care, humans need a regular intake of choline in their diet. The RDA (recommended daily intake) for choline is around 550 mgs each day. Choline is a key building block in cell membranes and also in its acetylated form, acetyl choline, for neurotransmitter synthesis.
Data also shows that those with low choline intakes, tend to develop fatty liver and if sustained, ultimately more serious liver damage can occur. The main reason for this is that choline is required to help fat based triglycerides to leave the liver and this is why fat can build up. Rich food sources of choline include egg yolks, beef liver, chicken breast and oily fish.
Groups at higher risk of choline deficiency include pregnant women and also some people who have a genetic difference, causing their choline metabolism to malfunction.
Further to the above scientific paper, the European Food Safety Authority (EFSA) have evaluated a huge amount of submitted data and concluded that choline has proven health benefits, allowing legally approved health claims to be made on supplement packs:
- Choline supports the maintenance of liver function
- Choline contributes to a normal healthy fat metabolism in the body
- Choline contributes to normal metabolism of homocysteine (which is a toxic material that can build up in the blood)
So any liver supplement containing at least 83mg of choline per dose will confer these health benefits, all of which can also be claimed on pack and in ads if relevant.
b/ Milk Thistle (Silybum Marianum)
Milk Thistle has for many years been a front-line plant extract aimed at liver health. The active ingredient in milk thistle is silymarin and is another one of nature’s flavonoid structured, anti-oxidant biochemicals used within the health industry. Its use has been shown to be safe and well tolerated even at quite elevated levels.
The most frequent problems with the liver, including NAFLD, NASH and also Hepatitis is chronic inflammation. Silymarin being a powerful antioxidant , reduces the production of these damaging ‘reactive oxygen species’ which if uncontrolled, can wreak havoc and cause severe inflammatory damage. There is also evidence, from multiple scientific studies, all published in peer reviewed journals, that milk thistle reduces levels of both ALT and AST liver enzymes, as mentioned above, thereby benefiting the health of the liver overall, due to reduced inflammation.
c/ Vitamin E
Vitamin E is a well-known antioxidant which works by protecting cells against what the scientists call ‘oxidative stress’ and logically therefore, could play a role in treating inflamed livers. This vitamin has therefore had a long track record of being tested in patients with NAFLD, specifically those with early scarring (fibrosis),usually though, in combination with milk thistle. However, these treatments have been under medical supervision and are usually short term, due to the very high doses of vitamin E used during the therapy. Most clinicians tend to prefer using vitamin E at lower doses and usually in combination with other therapies.
Another even more powerful anti-oxidant is astaxanthin. However, few proper human trials have taken place to date , despite positive pre-clinical experiments showing reduced inflammation and reduced fibrogenesis (formation of scarring) within the liver.
d/ Vitamin D
Though some studies have shown a link between low vitamin D levels and various stages of NAFLD, the evidence is quite weak in more controlled tests and therefore overall, it looks like Vitamin D does not play a powerful role in the attenuation of NAFLD.
e/ Omega 3 Fats
As with many health areas, omega 3 fatty acids (mostly found in oily fish) have been shown to play a role in the lowering of levels of the liver enzyme AST , thereby suggesting that supplementation could contribute to increased liver health. Omega 3 fats are well recognised as powerful anti-inflammatories and therefore adding extra omega 3 to the diet is a sensible treatment.
f/ Curcumin
This active and natural ingredient found in Turmeric, is a proven anti-inflammatory nutrient. In a number of human trials, large doses of curcumin were shown to reduce NAFLD significantly, as proven by liver ultrasound. However, curcumin is a very expensive nutrient and also one which is poorly absorbed making this treatment cost ineffective overall.
g/ Other
There are many other nutraceuticals that have shown beneficial effects on NAFLD, including Flaxseed, L-Carnitine, Berberine and Anthocyanins. However, proper high calibre RCT’s (randomised, double-blind tests) are needed before any of these can be recommended as treatments or co-treatments for NAFLD.
Also, it is accepted that low intake of certain micronutrients can exacerbate inflammation, as many of these micronutrients do play roles in various anti-inflammatory pathways, which is clearly beneficial to inflammation in the liver caused by excess fat. More specifically zinc and copper are critical.
Vitamin A is also a key nutrient, and we know that patients with NAFLD typically have low levels of Vitamin A circulating in blood serum, which tends to worsen as liver disease progresses. However, excess vitamin A can be toxic, so supplementation with this vitamin is not recommended.
And Finally, Pharmaceutical Treatments
Amongst the medical profession, there is still a lack of consensus regarding the most effective treatments and medications. As NAFLD is associated with both inflammation, type 2 diabetes, and increased adiposity (obesity), then the combination of insulin sensitizers, lipid lowering drugs (eg. statins and PCSK9 inhibitors) and Vitamin E seems to be the first choice armoury of pharmaceuticals.
Having said this, other treatments include pentoxifylline (inhibits TNF alpha inflammation), omega 3 fatty acids, probiotics/prebiotics and some herbal medicines too.
Of course, any doctor will also want their patient to gradually reduce weight by reducing their calorific intake, in combination with daily exercise
In summary, NAFLD is a disease which is endemic in the Western population. Unsurprisingly, It is usually associated with diabetes, metabolic syndrome and obesity, all of which play a role in fat deposition into the liver. If left untreated, NAFLD can lead to more serious NASH, with scarring, then onto liver cirrhosis and possibly even liver carcinoma later on in life.
Though there are some treatments available, a healthy well-balanced diet combined with regular exercise must be part of the regimen to rid oneself of this potentially life-shortening disease.
