Enzyme Myth: All Enzymes are Destroyed by Stomach Acid

This myth states that taking enzyme supplements is a waste of time and money because the enzymes, being proteins, are denatured (destroyed) by the acid in the stomach.

I once believed this statement because it was taught to me in medical school. Not till I was challenged to verify the statement did I find that what I was taught was not completely true.  

The majority of enzymes, including pancreatic enzymes, are not stable under acid conditions and so are not effective taken orally. There are two exceptions: enzymes that have been enteric-coated (that is, treated with a substance that prevents contact with stomach acid) and PLANT-BASED ENZYMES.  

The problem with enteric-coated enzymes is that the coating prevents enzymes from working in the stomach. Only in the neutral pH of the small intestine will they finally function. Plant-based enzymes, which comprise the bulk of enzyme supplements, are derived from plant organisms that secrete acid-stable enzymes. These enzymes have been purified and characterized so their pH optimum (acidity/alkalinity at which they work best) is well known and easily determined.  

The majority of these enzymes can work in a pH range of 2 to 9 with no loss of activity. This is not an opinion. The enzymes can be assayed, or analyzed, under lab conditions at different pH. This is easily verified by enzyme manufacturers.

The ability of enzymes to work in the stomach provides the means by which protease enzymes degrade gluten, casein, soy and other food proteins. The peptides that many find intolerable are degraded or not produced. The stomach actually becomes a "safe house" when someone who does not tolerate dairy ingests these foods. No peptide or protein absorption occurs in the stomach, so you have a couple of hours to use the enzymes to break down the proteins before they move into the small intestine where the bulk of protein/peptide absorption will occur.

I was humbled years ago when I had to come back and admit to my "challenger" that I was misinformed about plant enzymes and their acid stability. It taught me not to take a teacher's word, but to verify the subject matter for myself. I highly recommend others do the same.

- Devin Houston