Once the bolus leaves the mouth, it travels down the oesophagus and into the stomach to continue the process of digestion. The composition of the muscular structure changes from skeletal muscle (voluntary), towards smooth muscle (involuntary), as we move from the mouth to the stomach.
This would suggest that all the oesophagus facilitates, is the transport of the bolus into the stomach.
However, it is a potential dysfunction at the final point of this journey, that can lead to a now common condition called Gastro Oesophageal Re-flux Disease (GERD), that if mismanaged, may have profound effects upon our digestive capacity moving forward.
GERD (The E prevails in medical terminology because of the US spelling of esophagus), may originate from a weakness in the lower oesophageal sphincter (LOS), that allows stomach acid to back-flow into the oesophagus.
This is because the LOS is not actually a true sphincter muscle in humans, but is actually the position of the diaphragm, holding the stomach in place. If the oesophagus moves upwards or downwards, allowing the stomach past the diaphragm (as can occur in a Hiatus Hernia), then symptoms of GERD may manifest. These symptoms include heartburn, difficulty swallowing and persistent coughing (especially at night).
Conventional medical management tends to focus on symptom reduction, by controlling acid production through the use of antacids, H2 receptor antagonists and PPI’s (proton pump inhibitors). The thinking being that reducing acid production, should thereby prevent back flow entering and damaging the oesophagus.
However the root cause of GERD may not be primarily an LOS dysfunction, (which may actually be a product of other mediators), but reduced stomach acid itself, in conjunction with the presence of the bacteria Helicobacter Pylori (H Pylori).
During periods of long term stress, alongside poor nutritional & lifestyle habits, and or increasing age, the output and quality of stomach acid (HCL), can start to decline. This can lead to an overgrowth of H Pylori in the stomach, where they would usually be under control, due to the acidity of the environment.
The H Pylori naturally try to escape the still harsh acidic conditions of the stomach, by burrowing into the stomach wall, which in turn can further reduce HCL output by destroying the actual Parietal cells that produce HCL.
The H Pylori also create an enzyme called Urease, which has a buffering effect on the acidity of our endogenous HCL, which further increases their protection, but reduces the stomach’s digestive and antibacterial capacity.
Reduction of HCL leads to increased carbohydrate fermentation by bacteria in the stomach, which in turn increases hydrogen gas as a by product (think burping between meals), thus causing a rise in the intra-abdominal pressure.
With this pressure increase in the stomach, the ability of the LOS to remain in position becomes threatened, and even a less acidic or a reduced amount of HCL present in the oesophagus, will cause the symptoms of GERD.
This chain of events is often caused and accompanied by long term stress, lack of physical activity, poor diet and increasing obesity, which put together over time, is the perfect storm to produce GERD.
So whilst it makes perfect sense to initially control the damaging effects of acid re-fluxing back into the oesophagus, pure symptom reduction alone (via HCL reduction), as the long term solution, may eventually become counter productive.
This is because decreasing the stomachs natural antibacterial capacity (HCL output), may be causing the actual protagonists of GERD – H Pylori - to flourish.
Once the symptoms of GERD are under control, the focus must shift towards identifying the root cause of the condition (which may be unique to each individual), and this is of vital importance if HCL reduction is indeed part of the original problem.
A long term reduction in our natural secretion of HCL presents problems for the rest of the digestive process, as the acidity of the stomach primarily affects the digestion of protein, vitamins and minerals, and also the quality of digestive secretions further downstream in the intestines.
Our next post will therefore consider nutritional & lifestyle practices to help manage and prevent the symptoms and potential causes of GERD.