The popularity of detox diets, especially liver detox diets, is on the rise not without a reason. Healthy liver means healthy body inside out. What makes liver so special? Being the largest gland and the second largest organ (after skin) in the body, liver is responsible for ensuring that all the metabolic processes in the body run smoothly. Everything that enters the body must pass through the liver to be processed - from the food you eat and the air you breathe to the soap you use and the chemicals you touch. Functioning as a filter to protect the body from harmful substances, liver helps the body use all nutrients. That means that everything ingested effects this vital organ and protecting and supporting a healthy function of the liver will guard your entire system from dangerous pathogens. This is why understanding the basics of good nutrition for the liver is necessary in order to make intelligent food choices that will benefit your life.

1. Good nutrition starts with proper digestion, and digestion starts in the mouth. So, proper chewing, slow eating in relaxed atmosphere and keeping portions reasonable are some of the very basic strategies that may completely change the way you feel long after a meal.

2. If you keep foods in as natural state as you can, you will maximize your supply of the most easily digestible vitamins, minerals and enzymes which support superior body functioning. So, miminal cooking and keeping it simple may even save you hours in the kitchen.

3. Drink plenty of water and unprocessed unsweetened fruit and vegetable juices (preferably organic and freshly squeezed) throughout the day. This simple trick will flush toxins from your body, improve your digestion and elimination, reduce the bloated feeling you may experience after eating and detoxify the liver. The only caution is with carrot juice (high levels of Vitamin A can irritate the liver), or spinach juice (high levels of oxalic acid). Best vegetable juices are celery, cucumber, broccoli and beetroot (tops and bottoms). Best fruit juices are lemon juice, apple, pineapple, pear, paw-paw, mango and melons as well as red berries. It has been suggested that it is best to drink melon juice on its own and not mixed with any other fruit.

Nutrition and Liver

The liver is the major organ responsible for regulating and responding to your body's metabolic demands. Your liver must be functioning well to maintain normal metabolism of carbohydrates, fats, and protein; it is also responsible for processing and using several vitamins. This section deals with the role and healthy liver (and a healthy, well-balanced diet) plays in these nutritional processes.

Carbohydrate Metabolism:

The most common sources of dietary carbohydrate are sugars, such as sucrose (table sugar), fructose (corn syrup), and lactose (milk sugar), and starches, such as breads, pasta, grains, cereals, fruits, vegetables, and potatoes. When you eat carbohydrates, specialized enzymes in the pancreas and gut process them to yield simple sugars (glucose, galactose, fructose, maltose).

These sugars are absorbed by intestinal lining cells, enter the portal circulation, and travel to the liver via the portal vein. During overnight fasting, blood sugar levels dip to a relatively low level, insulin secretion is suppressed, and blood insulin levels diminish. After a meal, blood sugar increases (stimulating the release of insulin from the pancreas), and insulin levels rise. Insulin, which rises in response to a meal, is the hormone that stimulates the liver to take in more glucose and to move the glucose into storage -- mainly in the form of glycogen.

With the aid of the hormones insulin and glucagon, the liver maintains a normal blood glucose level (euglycemia). Glucose that is stored in hepatocytes is called glycogen. It is used as a reservoir during times when carbohydrate intake is low (fasting or starvation). The liver can also manufacture glucose from proteins or fats. Abnormalities in blood glucose level can result from an insulinoma or diabetes mellitus (sugar diabetes). In liver disease the body can have a difficult time regulating the blood glucose level, usually leading to hypoglycemia (low blood glucose). Although the liver can store considerable amounts of glycogen, it is the first energy source used during periods of prolonged fasting or caloric deprivation, and it can be depleted rapidly. After glycogen, the body taps other energy sources -- including protein from muscles and other organs and fat.

Protein Metabolism:

We take in dietary protein from dairy products, soy (including tofu, tempeh, soy milk), nuts and seeds, eggs, fish and seafood, produce, and meats. Enzymes produced by the pancreas and intestine break down the protein into its amino acids and small peptides. The intestine rapidly absorbs the amino acids with specific transport systems within its lining cells and then delivers the amino acids to the liver via the portal vein. When they reach the liver, they are used for energy or for making (synthesizing) new proteins. The newly synthesized proteins perform specific body functions.

The liver produces all of the proteins except for the proteins synthesized by the immune system (called gammaglobulins or immunoglobulins). It does this by reassembling amino acids into protein. The main protein produced by the liver is called albumin.

Normal albumin in the bloodstream is important for many physiologic functions. One of these functions involves the normal maintenance of fluid pressure in the arteries and veins. When the protein level falls below a certain point the fluid in these vessels can leak out and pool in the abdominal or thoracic cavities. This fluid is called ascites when it occurs in the abdominal cavity, pleural effusion when it occurs in the thoracic cavity. (a more detailed explanation of ascites will follow). Albumin also functions to "carry" other compounds through the bloodstream. These compounds include calcium, vitamins, hormones, fatty acids, many drugs, and bilirubin.

A consistent finding with liver disease is a low protein level (hypoproteinemia). This low level usually occurs only when the liver has been severely diseased for a prolonged period of time, because of the great reserve capacity of the liver to produce more albumin.

To support your liver function, try to avoid heavy proteins, such as red meats and nuts. These are very potent foods and require a lot of effort to digest; nutritionally excellent in moderation, but often high in fats and toxins. Meat and nuts will take a minimum of 8-10 hours to be digested. Trying to avoid burdening your digestive system, especially liver, it is a good idea to not eat heavy proteins in the evening. If you can, choose plant protein sources, such as legumes, soybeans, tofu and tempeh. Fish and seafood, white poultry meat are also easier to digest than red meat and fatty fish. Add some vegetables and whole unprocessed grains to your meal for complete amino acid profile which will support good digestion.

Fat Metabolism:

In general, fats are neutral lipids (triglycerides), acidic lipids (fatty acids), and sterols (cholesterol, plant sterols). Triglycerides (dairy products, meats, oils, butter, margarine) are the most common type of dietary fat and represent a major source of energy. The liver is uniquely suited to regulate and process triglycerides.

Dietary triglyceride is digested in the intestine by lipase, an enzyme secreted by the pancreas in response to meals. The liver regulates concentration of fats or fatty acids in the blood that come from the diet and from body stores. Bile, secreted by the gallblader, makes the digested fat soluble and promotes its absorption. Absorbed fat is then repackaged and transported into blood, where the liver ultimately removes it from the circulation.

Interestingly, you can eat a fat-free diet and still get fat into your liver. Liver has a unique ability to convert excess amounts of carbohydrates and proteins into fatty acids. The liver also manufactures and processes cholesterol from this fat. Liver disease may be associated with both high or low blood cholesterol levels. In general, as liver disease progresses in patients with hepatitis C, the blood level of cholesterol drops.Cholesterol is necessary for many functions, particularly the sex hormones and steroids like cortisone. Excess fatty acid accumulation in the hepatocytes is called lipidosis.

Fat that reaches the liver is processed in three ways:

(1) stored as fat droplets in liver cells
(2) metabolized as a source of energy
(3) repackaged, secreted back into blood, and delivered to other cells in the body.

Bile:

The liver produces and secretes a fluid (bile) that enters the intestine to aid in digestion and absorption. Bile is clear yellow to golden-brown and contains water, electrolytes (salts), cholesterol, bile salts (detergents), phospholipids, and proteins. Bile helps to activate enzymes secreted by the pancreas and is essential for the digestion and absorption of fat or fat-soluble vitamins.

Vitamins:

The liver plays a role in several steps of vitamin metabolism... Vitamins are either fat-soluble (Vitamins A, D, E, and K) or water-soluble (Vitamin C and the B-complex vitamins).

Patients with advanced liver disease may become deficient in water-soluble vitamins, but this is usually due to inadequate nutrition and poor food intake. Vitamin B12 storage usually far exceeds the body's requirements; deficiencies rarely occur due to liver disease or liver failure. When dietary intake drops, however, thiamine and folate commonly become deficient. Oral supplementation is usually all that you need to restore thiamine and folate stores to the normal range.

Fat-soluble vitamins require not only adequate dietary intake but also good digestion and absorption by the body. That's why normal production of bile is essential. Bile in the gut is required for the absorption of fat-soluble vitamins into the body because these vitamins are relatively insoluble in water. Bile acts as a detergent, breaking down and dissolving these vitamins so they may be properly absorbed.

If bile production is poor, oral supplementation of vitamins A, D, E, and K may not be sufficient to restore vitamin levels to normal. The use of a detergent-like solution of liquid vitamin E (TPGS) improves the absorption of vitamin E in patients with advanced liver disease. The same solution may also improve the absorption of vitamins A, D, and K if the latter are taken simultaneously with the liquid vitamin E.

Detoxification

Detoxification in the liver occurs in three ways:

* Filtration of blood to remove toxins, especially bacteria and bacterial breakdown by-products in blood coming from the intestines.

* Production and secretion of bile from the gall bladder carries toxins into the intestine where the bile is absorbed by fibre and excreted. Bile also emulsifies dietary fats and fat-soluble vitamins, facilitating their absorption.

* Enzymatic neutralisation and binding of toxins to facilitate detoxification and removal of unwanted chemicals. This last step is actually a 2-stage enzymatic process. The first stage is called phase I detoxification1 where liver enzymes either directly neutralise chemicals, or convert them into intermediate forms that are further processed by phase II enzymes. The phase I process involves a group of almost 100 enzymes that are collectively called cytochrome P450. Within this system enzymes target specific chemicals, but they work with varying efficiency, ensuring there is a back up. The activity of the cytochrome P450 system varies between individuals, which probably explains the variability in susceptibility to certain diseases such as lung cancer in smokers.

Cytochrome P450 requires a number of nutrients to function effectively, including copper, magnesium, zinc and vitamin C1. If these nutrients are deficient more toxins are available to cause ongoing damage. In phase II detoxification, a process called conjugation results in protective compounds being bound to toxins by phase II enzymes. The result is neutralisation of toxins and easier excretion through the bile or via the kidney. Glutathione is a conjugating compound that converts hard to remove fat-soluble toxins into water-soluble forms that are excreted via urine. Other phase II pathways involve chemical processes such as methylation, sulfation and acylation, which neutralise toxins generated by the action of drugs and environmental toxins (eg pesticides, food preservatives and dyes).

The ability of the liver to detoxify depends on the relative health of the liver and previous exposure to toxins. Adequate nutrition is critical to the health of the liver and the removal of toxins. Fibre-deficient diets impair the removal of toxins carried in bile. The cabbage family of foods, including Brussels sprouts and broccoli, contain indole compounds that stimulate phase I and II enzymes. Citrus fruits contain limonene compounds that induce enzymes that protect against environmental toxins. Vitamin C - rich foods also stimulate cytochrome P450 enzymes.

Naturopathically, impaired liver function, often called sluggish liver, is seen as an underlying contributor to conditions such as autoimmune disorders and allergies. Sluggish liver can have an adverse effect on health even when liver disease and damage are not directly demonstrated. Symptoms include intolerance to fats, intolerance to certain chemicals, foods and drugs, sluggish digestion, nausea, and chronic constipation2. Impaired liver function is often associated with drug and alcohol abuse, past infections, and exposure to medical drugs and environmental pollutants. Naturopathic treatment involves implementation of a proper dietary regimen and the use of nutrient supplementation and herbal medicines to support the liver and to facilitate digestion and detoxification. Herbs can also help to repair the liver and protect against further damage.

Herbal liver tonics are typically cholagogues(stimulate the flow of bile from the liver) or choleretics (stimulate the production of bile by the liver). They can also be depurative (stimulate hepatic detoxification) or hepatoprotective (protect the liver against toxins).

Sources:

"Living with Hepatitis C: A Survivor's Guide" by Gregory T. Everson, M.D., and Hedy Weinberg. 1997, Hatherleigh Press.
Murray MT, Pizzorno J.Encyclopedia of Natural Medicine 2nd Edition. Prima Publishing 1998.
Mills, S Bone K.Principles and Practice of phytotherapy Churchill Livingstone 2000.
Machlin LJ.Handbook of Vitamins. Marcel Dekker 1991.
Murray MT. The Healing Power of Herbs. 2nd Edition. Prima Publishing 1995.
Mowrey, DB. Herbal Tonic Therapies. Keats Publishing 1993.
Kirchhoff R et al.Increase in choleresis by means of artichoke extract. Phytomedicine 1994; 1:107-115.
Petrowicz O et al.Effects of artichoke leaf extract on lipoprotein metabolism in vitro and in vivo. Atherosclerosis 1997; 129:147.
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