PART IV

Believe it or not, stomach acid isn’t there just to punish you for eating Indian food. Acid is in the stomach because it’s supposed to be there. It is found in all vertebrates. And while it isn’t necessary for life, it is certainly required for health.

Most people have no idea how many vital roles stomach acid plays in our bodies. Such misunderstanding is perpetuated by drug companies who continue to insist that stomach acid is not essential. Meanwhile, millions of people around the world are taking acid suppressing drugs that not only fail to address the underlying causes of heartburn and GERD, but put them at risk of serious (and even life-threatening) conditions.

There are four primary consequences of acid stopping drugs:

  1. Increased bacterial overgrowth
  2. Impaired nutrient absorption
  3. Decreased resistance to infection
  4. Increased risk of cancer and other diseases

I had originally intended to cover all four of these issues in this article, but as I started to write I realized it would be far too long. So I will cover increased bacterial overgrowth and impaired nutrient absorption in this article, and decreased resistance to infection and increased risk of cancer and other diseases in the next article.

A stomach full of germs

We’re not going to spend much time on this here since the connection between low stomach acid and bacterial overgrowth was the focus of Part II and Part III.

To review, low stomach acid causes bacterial overgrowth in the stomach and other parts of the intestine. Bacterial overgrowth causes maldigestion of carbohydrates, which in turn produces gas. This gas increases the pressure in the stomach, causing the lower esophageal sphincter (LES) to malfunction. The malfunction of the LES allows acid from the stomach to enter the esophagus, thus producing the symptoms of heartburn and GERD.

Bacterial overgrowth has a number of other undesirable effects, including reducing nutrient absorption, increasing inflammation, and raising the risk of stomach cancer. Studies have confirmed that proton-pump inhibitors (PPIs) can profoundly alter the gastrointestinal bacterial population by suppressing stomach acid. Researchers in Italy detected small bowel bacterial overgrowth (SIBO) in 50% of patients using PPIs, compared to only 6% of healthy control subjects. The prevalence of SIBO increased after one year of treatment with PPIs.

Well-fed but undernourished

Stomach acid is a prerequisite to healthy digestion. 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.

Macronutrients

Stomach acid plays a key role in the digestion of protein, carbohydrates and fat. When food is eaten, the secretion of stomach acid (HCL) triggers the production of pepsin. 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. I’ll discuss this more below.

Micronutrients

We can eat the most nutritious diet imaginable, packed with vitamins, minerals and other essential nutrients, but if we aren’t absorbing those nutrients we won’t benefit from them.

As acid declines and the pH of the stomach increases, absorption of nutrients 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.

Iron

Iron deficiency causes chronic anemia, which means that the body’s tissues are literally starving for oxygen.

In one study, 35 of 40 people (80 percent) with chronic iron-deficiency anemia were found to have below normal acid secretion. Iron-deficiency anemia is a well-known consequence of surgical procedures that remove the regions of the stomach where acid is produced.

Researchers have found that inhibition of acid secretion by Tagamet, a popular acid stopping drug, resulted in a significant reduction of iron. At the same time, studies have shown that adding acid has improved iron absorption in patients with achlorydia (no stomach acid production).

B12

Vitamin B12 (cobalamin) is needed for normal nerve activity and brain function. B12 enters the body bound to animal-derived proteins. In order for use to absorb it, the vitamin molecules must first be separated from these proteins with the help of – you guessed it – stomach acid.

If stomach acid is low, B12 can’t be separated from its carrier proteins and thus won’t be absorbed. In one study of 359 people aged 69-79 years with serious atrophic gastritis, a disease characterized by low stomach acid, more than 50 percent had low vitamin B12 levels.

A number of studies have examined the negative effect of PPI therapy on B12 absorption. In a study on healthy subjects treated with 20 mg and 40 mg of Prilosec per day for two weeks, B12 absorption was reduced by 72% and 88% respectively.

Folate

Among other things, folate (folic acid) is vital for keeping the cardiovascular system healthy and for preventing certain birth defects. Low stomach acid levels can interfere with folate absorption by raising the pH in the small intestine. At the same time, when folate is given to achlorydric patients (with no stomach acid) along with an HCL supplement, absorption of the vitamin increases by 54 percent.

Both Tagamet and Zantac reduced folate absorption in another study, though the reduction in the Zantac group was not statistically significant. The overall reduction of folate absorption was sixteen percent. This modest reduction is probably not enough to harm a healthy person consuming adequate levels of folate, but it may cause problems in those with folate deficiency (relatively common) or other health problems.

Calcium

Calcium makes our bones and teeth strong and is responsible for hundreds, if not thousands, of other functions in our body. The importance of stomach acid in the absorption of calcium has been known since the 1960s, when one group of researchers noted that some ulcer patients were barely absorbing any calcium at all (just 2 percent). When they investigated they found that these subjects had a high gastric pH (6.5) and very little stomach acid. However, when the researchers gave them HCL supplements, lowering the pH to 1, calcium absorption rose five-fold.

Zinc

Zinc takes part in several metabolic processes related to keeping cell membranes stable, forming new bone, immune defense, night vision, and tissue growth. In one controlled trial, Tagamet treatment reduced zinc absorption by about 50 percent. Another study found that Pepcid, which raises intragastric pH to over 5, had the same effect.

Although there is little systemic research on the absorption of other nutrients, there is good reason to believe that low acid levels may also effect levels of vitamin A, vitamin E, thiamine (vitamin B1), riboflavin (vitamin B2), and niacin (vitamin B3). Theoretically, the absorption of any nutrient that is bound to protein will be inhibited (PDF).

In Part B of this article I will explain how acid stopping drugs decrease our resistance to infection and increase our risk of stomach cancer and other diseases.