You need adequate stomach acid to kill opportunistic pathogens, help properly digest food and maintain optimal health. Stomach acid plays a key role in the digestion of protein, carbohydrates and fat. The breakdown and absorption of nutrients occurs at an optimum rate only within a narrow range of acidity in the stomach. If there isn’t enough acid, the normal chemical reactions required to absorb nutrients is impaired. Over time this can lead to diseases such as anemia, osteoporosis, cardiovascular disease, depression and more.
There are four primary consequences of low stomach acid and acid stopping drugs:
The mouth, oesophagus and intestines are home to between 400-1,000 species of bacteria. However, a healthy stomach is normally almost completely sterile because stomach acid kills bacteria. The low pH (high acid) environment of the stomach is one of the major non-specific defense mechanisms of the body. When the pH of the stomach is 3 or lower, the normal between-meal “resting” level, bacteria don’t last more than fifteen minutes. But as the pH rises to 5 or more, many bacterial species can avoid the acid treatment and begin to thrive. So high stomach acid provides a two-way barrier that protects the body from pathogenic bacteria: first, stomach acid prevents harmful bacteria that may be present in the food or liquid we consume or the air we breathe from entering the intestine; at the same time, stomach acid also prevents normal bacteria from the intestines to move into the stomach and oesophagus, where they could cause problems.
The second role of high stomach acid (HCl) is to trigger the production of pepsin when food is eaten. Pepsin is the enzyme required to digest protein. If HCl levels are depressed, so are pepsin levels. As a result, proteins don’t get broken down into their component amino acids and peptides. This can lead to a deficiency of essential amino acids, which in turn may lead to chronic depression, anxiety and insomnia. At the same time, proteins that escape digestion by pepsin may end up in the bloodstream. Since this is not supposed to happen, the body reacts to these proteins as if they were foreign invaders, causing allergic and autoimmune responses.
As acid declines and the pH of the stomach increases, absorption of nutrients also becomes impaired. Decades of research have confirmed that low stomach acid – whether it occurs on its own or as a result of using antacid drugs – reduces absorption of several key nutrients such as iron, B12, folate, calcium and zinc.
Low stomach acid causes bacterial overgrowth in the stomach and other parts of the intestine. Bacterial overgrowth causes maldigestion of carbohydrates (due to decreased pancreatic enzyme secretion), which in turn produces gas. This gas increases the pressure in the stomach, causing the lower oesophageal sphincter (LES) to malfunction. The malfunction of the LES allows acid from the stomach to enter the oesophagus, thus producing the symptoms of heartburn and GERD.
By lowering stomach acid and increasing stomach pH, acid-suppressing drugs increase the risk of Helicobacter pylori infection and subsequent development of duodenal or gastric ulcers.
It’s entirely plausible that acid-stopping medications - proton pump inhibitors (PPIs), H2 blockers and acid neutralizers - increase the risk of stomach cancer by at least two distinct mechanisms: