The Stomach | Acidic Environment for Digestion and its Importance

The Stomach: An Acidic Environment for Digestion

After the food has been chewed and swallowed, it enters the stomach, where it is stored for an hour or two. Many people think this is when digestion takes place. This is only partly correct. Some protein and fats get digested in the stomach. The main job of the stomach, however, is to acidify your partially digested food by bathing it in a solution of hydrochloric acid.

Acidifying Your Food: Functions of Stomach Acid

• This serves two purposes:
  It sterilises your food by destroying any harmful microorganisms that you may have eaten;
•  It initiates the release of acid-linked enzymes for digestion later on, in the intestines.

Acidifying Your Food: Functions of Stomach Acid

This serves two purposes:It sterilises your food by destroying any harmful microorganisms that you may have eaten

pH Levels and Digestive Process in the Stomach

Both of these functions require relatively strong acids, with a pH below 3.0 - but this is not as strong as the stomach acids of meat-eating animals, which have a pH of around 1.0 and are capable of dissolving bones, skin, hair and other animal parts. Only when your stomach contents reach pH 3.0 will the pyloric valve - which acts as a "door" at the base of the stomach - open to let the contents out into the intestines. This is where the main part of digestion takes place.

Consequences of Low Stomach Acid Secretion

It is important to ensure that your stomach secretes enough acid and that the acid is strong enough. People with low stomach acid secretion will experience digestion problems, which will lead to diseases such as:

• Infection due to higher levels of harmful bacteria, yeast (candida) and other microbes in the intestines;
• Inflammation of the intestinal mucus membrane, arising from infection. This leads to leaky gut syndrome and, eventually, chronic inflammatory diseases such as food allergies, autoimmune disorders, eczema and asthma;
• Acid reflux due to poorly digested food being fermented by microbes. Fermentation releases gas that leads to bloating and reflux symptoms. The fermenting contents further irritate the intestinal mucus lining, leading to leaky gut;
• Stomach ailments like gastritis, stomach ulcer, duodenal ulcers (in the first section of the small intestines) and stomach cancer. These problems were previously thought to be caused by strong stomach acids. However, they have now been linked to the Helicobacter pylori bacteria, a type of bacteria that flourishes when the mucus membranes are inflamed - due to weak stomach acids;
• Poor digestion: The first important step of protein digestion is acidification in the stomach. Without adequate acidification, proteins will not be digested properly in the small intestines.
• Poor nutrition: Low stomach acidity reduces nutrient absorption, particularly the absorption of the B complex vitamins like vitamin mB12, and minerals like iron, calcium, magnesium, phosphorus, boron and zinc. Deficiency of these vital micronutrients will, in turn, further weaken the digestive system.
  
  

Importance of Proper Stomach Acidification for Digestion

It is important, therefore, to ensure that your stomach remains acidic. You can boost your stomach production of hydrochloric acid in the following ways:

• Eat a healthy diet that includes adequate complete protein, vitamin B1, vitamin C and zinc. These nutrients support stomach acid production;
• Avoid eating too big a meal, especially one that contains plenty of meat protein, which requires much more acid. The stomach may not be able to produce enough;
• Avoid foods that inhibit acid production. These include excessive amounts of carbohydrates and alcohol;
• Avoid stress, anxiety and excitement during meals;
• Make sure your thyroid function is healthy. Thyroid deficiency lowers the production of gastrin, a hormone necessary for signalling hydrochloric acid production.

Most of all, you must avoid drugs that neutralise stomach acids, such as:

• H2 histamine receptor blockers like cimetidine (Tagamet) and ranitidine (Zantac) - drugs commonly used to treat gastritis;
• Proton pump inhibitors like omeprazole (Prilosec) - drugs commonly used to treat acid reflux.

Secretion of stomach acids also tends to decline with ageing, causing malnutrition in the elderly. Seniors could benefit from supplementation of hydrochloric acid or fruit vinegars to help improve their digestion and nutrient assimilation.

This content is adapted, with permission, from Book 1 of 2 : The Wonders of Nutrition by Dr Ang Poon Liat. MBBS, M.MED (PAED), MRCP (UK PAED), FAMS, MD.