Your amazing liver
How often do you think about your liver? As with most hidden parts of our body, we often don’t think about it much until something goes wrong with it. Yet your liver is truly remarkable. Here are some facts about this amazing organ:
- It is the heaviest organ in the body
- The only organ larger is the skin
- The liver uses 27% of the energy of the body at rest
- It filters 1.4 litres of blood every minute
- All nutrients that are absorbed in the digestive system are first transported in the blood to the liver, so that any toxins can be filtered out before the blood gets into general circulation
The liver is a very busy organ indeed – it is estimated that it carries out over 500 functions! Some of these include:
- Cleansing the blood of microbes
- Metabolising and detoxifying drugs, toxins and alcohol
- Metabolising and detoxifying used hormones
- Producing bile, which is needed to emulsify dietary fats
- Regulating blood glucose levels and storing glucose as glycogen,
- Making cholesterol, which gets used to make vitamin D, sex hormones and adrenal hormones
- Metabolism of protein (amino acids)
- Heating the body
- Storage of vitamins A, D, E, K, B12, iron and copper
- Making plasma proteins, such as proteins which transport other molecules through the blood
- Making vitamin A from beta-carotene
- Activating vitamin D
- Breaking down old red blood cells
Phew! I don’t know about you, but I feel tired just reading that! Can you imagine all that going on in your liver as you are reading this?
Why might you need to help your liver?
The liver is certainly busy, and remarkably good at carrying out its multiple roles. However, modern-day living places many stresses on the liver that it did not evolve to deal with, such as:
- Alcohol intake
- Environmental toxins (heavy metals, pesticides, plastics in food packaging)
- Prescription drugs/over the counter medicines
- Allergies/food intolerances
- Poor eating habits
- Coffee and energy drinks
- Infection or illness
Signs of an overburdened liver include allergies and chemical sensitivities, skin conditions or itching, brain fog/lethargy, anxiety and depression, difficulty digesting fats, hormonal imbalances and chronic fatigue. In some people, issues with cholesterol metabolism and gallbladder health may also be linked to a liver that is under stress. And of course there is the growing issue of fatty liver disease, which can increase the risk of both type 2 diabetes and cardiovascular disease.
Even if your liver is in good health, it makes sense to take steps to try to keep it healthy. One of the principles of functional medicine is to promote what is called “organ reserve” as a means of preventing disease and ensuring optimal health. This recognises that we need our vital organs, such as the lungs, heart and liver, to have a degree of capacity to cope with unexpected events. If our liver fails, we’re in trouble, so it makes sense to give it a little TLC.
First steps to take the pressure off your liver
There are some obvious things you can do to reduce the work that your liver has to do so that it can be more effective. Reducing or stopping drinking alcohol is the first thing many people will think of, and it is an important one. Alcohol is a toxin that requires effort on the part of the liver to detoxify it. Avoiding toxin exposure as much as possible by stopping smoking, buying organic food whenever possible, using natural cleaning products and organic toiletries and cosmetics can also greatly reduce the amount of detoxification that the liver has to do. If you take multiple prescription drugs, it may be worth having a medications review with your GP or pharmacist to ensure that you are not taking more drugs than you need to and putting extra pressure on your liver. (Have a look at my blog post Detox: Fad or Necessity? to read more about detoxification.)
We also need to consider non-alcoholic fatty liver disease (NAFLD), which is increasing in prevalence. An accumulation of fat in the liver prevents it from doing its job properly; in fact, Professor Roy Taylor of Newcastle University has demonstrated that when type 2 diabetics are placed on a low calorie diet such that they reduce the amount of fat within the liver, they can reduce their type 2 diabetes!(1) This is because an excess of fat cells in the liver causes insulin resistance, a situation in which the body is unable to respond properly to the hormone insulin, causing blood sugar levels to rise.
Risk factors for NAFLD include having a body mass index (BMI) in the range classed as obese, and having a wide waist circumference (102cm or above in men, 88cm or above in women)(2). Initial studies suggest that a reduced carbohydrate diet may also be helpful in reducing accumulations of liver fat(3). Consumption of excessive amounts of fructose leads to fat accumulations in the liver, as fructose is taken up rapidly by the liver after consumption, where it causes hepatic inflammation and cellular stress(4). “Excessive amounts” does not refer so much to the fructose we obtain from eating fruit, but from soft drinks and glucose-fructose syrups. So maintaining a healthy body weight, reducing the amount of carbohydrate in the diet whilst increasing healthy fats, and reducing sugary drinks and snacks are important steps to take to address NAFLD.
Why having enough stomach acid is important
Stomach acid stimulates the pancreas to produce digestive enzymes and the liver to produce bile. If stomach acid is low (as is often the case as we age), bile flow can be reduced. This can result in difficulties digesting fats and bile which is not flowing freely can also increase the risk of gallstones.
Stomach acid is also depressed by medications such as antacids and proton pump inhibitors. These are really intended for short–term use only, so if you have been taking them for a long time then it may be a good idea to review their use with your doctor. Stomach acid can be stimulated by drinking 1 tablespoon of apple cider vinegar in a small glass of water 10 minutes before each meal.
Food to support the liver
Before we consider which foods can contribute to liver health, we should consider water. Water is needed to maintain the water content of bile. Staying hydrated also supports the kidneys so that they can help the liver in its detoxification role.
Cruciferous vegetables are my favourite foods for supporting the liver. The cruciferous family includes broccoli, Brussels sprouts, cabbage, cauliflower, horseradish, kale, kohlrabi, pak choi, radish, rocket, turnip and watercress, so there are plenty to choose from. These superfoods modulate and upregulate detoxification enzymes in the liver, encouraging the detoxification of carcinogens and excess hormones(5). Their characteristic bitter flavour stimulates the liver generally (more on that below).
Turmeric is a yellow coloured spice traditionally used in Indian cooking. Among its many benefits, it is said to protect the liver from damage, encourage the regeneration of liver cells and increase bile flow.
Garlic, onions, leeks, spring onions, cruciferous vegetables and eggs are rich in sulphur, which the liver joins to toxins to remove them from the body.
For centuries, bitters have been used as a digestive aid and as a support for the liver. Bitter leaves include rocket, kale, dandelion leaves, radicchio and endive. They promote good digestion by stimulating digestive enzymes and bile flow. They also upregulate liver detoxification. Interestingly, they do this because they contain small amounts of toxins (this is why humans instinctively avoid bitter tastes, as they denote poison). As a result of the toxins, the liver works harder to detoxify, and the overall result is increased function.
Other foods which stimulate bile flow (important for preventing the formation of gallstones) include olive oil, dandelion root, globe artichokes, turmeric, celery, radish, garlic, asparagus and beets.
Finally, the liver requires enough protein in order to detoxify. Always choose the highest quality protein you can, particularly when it comes to animal protein.
So, if you want to say “thank you” to your liver for all the work it does keeping you healthy, why not give it a helping hand?
- Lim, E.L., Hollingsworth, K.G., Aribisala, B.S. et al. (2011). ‘Reversal of type 2 diabetes: normalisation of beta cell function in association with decreased pancreas and liver triacylglycerol’, Diabetolgia, 54(10), pp2506-2514. [Online]. Available at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3168743/ (Accessed 28 May 2018).
- National Guideline Centre (UK) (2016). ‘Non-Alcoholic Fatty Liver Disease: Assessment and Management’, National Institute for Health and Care Excellence, NICE Guideline no. 49, 5. Risk factors for NAFLD. Available at https://www.ncbi.nlm.nih.gov/books/NBK384735/ (Accessed 25 May 2018).
- Mardinoglu, A., Wu, H., Bjornson, E. et al. (2018). ‘An Integrated Understanding of the Rapid Metabolic Benefits of a Carbohydrate-Restricted Diet on Hepatic Steatosis in Humans’, Cell Metabolism, 27(3), p559-571.e5. [Online]. Available at https://www.cell.com/cell-metabolism/fulltext/S1550-4131(18)30054-8 (Accessed 25 May 2018).
- Jegatheesan, P. and De Bandt, J.-P. (2017). ‘Fructose and NAFLD: The Multifaceted Aspects of Fructose Metabolism’, Nutrients, 9(3), 230. [Online]. Available at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5372893/ (Accessed 25 May 2018).
- Saw, C.L.-L., Cintron, M., Wu, T.-Y. et al. (2011). ‘Pharmacodynamics of dietary phytochemical indoles I3C and DIM: Induction of Nrf2-mediated Phase II drug metabolizing and antioxidant genes and synergism with isothiocyanates’, Biopharmaceutics and Drug Disposition, 32(5), pp289-300. [Online]. Available at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3465716/ (Accessed 25 May 2018).