http://www.hepatitis.org.uk/s-crina/liver-f3-main3.htm
The liver is the master organ for creating optimal nutrition for all the 50 trillion cells in your body. The liver is the body's largest organ, weighing three to five pounds in adults. It uses 12 - 20% of the body's total energy, and it must generate this energy to it's own cells. The liver routinely performs over 500 known functions to regulate your cell's metabolism. It is the "alchemical wizard" of the body, transforming toxins into harmless chemicals for excretion, and digestively absorbed nutrients into the proper biochemical forms your cells can use to function. Yet the liver is probably the organ most assaulted by toxic modern lifestyles, full of pollution, stress, junk foods, drugs, etc. In the US 40000 deaths a year are due to liver disease. Yet most people will never suffer from hepatitis, cirrhosis, or jaundice, the "classic" liver diseases. Toxic modern lifestyles may however promote "subclinical" liver disfunction. And, as this review will make clear, no matter how good your diet and digestion, if your liver does not perform its many jobs properly, your cells can still be grossly malnourished. Optimal nutrition is a function, not just of what we eat and digest, but of how well the liver bio-transforms incoming food nutrients into forms that the bloodstream can transport to all the body's cells, and that the cells can use to perform their metabolic functions.
Key Liver Functions
1. The liver converts the thyroid hormone thyroxin (T4) into its more active form tri-iodothyronine (T3). Thyroid hormones act as the body's thermostat, regulating the rate at which virtually all biochemical reactions occur in the body. Inadequate conversion of T4 to T3 by the liver may lead energy-depleting hypothyroidism, leading to chronic fatigue, weight gain, poor memory and a host of other problems.
2. The liver creates Glucose Tolerance Factor (GFT) from chromium, niacin and possibly glutathione. GFT is needed for the hormone insulin to properly regulate blood-sugar levels. Due to its critical role in facilitating amino acid entry into muscle cells, GFT empowered insulin is also a necessary co-factor for Growth Hormone to be effective in promoting muscle growth in response to athletic training programs.
3. The liver manufactures bile salts. These are used to emulsify fats and fat soluble vitamins (A,D,E, and K) for proper digestive absorption. The liver also removes some fat-soluble toxins from the body by first dissolving them in bile salts, then dumping the bile and toxin mixture into the intestine for eventual fecal excretion.
4. The liver activates B vitamins into their biologically active coenzyme forms. B1 must be made into thiamin pyrophosphate, B2 into flavine adenine dinucleotide, B3 into nicotinadenine dinucleotide, etc. The plant vitamin A precursor beta carotene must be turned into real vitamin A. Other nutrients, such as iron and copper, must be changed by the liver into their appropriate bloodstream transport or storage forms, such as ferritin or ceruloplasmin. Virtually every nutrient, whether it be vitamin, mineral, amino acid, must be biotransformed into its proper biochemical form in which the nutrient may be stored, transported or used in cellular metabolism. If the liver does not properly activate nutrients into their bioactive forms, then even the most well-absorbed, high potency, broad spectrum supplement will be useless at best and possibly even mildly toxic.
The forms in which nutrients are found in supplements and foods are NOT the final, active biochemical forms used by the cells. And even if you do get the active coenzyme form of a nutrient from a food or supplement, it will usually be broken down during digestion. So there's no getting around the critical role of the liver in bio-activating the nutrients we get from foods or supplements.
5. The liver stores various nutrients, especially A, D, B12 and iron, for release as needed.
6. The liver manufactures carnitine from lysine and other nutrients. Carnitine is the only known bionutrient which can "escort" fats into the mitochondria, where the fats may be "burned" to generate ATP bio-energy. The mitochondria are microscopic "power plants" found in each of the body's 50 trillion cells - as many as 1000 per cell! These mitochondria generate 90% of the ATP bio-energy that powers every aspect of our life at the cellular level.The heart muscle "burns" fats to make ATP almost exclusively, and is extremely sensitive to cellular carnitine deficits. The muscles of well trained endurance athletes will "burn" fats to supply up to 70% of their fuel needs. Carnitine is also necessary to get branched-chain amino acids (BCAA's) into the mitochondria. BCAA's, supplied either from breaking down existing muscle tissue or supplements, are known to provide a major portion of muscle cell fuel needs during prolonged, intense athletic training or performance.
7. The liver converts lactic acid from a toxic waste to an important storage fuel. Lactic acid is produced when glucose (sugar) is metabolized through the glycolytic energy production cycle, and may irritate nerves and muscles if it accumulates to excessive levels. However, a healthy liver will extract lactic acid dumped into the bloodstream by hard-working muscles and convert it into the important reserve endurance fuel glycogen.
8. The liver serves as the main glucose buffer, preventing high or low extremes of blood sugar. It is the key regulator of blood sugar between meals, due to its manufacture, storage and release of glycogen. Glycogen is the starch form of glucose in which the body can store a half days sugar supply. When the blood sugar is low, a healthy liver converts stored glycogen into glucose, releasing it into the bloodstream to raise blood sugar levels. When blood sugar is to high, the healthy liver will remove much of it, converting the excess into stored glycogen or fat.
9. The liver can make glucose from dietary or body-derived amino acids. This process called gluconeogenesis or "the making of new glucose", ensures adequate brain and muscle carbohydrate fuel supplies even when the diet provides little or no carbohydrates. The liver produces as much as 20-25% of the blood sugar and endurance athlete's muscles might burn during intense training or competition by converting the amino alanine (released from muscle tissue) into glucose.
10. The liver is the chief regulator of protein metabolism. It converts different amino acids into each other as needed. The liver also synthesizes creatine from the aminos glycerin, arginine, and methionine. If not for the super high energy biochemical creatine phosphate, sprint-type athletics would be biologically impossible.
11. The liver produces cholesterol and packages it into different forms for blood transport : HDL, LDL, VLDL. Essential fatty acids, such as linoleic acid, GLA, EPA, and DHA, must also be properly packaged by the liver into appropriate lipoprotein forms (VLDL) to allow transport through the blood to the 50 trillion cells using the fatty acids.
12. The liver is the main poison-detoxifying organ in the body. It must break down virtually everything toxic to the body- from metabolic wastes, to insecticide residues, drugs and alcohol industrial and food processing chemicals, etc. Failure of this liver function will usually cause death in twelve to twenty-four hours. The liver uses a relatively small number of enzyme- systems - called " Mixed Function Oxidases" - to detoxify the 10.000 or more chemicals polluting modern food, air, and water. Ironically, in metabolizing some toxic chemicals through its standard limited repertoire of detoxifying processes, the liver may inadvertently convert a toxic substance into an even more damaging toxin!
13. The liver must dispose of ammonia, an extremely toxic by-product of protein metabolism. The amino acids arginine and orthinine are used by the liver to control ammonia levels. Ammonia can cause brain irritation and even death, at surprisingly low levels.
14. The liver is the main organ for breaking down hormones after they have served their messenger function to their target cells. For example, if the liver does nor break down insulin quickly enough, hypoglycemia results as the still circulating insulin continues to lower blood sugar. If the liver does not metabolize estrogen properly, PMS will result. Failure to dispose of adrenaline (the "fight" or"flight" hormone) after it has outlived its usefulness may lead to chronic irritability and temper explosions.
This brief review, which has not even touched on other key liver functions, such as immune functions and blood clotting protein manufacture, should make clear the central role of the liver in promoting optimal cellular nutrition.
A brief survey of mild liver dysfunction symptoms sounds like a description of "normal" modern life. These might include chronic fatigue and feeling tired after meals. Depression, mood instability, and irrational anger and temper flare-ups may be liver related. PMS symptoms, including breast soreness and sensitivity, depression, hypoglycemia and irritability, may be liver related. Morton Biskind, M.D., published several articles in endocrinology journals in the early 1940's linking PMS to a B-vitamin and protein deficient liver's difficulty in de-activating estrogen. Nausea, dietary fat intolerance, foul smelling gas, swollen belly, loss of appetite, constipation and diarrhea are some of the digestive toxic-liver symptoms. Aching joints and muscles, sore feet, psoriasis, and slow wound healing are common dysfunction symptoms. Headaches (especially behind the eyes,) insomnia, difficulty awakening, poor memory, and difficulty concentrating are possible brain liver symptoms.
Who Is At Risk for Subclinical Dysfunction?
1. People routinely consuming large amounts of overheated, hydrogenated, "junk food" fats-- for example, French fries, fried chicken, doughnuts, chips, etc. These heated "junk foods" are a major source of liver-toxic lipid peroxides (rancid fats) and trans-fatty acids (abnormal structure fats). Lipid peroxides are powerfully immune suppressive, and damage liver cell membranes. Trans-fatty acids suppress production of PGE1, a major liver-protecting anti-inflammatory prostaglandin.
2. Coffee drinkers. Carcinogenic hydrocarbons are produced during roasting, and dark roasts are the worst offenders. Also, coffee is grown entirely outside the U.S. and is often therefore sprayed with high levels of pesticides that are not even allowed to be used inside the U.S. Only a tiny fraction of coffee imported is checked for even some of the pesticides it is commonly sprayed with.
3. Regular alcohol users. The liver converts alcohol into toxic acetaldehyde during its alcohol detoxification process. Acetaldehyde inhibits PGE1 production, is a powerful free radical inducer, and is largely responsible for the liver, brain, heart, kidney, skin and blood vessels lining damage associated with chronic alcoholism.
4. Smokers. While many people are aware of smoking's negative effect on the lungs, less consideration is usually given to its effects on the liver. Tobacco and marijuana smoke are rich airborne stews of toxic benzpyrene, polycyclic aromatic hydrocarbons, cyanide, acetaldehyde, tars, acrolein, etc. Since these get into the bloodstream through the lungs, the liver must detoxify them. And virtually all the constituents of smoke are known to be at least mildly liver-damaging. [Psyche: switch to an additive free tobacco, preferably organic!]
5. People regularly driving on crowded, exhaust-filled roads and highways. Auto and diesel exhaust contain dozens of liver damaging poisons the liver is forced to detoxify including lead, sulfur, and nitrogen oxides, acetaldehyde, cadmium, peroxyacetylnitrile, and more.
6. Women using birth-control pills. In some cases, even as little as two or three weeks of use have been documented to ruin the ability of the liver to detoxify naturally produced estrogen. The livers of women on B vitamin/protein deficient diets may have difficulty metabolizing estrogen to non-toxic estriol, leaving it instead in the form of liver toxic estradiol. Estradiol is the form associated with hyper emotional states including explosive temper and obsessive-compulsive tendencies.
7. Candida Patients. Candida yeast ferments dietary sugars into liver-toxic acetaldehyde in the process of turning sugar into energy. Candida also seems to increase gut and urinary levels of ammonia, another liver toxin.
8. Arthritis, rheumatism, and other chronic pain sufferers who were routinely exposed to higher than normal levels of pesticides. Pesticides such as DDT, Aldrin, chlordane, lindane, 2,4,5T dioxin, and toxaphene can cause chronic liver damage, even at body levels measured in parts per billion, and tend to accumulate in body fat over a lifetime.
9. Farm workers, produce handlers, and pest control workers are routinely exposed to higher than normal levels of pesticides. Pesticides such as DDT, Aldrin, chlordane, lindane, 2,4,5T dioxin, and toxaphene can cause chronic liver damage, even at body levels measured in parts per billion, and tend to accumulate in body fat over time.
10. Industrial and service workers routinely exposed to heavy metals (lead, cadmium, mercury), radioactive chemicals, hydrocarbon solvents such as sulfuric acid and mixes like piranha, TCE, paint sprays and beauty parlor chemicals.
11. Gas station workers and auto mechanics. Gasoline, diesel fuel, motor oil, degreasing agents etc. are all liver toxic and may be absorbed through the skin or by inhaling them.
12. Those on long term prescription drug therapy. Dilantin, Phenobarbital, Nizoral etc. are some of the many potentially liver toxic drugs. Those regularly abusing drugs illegal and legal are at risk.
13. Athletes using anabolic-synthetic variations of male hormone testosterone. Serious liver damage is a medically recognized major side effect of chronic steroid abuse.
This list is by no means exhaustive, but it should offer some clues as to whether the reader may be at risk for mild or severe chronic liver damage.
Therapy That Protects the Liver
Fortunately modern nutritional science has discovered many nutritional measures to promote optimal liver function and detoxification, even in the presence of unavoidable toxins. A major liver protecting nutrient is vitamin E. E is generally recognized as the major lipid fat-soluble antioxidant in human tissue. As a free radical/antioxidant expert Stephen Levine has noted, toxic xenobiotic (foreign to the body) chemicals that may damage the liver during detoxification fall into four main classes:
1.Toxins that are themselves radicals or contain free radicals.
2.Toxins that are very reactive, and though nor free radicals themselves, cause radicals to be formed in target molecules, e.g. ozone.
3.Toxins that can spontaneously yield free radicals in the body, e.g. brain chemicals such as 1-dopa.
4.Toxins that are metabolically converted to radicals derivatives in the body, e.g. carbon Tetrachloride, acids and other solvents, etc. As early as 1973, N.R. Diluzio published studies demonstrating that many liver toxic compounds caused their damage through creation of lipid peroxides (rancid fats) in liver cells, and that this damage could be offset by supplementary vitamin E. Fatty infiltration, in which streaks of fatty material interpenetrate the liver's structure, is a common feature in alcoholism and in various liver diseases.