The Stomach: Key to Health
The stomach is a muscular bag in the upper part of the alimentary canal that is the primary digestive organ. The naturopathic view is that most chronic illnesses originate with dysfunction of the stomach, for which reason addressing digestive problems is of the utmost importance in recovering your health.
The function of the digestive system is to break down the complex molecules in the foods and drinks consumed and to absorb the constituent molecules that can then be used as the building blocks for all body processes. If you think of the alimentary tract as a molecular disassembly line, you may start to understand how dysfunction of the stomach sets up the rest of the digestive system for problems and how stomach problems can actually be the root cause of many seemingly unrelated ailments.
Stomach disorders are very common with data from hospitals indicating that one in every four people suffers with some kind of chronic stomach disorder. Typical symptoms of stomach problems include nausea, vomiting, bloating, burping, cramps, abdominal pain, feeling uncomfortably full after eating modest amounts of foods and indigestion, and can cause a very poor quality of life.
Whether recognised or not, ineffective stomach function can cause all sorts of knock-on effects on the rest of the digestive tract, the liver, the kidneys and in the failure to supply the raw materials required to repair and maintain the body.
The location of the stomach
The stomach is located between the oesophagus (which is a muscular tube that transports masticated boli of food from the mouth through the thorax to the abdomen) and the long digestive tube that is the small intestine. It is located on the left upper part of the abdominal cavity with the top of the stomach lying against the domed diaphragm and the pancreas lying behind.
The function of the stomach
Whilst the enzymatic processes of digestion begin in the mouth with the secretion of amylase which starts the digestion of carbohydrates, it is in the stomach that protein digestion begins.
The mucosal lining of the stomach secretes the protein-digesting enzyme, pepsin, in a precursor form known as pepsinogen to prevent it digesting the stomach lining. Pepsinogen is activated by the hydrochloric acid also produced by the stomach lining to become pepsin which starts to break down proteins. The stomach contents are churned before being released as an acidic paste known as chyme into the small intestine. The combined effect of the protein-digesting enzymes and the stomach acid also serves to kill or inhibit any bacteria and parasites present in the food and drink consumed.
The other function of the stomach is to act as a distensible storage organ which can then permit the slow release of its contents into the small intestine over a period of hours. To this end the stomach can go from an empty volume of just 50 ml to a maximum capacity of 3 litres and food can be retained in the stomach for as little as half an hour for say, an apple, up to many hours for a rich meal.
Whilst the stomach lining is protected by mucous from being damaged by the incredibly acidic conditions in the stomach (a pH of 1, equivalent to battery acid) the small intestine has no such protection. What happens is that the pancreas produces alkaline pancreatic juice full of bicarbonates and these pour into the duodenum and neutralise the acidic stomach contents as they pass into the small intestine.
It is now known that the stomach possesses 'taste' receptors that are sensitive to glutamates (such as MSG), glucose, carbohydrates, proteins and fats and which connect directly to the hypothalamus and limbic system in the brain via the vagus nerve. This allows the brain to link the nutritional value of foods to their tastes and also possibly to allocate incoming nutritional supplies.
The anatomy of the stomach
The stomach is divided into 4 regions, each of which has specialised cells and functions. The sections are the body (corpus), the fundus (the upper curvature of the organ), the pylorus (where it joins the small intestine) and the cardiac region (where the oesophagus empties into the stomach).
There are two rings of smooth muscle known as sphincters which prevent regurgitation of the stomach contents into the oesophagus (the oesophageal or cardiac sphincter) at the upper end and premature passage of the food into the small intestine at the bottom of the stomach (the pyloric sphincter).
The blood supply to the stomach is complex and comes from at least five different arterial sources. The stomach is heavily supplied by two different sets of autonomic nerves which regulate its secretions and the activity of its muscles as outlined below.
Like the other parts of the gastrointestinal tract, the stomach walls are made of the following layers, from innermost to outermost:
The lining mucosa consists of an epithelium containing gastric glands and supported on a thin layer of smooth muscle.
The submucosa is an intermediate layer composed of fibrous connective tissue and contains a plexus of autonomic nerves known as Meissner's plexus which is responsible for controlling secretions from the mucosa.
The outermost layer is muscular, and unlike the rest of the digestive tract which is composed of two layers of muscle (circular and lengthwise) is composed of three (circular, lengthwise and oblique). It is the additional oblique layer which is responsible for the ability to churn the stomach contents. The middle layer of circular muscle fibres form the sphincters (valves) and an autonomic nerve plexus known as Auerbach's plexus is found between the middle and outermost longitudinal layer which controls the muscular contractions of the stomach.
Finally, outermost is a layer of connective tissue that runs the entire length of the alimentary tract. The large involuted sac within which the abdominal contents are contained is partly suspended from the upper surface of the stomach.
The control of stomach function
The actions of the stomach are controlled jointly by the autonomic nervous system and by various digestive system hormones. These include gastrin which turn stomach function on by promoting acid and protease production and muscular churning. This hormone is produced by specialised cells within the stomach in response to distension and the presence of undigested food. Production of gastrin is turned off when the contents become sufficiently acidic (pH<4) and by the hormone somatostatin.
Other hormones such as cholecystokinin (CCK), secretin, gastric inhibitory peptide (GIP) and enteroglucagon between them act to turn off the gastric phase of digestion (reducing churning and acid production) and to activate pancreatic and gall bladder function.
The activities of the stomach are coordinated by the autonomic nervous system which controls secretions, muscular churning, and the regulation of the sphincters preventing back-flow and premature passage of contents into the duodenum. The autonomic nervous systems then further orchestrates the regulation of the passage of chyme and gall bladder and pancreatic gland empyting.
Disorders of the stomach
It had always been believed until recently that the highly acidic environment of the stomach prevented the growth of any microorganisms within. However, the work of two Australian researchers, Dr Barry Marshall and Dr Robin Warren, showed that a bacterium - Helicobacter pylori - was indeed responsible for a great many stomach disorders to the consternation of the medical community at the time. This hardy bacteria had devised ways of neutralising stomach acid thus preventing its destruction. The two researchers were subsequently awarded the Nobel prize for Medicine in 2005 for their work and Helicobacter pylori is now recognised to be the underlying cause of most cases of peptic ulcers, gastritis and stomach cancer.
Further research has shown that half the population are infected by H. Pylori, making it the most common infection in the world. It is largely associated with deprivation and rates are higher in the developing world and in immigrant communities than in the developed world where approximately one in four people carries the infection. Although the percentage of people affected increases with age with 10% affected in early adulthood and 50% of those over the age of 60 affected, most infections are thought to be acquired in childhood. Bleeding from ulcers in the stomach or duodenum may be seen in the stool as either appearing like coffee grounds or may make the faeces dark. This occult bleeding can also lead to anaemia over time.
A small protein molecule known as Epidermal Growth Factor (EGF) has been identified in saliva which appears to be controlled by dietary iodine and plays an important part in maintaining the tissues of the mouth, oesophagus and stomach. EGF promotes healing of oral and gastroesophageal ulcers, inhibits production of stomach acid, and protects the mucosa from the actions of the protein-digesting enzymes.
The nausea often experienced as morning sickness in early pregnancy is thought to be due to the bile from the gall bladder refluxing into the stomach and may be due to an incompetent pyloric sphincter.
Hypochlorhydria and hyperchlorhydria
Having too little or no hydrochloric acid in the stomach is known as hypochlorhydria or achlorhydria respectively and these are conditions which can have serious negative health impacts, although the cause may go unrecognised. Conversely, having high levels of gastric acid is called hyperchlorhydria.
Allopathic medicine maintains that the cause of many problems such as stomach and duodenal ulcers and gastro-oesphageal reflux reflux are caused by excessive production of gastric acid ie: hyperchlorhydria and so they seek to remedy this by administering antacids. Recent research, however, indicates that the gastric mucosa which secretes gastric acid is acid-resistant.
The natural medical world sees many stomach problems as being attributable to low stomach acid ie; hypochlorhydria. This means that food is retained and churned in the stomach for extended periods of time because the acid produced is not sufficient to activate pepsinogen and digest proteins. In fact, half of all fifty year olds are found to have insufficient stomach acid production. Signs include seeing food in the stool, feeling full and heavy for prolonged amounts of time after a modest meal, discomfort and burping due to the fermentation of foods within the stomach.
This finding may be due to the presence of corrosion products from dental amalgam fillings in the food eaten along with the constant swallowing of mercury-rich saliva. The presence of mercury in the stomach poisons the process of stomach acid production and the production of the hormones that control digestion in addition to causing destruction of the autonomic nerves which coordinate all the processes involved.
The unseen effects of mercury toxicity result is the growing paralysis of the muscles of the stomach and the sphincters becoming incompetent. For the pyloric sphincter this leads to premature passage of acidic chyme into the duodenum which will not be countered by the alkaline pancreatic juice and may therefore lead to the formation of duodenal ulcers. And an incompetent cardiac sphincter leads to reflux of acidic stomach contents into the oesphagus known as gastro-oesphageal reflux (GORD or GERD).
Another issue is that the body's main defence against the ingress of bacteria and parasites in the food and drink consumed is ineffective and this can lead to multiple bacterial and parasitic infections over time.
Another increasingly common problem which is now being recognised by allopathic medicine is gastroparesis. This is a partial or total paralysis of the stomach muscles involved in churning the stomach contents resulting in food being retained in the stomach and fermenting. This is often found in patients with diabetes, cancer or those who have had a stroke. The symptoms of gastroparesis include abdominal pain, a prolonged feeling of fullness after eating, abdominal bloating, nausea, vomiting after eating and a loss of appetite.
I would suggest that this is due to paralysis of the stomach muscles caused by degeneration of the autonomic nervous supply and that this is found in patients with diabetes, cancer and strokes because these diseases too are caused by chronic mercury poisoning - that they are all signs of the same underlying problem.
Gastro-oesphageal (GORD in the UK) or gastro-esophageal reflux (GERD in the US) is where the sphincter between the stomach and oesophagus has become incompetent. Symptoms include night time episodes of chest pain, a foul taste in the mouth and nausea. Prolonged GORD/GERD can result in pneumonia and a chronic cough as stomach contents are aspirated into the lungs and also in poor dental status as the teeth are dissolved by the stomach acid.
The hydrochloric acid of the stomach acid causes chemical burns of the oesophagus and these may potentially result in the medical emergency of perforation. This may occur in people who are bulimic in addition to those who have an incompetent cardiac sphincter. The causes of this are allied to, and discussed under, hypochlorhydria (see above).
The stomach and Traditional Chinese Medicine
The stomach meridian is one of the longest meridians and it starts below the mid-point of the eye on the rim of the eye socket and loops over the side of the face and then passes down the front of the neck and torso lateral to the midline and then down the front of the leg to terminate on the second toe. In this manner a second hammer toe can indicate long-standing problems with the stomach meridian.
The muscles associated with stomach as the pectoralis major clavicular, the neck muscles and brachioradialis. Pectoralis major clavicular lies between the clavicle and the front part of the upper arm and bends and turns the arm at the shoulder. Weakness of the neck muscles associated with the stomach meridian may account for some of the headaches and neck, shoulder and upper back pain experienced in fibromyalgia and CFS. The neck muscles are also associated with the drainage of the sinuses and scalp and so chronic sinus problems may be an indicator of poor stomach function. The brachioradialis muscle in the lower arm is also associated with the stomach meridian and this muscle is responsible for flexing the elbow and helping to turn the wrists. Weakness of this muscle makes it difficult to put your arm up and behind your back. This muscle is frequently found to be weak in people also suffering with insomnia and nervous tension.
The neurovascular holding points (for strengthening muscles) associated with the stomach are found half-way up the forehead above the pupils of each eye and holding these points can help to strengthen the stomach meridian. You may wish to click the link to refer to an article about Simple Energy Management Techniques for more information.
The main neurolymphatic massage points (circuit breakers for overloaded meridians) associated with the stomach are just below the breast/chest on the left hand side where an underwiring of a bra would be on a woman. This area may be tender and rubbing it will help to reset and strengthen the stomach meridian.
The stomach is governed by the solar plexus chakra which also governs all the other organs of digestion and is associated on an emotional level with self-assertion and self-esteem.
In TCM the stomach is associated with the emotions of: disgust, bitterness, greed, emptiness, hunger, reliability/unreliability, criticism contentment, disappointment, deprivation, nausea, sympathy, empathy and doubt. So any issues around these emotions may need to be addressed in order to achieve permanent resolution of chronic stomach problems.
The stomach meridian is a yang meridian partnered with the yin spleen meridian. This means that under-function by the stomach meridian places strain upon the spleen meridian which governs the immune system. This is a double-bind for fatigue sufferers with compromised digestive function and immunity.
Prevention and treatment of stomach disorders
Smoking is known to stimulate stomach acid production and to impair production of the protective mucous leading to the development of stomach ulcers in the majority of smokers. Excessive alcohol consumption too can cause stomach ulcers, gastritis and even stomach cancer. So, avoiding smoking and overconsumption of alcohol is a good place to start.
Several medications are also known to potentially cause chronic stomach problems. These include aspirin and other non steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen which are frequently taken to manage chronic pain and can damage the stomach lining causing ulcers. Other pharmaceuticals such as narcotics can interfere with stomach emptying and cause bloating, nausea and/or vomiting.
Advice includes taking time to chew your food properly and avoiding drinking with food as this dilutes the digestive juices. Also, try to take time out to eat and not to eat on-the-run. Supplementing with digestive enzymes acts as an interim measure to promote efficient digestion but should be avoided in anyone with a history of ulceration.
Careful removal of dental amalgam fillings allied with a mercury detoxification programme will permanently address the underlying cause of many stomach disorders as outlined in Chronic Fatigue, M.E., and Fibromyalgia: The Natural Recovery Plan.
Click to view a list of digestive enzymes available to order in the UK and in the US or to go to the Supplements Hub.
You might also be interested in the following:
Digestive Enzymes: Key to Health
The Scoop on Poop
The Solar Plexus Chakra
The Small Intestine
The Large Intestine and Guilt
For a protocol for restoring digestive function after chronic ill health, please refer to Chronic Fatigue, ME and Fibromyalgia: The Natural Recovery Plan.
Digestion, Digestion, Digestion and Why Health Begins in the Colon and other podcasts listed under Natural Recovery in the Audio Hub
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The stomach: Article summary
This article looks at the anatomy and functions of the stomach, disorders of the stomach including hypochlorhydria and hyperchlorhydria, gastroesophageal reflux (GORD, GERD) and stomach and duodenal ulcers. It compares the allopathic and natural medicine views of stomach disorders and the Traditional Chinese Medicine correlates of the stomach are also outlined.
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The Natural Recovery Plan Ezine September 2010 Issue 9. Copyright Alison Adams 2010. All rights reserved
Dr Alison Adams Dentist, Naturopath, Author and Online Health Coach www.thenaturalrecoveryplan.com