It took me an embarrassingly long time to get soluble versus insoluble fiber straight. I finally got it. Today's blog post will lay out the differences between the two and hopefully help you keep them straight too.
Soluble fiber is the kind that attracts water and turns into a gel in the digestive tract. This gel pulls water from the GI tract to slow movement and bulk up the stool. Soluble fiber helps prevent constipation and diarrhea. While soluble fiber is bulking up the stool, it also pulls in cholesterol particles from the body and adds them to the stool. When the body passes a bowel movement, it also passes the excess cholesterol. Soluble fiber also helps to keep blood sugar levels stable so that you feel fuller for longer and increases the amount of healthy bacteria in the intestines. Soluble fiber is found in oat bran, whole grains, fruits, and beans.
Bottom line: soluble fiber bulks up the stool and lowers cholesterol.
Insoluble fiber does not attract water and in fact is not absorbed at all. This is the type of fiber that people think of as "roughage". Because insoluble fiber is not absorbed in the GI tract, it keeps the GI tract moving. Insoluble fiber helps with constipation and hemorrhoids. Insoluble fiber is found in seeds and skins of fruit and veggies and stalks.
Bottom line: insoluble fiber keeps things moving.