Q: Food often sits heavy in my stomach. Should I be taking a daily digestive enzyme supplement?
A: Digestive enzyme supplements promise to fix everything from bloating and flatulence to heartburn and gut health. Some of them are clearly beneficial, in certain situations. But enzyme supplements are too often used in situations where there is little evidence that they do any good.
Naturally occurring digestive enzymes help break down food so we can soak up nutrients. Your mouth, stomach, and small intestine make some digestive enzymes. However, the majority come from your pancreas, which floods the small intestine (when food arrives there) with enzymes such as:
--lipase, which breaks down fats
--amylase, which breaks down carbohydrates
--proteases and peptidases, which break down proteins.
Once nutrients are broken into small enough molecules, they are absorbed through the wall of the small intestine into the blood and then delivered throughout the body.
Sometimes the body doesn't make enough digestive enzymes. This can slow the digestion process and lead to uncomfortable symptoms. For example, if you don't make enough of the enzyme lactase, you'll have a hard time digesting lactose -- the sugar in milk and milk-based products.
If you don't have lactase, the undigested lactose goes to the colon, which leads to more fluid entering the colon and more gas produced by bacteria in the colon. That creates bloating, flatulence, and diarrhea.
For people that can't make enough digestive enzymes because of a health condition such as chronic pancreatitis or cystic fibrosis, doctors prescribe enzyme pills to substitute for the lack of natural enzyme production. People with known deficiencies clearly get a benefit.
Likewise, we know that taking a nonprescription lactase supplement (such as Lactaid or Lactrase) can help people manage lactose intolerance, and taking an alpha-galactosidase supplement (such as Beano or Bean Relief) may reduce gas and bloating if you have a hard time digesting the sugars in beans.
But for other common gut problems, like heartburn or irritable bowel syndrome, there is little evidence that digestive enzymes are helpful.
(Howard LeWine, M.D., is an internist at Brigham and Women's Hospital in Boston and assistant professor at Harvard Medical School. For additional consumer health information, please visit www.health.harvard.edu.)