Liver facts

Location of liver and its main functions

The liver is one of the largest organs in your body, with liver anatomy measurements indicating a weight of just over 1kg (2.2lb). It is shape much like an American/Rugby football that is flat on one side. It is located under your rib cage, and above and largely to the right of the stomach. Over a litre (1 quart) of blood passes through the liver every minute.

This absolute powerhouse has a number of vitally important functions, but unfortunately, unlike the lungs and kidneys, we have only one liver, so you better look after it well. The liver’s main functions include:

•   Maintaining blood sugar levels by carbohydrate metabolism, making glucose when needed
•   Defence against microbes, metabolism of ethanol and the detoxification of drugs and other noxious substances
•   Making bile for digesting food, particularly the breakdown of fats, inactivation of hormones and breakdown of proteins and red blood cells (erythrocytes)
•   Controlling the formation and destruction of blood pigment haemoglobin and making blood proteins, including those need for blood clotting
•   Producing heat to warm the blood that passes through it – the liver is the main heat-producing organ of the body
•   Removing environmental toxins (eg pesticides and fertilizers) from the blood stream and inactivating these toxins
•   Filtering out toxins produced during metabolism (eg ammonia formed from the metabolism of amino acids) and converting them into safe chemicals (eg urea) for excretion
•   Storage of some water-soluble vitamins, eg vitamin B, niacin, riboflavine, folic acid and pyridoxine
•   Synthesis of vitamin A from carotene and the storage of some minerals (eg iron and copper) and fat-soluble vitamins (A, D, E and K)

Most detoxification processes start in the liver and liver cells contain more detoxifying enzymes than any other tissues in the body. Everything you eat or drink (with the exception of some small fat particles) is readily absorbed from the intestines and carried straight to the liver in the hepatic portal vein. The exceptions (ie small fat particles) enter the lymphatic system instead.

Each and every minute of the day approximately one-third of the total blood flow passes through rows of liver cells separated by spaces (called the sinusoidal system) and the blood flowing through it is filtered and harmful substances sieved out and inactivated by the liver. The sinusoidal system also contains highly specialized Kupffer cells that break down toxic matter and for the most part render it harmless.

It is the cleanser and filter of the blood stream and this blood detox is of vital importance. Unfortunately some substances are too toxic for the liver to neutralise and either these damage the liver, or the liver packs them in the liver’s fat cell where they remain, or they spill into the bloodstream and potentially do damage other body systems.

The liver’s biochemical pathway

The liver’s detoxification enzymatic pathways are known as phase I and phase II reactions, and are used by the liver to eliminate or neutralize harmful substances. Ideally these phases should occur in a rapidly coordinated action with the outputs from phase I reactions properly passed on to the phase II pathways and then excreted from the body.

Phase I detoxification

There are at least fifty enzymes in ten enzyme families governed by 35 different genes that allow Phase I reactions to take place. The major enzymes are known as the cytochrome P450 super family of enzymes (often abbreviated as CYP Enzymes or CYP 450). The highest concentration occurs in the liver, which is the most active site of metabolism in the body.

The lungs and the kidneys are secondary organs of biotransformation, with about one-third of the liver’s detoxification capacity. The brain, adrenal cortex, intestines, spleen, testes, muscles, heart, and skin also contain small quantities of CYP 450.

During this phase I process, with the help of these high liver enzymes, non-polar (ie electrically neutral) non water-soluble chemicals are converted into relatively polar (ie electrically charged) compounds by adding a polar or reactive chemical group to the compound.

This electrically charged compound now wants to, in fact has to bind (conjugate) with another small molecule to become electrically neutral again. This is achieved through a number of chemical reactions including oxidation, reduction, hydrolysis, dehalogenation and hydration.

Phase II detoxification

Phase II reactions involve several pathways in which molecules from phase I detox undergo conjugation in the liver to form metabolites that are water-soluble. Smaller molecules are then excreted from the body in the urine or, if the chemicals are of high molecular weight, these are excreted through bile (and the gallbladder) which is then passed into the intestine.

For efficient phase II detoxification, ample amounts of minerals, vitamins and sulphur bearing amino acids such as cysteine and taurine are required. Adequate quantities of glutamine, glycine, inositol and choline are also needed, as are large amounts of glutathione – the most powerful antioxidant and liver protector in our body.

Detoxification imbalances

CYP 450 enzymes are greatly affected by dietary, environmental and lifestyle factors and there is a great degree of variation among people in their ability to biotransform toxins. This variability of phase I functioning can be as much as fivefold, even among healthy individuals.

While it is quite normal for phase I and phase II to be out of balance, it is vitally important that the level and duration of this imbalance is kept to an absolute minimum. An imbalance between the phase I/phase II pathways will result in a build-up of phase I metabolites (ie electrically charged particles) looking for something to bind to.

Unless the phase I metabolites are passed quickly to phase II and neutralised, these electrically charged particles end up as free radicals which can wreck a lot of havoc in our bodies. They have a great potential to damage our liver cells, may cause significant other cellular damage, can cause irritation to the immune system, and directly damage our DNA.

It is important for the phase II detoxification pathway to work well so that these chemicals do not hang around in our liver cells for long. This means that we must have plenty of antioxidants available to our liver cells to mop up these free radicals, and to help build up immune system functions.

Unfortunately there are many substances (eg drugs) that can change the delicate balance between these two pathways, but there are also many foods that can have an impact. For example, grapefruits contain cyp3a4 inhibitors. cyp3a4 enzymes are responsible for catalyzing more than half of all microsomal drug oxidations. Similarly, CYP1A2 and related enzymes are sensitive to caffeine in the bloodstream.

More worrying is that the phase I/phase II balance can be affected by overwhelming exposure to toxic substances for which the body has no detoxifying mechanisms, resulting in the destruction of detoxification enzymes. If we are exposed to a large amount of toxins, and/or we are deficient in the co-factors needed for detoxification to occur, a build-up of toxins will result.

This means a large amount of toxins will spill into the bloodstream which over time can lead to hyper-stimulation and exhaustion of the immune system. This may result in a tendency to develop allergies, autoimmune conditions or repeated infections. In these cases, and with the toxins we’re exposed to as part of our modern lifestyles, there are many many benefits to be gained from doing a proper detox.

The importance of food

Liver cells process digested food and change it into substances that the body will need, then store them until they are required. If these substances are needed they will pass out of the cell into the sinusoid and thus to the central vein. Fats are either stored in the liver or sent back into the circulation of the fat depots.

More frequently fats are combined with protein – lipoprotein – to be used as an energy source. Proteins – the albumen, globulin and fibrinogen for the plasma are all made in the liver. Glucose is turned into glycogen and iron combined with protein before being stored in the liver. The vitamins A, B complex, B12, D, E and K are all also stored, the reserves lasting many months.

For these processes to work, proper liver nutrition is vitally important as deficiencies of vitamins, minerals, fatty acids and amino acids can adversely affect the efficiency of Phase I and Phase II processes.

If we do not eat enough protein this specifically reduces Phase I efficiency and effectiveness. Inadequate consumption of protein, carbohydrate, fat, and micronutrients intake will cause the liver to obtain its nutrients from elsewhere in the body. It will do this by breaking body tissue to produce the energy it needs, thereby creating an even larger toxic burden.

The detoxification process requires large amounts of caloric energy and insufficient calorie intake decreases overall detoxification function. Caloric energy mainly comes from the food we eat, and in the process the liver produces a lot of heat that is needed to keep our bodies at the right temperature.

The simplest way to try and maintain a phase I/phase II balance is following a good detox diet plan and making the use of several botanicals. There is more information on this website on which foods to eat and which foods to avoid for a natural liver cleanse and detoxification.

Gallbladder location and function

The gallbladder is a small muscular sack that stores bile to make sure it is available in larger quantities for secretion when a meal is eaten. The liver manufactures about 500 millilitres (17oz) of bile a day, which a solution of cholesterol, bile salts and pigments.

When food enters the digestive system the hormone cholecystokinin (CCK) signals the gallbladder to release concentrated liquid bile into the small intestine and it also signals the relaxation of the valve at the end of the common bile duct (the sphincter of oddi) to allow the bile to enter the small intestine.

Once in the intestines, the bile emulsifies (breaks down) fats in the meal which is essential for digestion and the absorption of fat-soluble vitamins. Some of the bile is reabsorbed, while the rest remains and which gives the particular colour to the faeces.

Helping your liver help you

More than ever before in the history of humanity, we need to have healthy livers to break down the chemicals that have crept into our environment. The many different types of pollution and toxins can easily overload the liver’s detoxification systems.

Many diseases are blamed on a variety of factors but they can all be traced back to a common root cause: toxicity. Exposure of toxins to our body’s internal systems and organs, and the subsequent toxic accumulation causes untold health problems, both immediate and long term.

Detoxification techniques and balancing methods make it possible for us to rebuild our bodies and immune systems. Common sense protective measures allow us to maintain our health, resulting in longer lives, with significantly lower risk of degenerative diseases and other illnesses.

If you nourish yourself with nutritious, freshly prepared foods you will give your liver its best chance of eliminating any poisonous chemicals that it does encounter. You’ll also be giving it the time to deal with the backlog of toxins it has had to store in its own liver cells.

However often this is insufficient and many people use one or more comprehensive detoxification products (such as liver supplements) to try achieve full body wellness. We need to give the liver a break and begin to work with it, rather than adding to its problems and to help prevent the onset of many chronic and debilitating illnesses.

If we have done damage to it, or even suspect we have done damage to it, you need to undertake liver repair and liver regeneration so that the liver’s two primary detoxification pathways can continue to function properly.

But how would you know that you need to give the liver a break? There are a range of symptoms associated with toxicity you can look out for yourself, and there are also specific liver function tests you can ask for from your doctor or health professional that will tell you about the health of your liver.