Your local drugstore or health food store no doubt has a wide variety of digestive enzyme supplements available for purchase. You may have heard that supplementing with digestive enzymes improves your nutrient uptake, helps prevent various diseases and increases general health. There is no scientific evidence to support this notion, however.
Digestive Enzymes
The cells that line your digestive tract produce and secrete digestive enzymes, as does your pancreas. These enzymes break down the large nutrient molecules in the food you eat into smaller molecules that your small intestine can absorb into your bloodstream. The cells then take up nutrients from the blood. Proper absorption of your food depends upon the production of a variety of digestive enzymes, each of which digests only one type of nutrient.
Enzyme Deficiencies
Though it might be tempting to blame your health or conditions on digestive enzyme deficiencies, the reality is that such deficiencies are in general very rare. For instance, sucrase-isomaltase deficiency -- the insufficient production of the enzyme that digests table sugar -- is one of the more common digestive enzyme deficiencies, and is present in only 0.02% of those of European descent, according to the National Institutes of Health.
Problems With Supplementing
Deficiencies aside, there's a major barrier to supplementing with digestive enzymes. Enzymes can't withstand temperatures or acidities in which they don't generally operate. For instance, enzymes of the small intestine operate at near-neutral acidity. Therefore, they can't withstand the very acidic environment inside the stomach. However, to supplement with intestinal enzymes, you must first swallow them -- this subjects them to the stomach interior, which destroys them. Since most digestive enzymes are intestinal, it's quite difficult to supplement from the perspective of bioavailability.
Lactose Intolerance
The one exception to the general rule that you can't -- and don't need to -- supplement with digestive enzymes is the case of lactase for lactose intolerance. If you don't produce sufficient lactase -- the enzyme that helps you digest milk sugar -- you can use supplements provided you take them at the same time that you consume dairy. However, even lactose intolerance isn't as common as you might think; most individuals who think they're lactose intolerant aren't, explained Dr. John Saltzman and colleagues in a 1999 article in the "American Journal of Clinical Nutrition."
References
- "Human Physiology"; Lauralee Sherwood, Ph.D.; 2004
- "Biochemistry"; Reginald Garrett, Ph.D. and Charles Grisham, Ph.D.; 2007
- Genetics Home Reference: Sucrase Deficiency
- "American Journal of Clinical Nutrition"; A Randomized Trial of Lactobacillus acidophilus BG2FO4 to Treat Lactose Intolerance; J. Saltzman et al.; January 1999
