# How can dietary fiber be worth anything if it's not long? **URL:** \ **Category:** Factual Questions\ **Created:** [April 7, 2005, 5:59pm UTC](https://boards.straightdope.com/t/how-can-dietary-fiber-be-worth-anything-if-its-not-long/298263 "2005-04-07T17:59:45Z")\ **Posts on this page:** 12\ **Page:** 1
**Author:** ![According\_to\_Pliny](https://avatars.discourse-cdn.com/v4/letter/a/8e7dd6/32.png) [@According\_to\_Pliny](https://boards.straightdope.com/u/According_to_Pliny)\ **Post date:** [April 7, 2005, 5:59pm UTC](https://boards.straightdope.com/t/how-can-dietary-fiber-be-worth-anything-if-its-not-long/298263/1 "2005-04-07T17:59:45Z")
I understand how fiber can be good for your gut. Seems obvious that if you eat celery the strings won’t get fully digested, but will reach the intestines and swab it down, like cleaning a hotdog casing with a q-tip. Since polyps and cancers are known to start in buildup in folds and pockets, such cleaning would be healthful. But some fiber is sold that’s clear, and some is sold as a powder. To my mind that misses the primary definition of a fiber, that it’s long and stringy. What gives? ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [April 7, 2005, 6:13pm UTC](https://boards.straightdope.com/t/how-can-dietary-fiber-be-worth-anything-if-its-not-long/298263/2 "2005-04-07T18:13:54Z")
I think the problem lies in your definition of how fiber works. It doesn’t physically swab anything. A substance that did that would be terribly damaging to the extremely delicate insides of the intestines. There are two ways that the digestive tract can have a problem: too much water or too little water. Fiber can control both. The fiber particles absorb water to remove it from the intestines. This helps to soften stool and prevent hard, sharp stools from the tearing the rectum and anus. Fiber’s absorbency also brings water from the liquids in the food to the stool to bulk it out and help form regular stools. Here’s a quote from the [Metamucil](http://www.metamucil.com/learn/index.shtml) site. > [@](#): > > Dietary fiber is an important part of our diet. It adds bulk to keep other foods moving through the digestive system, and it holds water which, in turn, softens the stool for easy elimination. Dietary fiber describes the part of the plant that can’t be digested. It can be divided into two types, which are essential to proper bowel function: > > 1. Soluble fiber forms a gel-like material in water. It helps restore regularity. Good sources include oats, beans, peas, many types of fruit, and psyllium. > > 2. Insoluble fiber does not dissolve in water and moves through your digestive system quickly and largely intact. It helps keep you regular by bulking up the stool. Good sources include wheat bran, whole-grain cereals and breads, and many vegetables. The secret to getting enough fiber is to eat a well-balanced diet that includes a variety of high-fiber foods. ---
**Author:** ![Excalibre](https://avatars.discourse-cdn.com/v4/letter/e/898d66/32.png) [@Excalibre](https://boards.straightdope.com/u/Excalibre)\ **Post date:** [April 7, 2005, 11:06pm UTC](https://boards.straightdope.com/t/how-can-dietary-fiber-be-worth-anything-if-its-not-long/298263/3 "2005-04-07T23:06:09Z")
> [@Exapno Mapcase](#): > > I think the problem lies in your definition of how fiber works. It doesn’t physically swab anything. Really? What you say sounds very reasonable. But I’ve always been under the impression that that is how fiber works - not necessarily “scrubbing” you out, but helping to clean things. Is it just that it helps maintain stool softness and regularity? Is that the only reason it prevents colon cancer? ---
**Author:** ![cher3](https://avatars.discourse-cdn.com/v4/letter/c/da6949/32.png) [@cher3](https://boards.straightdope.com/u/cher3)\ **Post date:** [April 7, 2005, 11:13pm UTC](https://boards.straightdope.com/t/how-can-dietary-fiber-be-worth-anything-if-its-not-long/298263/4 "2005-04-07T23:13:55Z")
It may not be much help at all in preventing colon cancer: [http://www.hsph.harvard.edu/nutritionsource/fiber.html](http://www.hsph.harvard.edu/nutritionsource/fiber.html) I think the original theory, though, was that it help promote more regular elimination of waste, and the idea was that the less time stuff hangs around in your bowels, the better (within reason.) ---
**Author:** ![spingears](https://avatars.discourse-cdn.com/v4/letter/s/ebca7d/32.png) [@spingears](https://boards.straightdope.com/u/spingears)\ **Post date:** [April 8, 2005, 1:30am UTC](https://boards.straightdope.com/t/how-can-dietary-fiber-be-worth-anything-if-its-not-long/298263/5 "2005-04-08T01:30:04Z")
> [@According to Pliny](#): > > I understand how fiber can be good for your gut. Seems obvious that if you eat celery the strings won’t get fully digested, but will reach the intestines and swab it down, like cleaning a hotdog casing with a q-tip. Since polyps and cancers are known to start in buildup in folds and pockets, such cleaning would be healthful. > But some fiber is sold that’s clear, and some is sold as a powder. > To my mind that misses the primary definition of a fiber, that it’s long and stringy. > What gives? Dietary fiber is not fibrous. It is a different animal (substance, or something.) ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [April 8, 2005, 1:38am UTC](https://boards.straightdope.com/t/how-can-dietary-fiber-be-worth-anything-if-its-not-long/298263/6 "2005-04-08T01:38:09Z")
> [@Excalibre](#): > > Really? > > What you say sounds very reasonable. But I’ve always been under the impression that that is how fiber works - not necessarily “scrubbing” you out, but helping to clean things. Is it just that it helps maintain stool softness and regularity? Is that the only reason it prevents colon cancer? I’ve been involved in food research for over twenty years, and if I’ve learned anything over that time it’s this: people will believe anything at all about food, provided it’s not true. Mostly because the truth is so much more boring. Here’s a nice summary from _The Bowel Book_, by David Ehrlich with George Wolf; > [@](#): > > Persons taking adequate quantities of natural fiber have bulkier stools, more rapid transit of the stools through the tract, and lower intracolonic pressures. The lowered pressures in turn decrease the possibility of both irritable colon and diverticular disease. The shorter transit time and more frequent bowel movement reduce the exposure time to bile acids or other carcinogenic material. Further, because of the greater bulk of the bowel contents, harmful materials may be diluted in some way and rendered less dangerous as they pass through the colon. Unfortunately, the book was written when they still thought that fiber was a preventive of colon cancer. That linkage is doubtful. I suppose you could stretch this in some way to say that fiber cleans things out, but that’s a really bad misunderstanding of what happens, which basically is all about water. Water cleans very nicely, thank you, which is why **cher3’s** cite says: > [@](#): > > Wondering how much water or other beverages you should drink a day? The Institute of Medicine’s Food and Nutrition Board gives the following general recommendations for water consumption: Women generally need to consume 91 ounces of water each day from beverages and foods, while men generally need to consume 125 ounces each day. People typically obtain about 80 percent of their water from beverages (including beverages that contain caffeine) and 20 percent of their water from foods. So for women, that translates into drinking 9 8-oz. glasses of water or other beverages each day and obtaining another 18 ounces of water from foods; for men, that translates into drinking roughly 12 8-oz. glasses of water or other beverages each day, and obtaining another 25 ounces of water from foods. That’s also why taking powdered fiber in a glass of water is better than a tablet. Most people won’t drink the full glass of water with the tablet, but just enough to swallow the pill. The water is necessary to work with the fiber. My motto is: never get medical advice from a newspaper. They jump on every medical journal article as if nothing ever came out before and nothing will ever come out again and so whatever it says is the final word and can be applied to your life, even if it was a study of 7 pregnant vegans with elephantiasis. Anything you’ve ever “heard” is wrong. 🙂 ---
**Author:** ![Qadgop\_the\_Mercotan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/qadgop_the_mercotan/32/83_2.png) [@Qadgop\_the\_Mercotan](https://boards.straightdope.com/u/Qadgop_the_Mercotan)\ **Post date:** [April 8, 2005, 1:43am UTC](https://boards.straightdope.com/t/how-can-dietary-fiber-be-worth-anything-if-its-not-long/298263/7 "2005-04-08T01:43:16Z")
**Exapno** knows of what he speaks! Wise dopers will heed **Exapno** when he expounds on fiber! I’ve advocated more fiber for my patients for decades now. Fiber is like a good aerobic workout for the colon. I eat about 60 grams of fiber a day. My colon is my fittest organ!! ---
**Author:** ![Jenaroph](https://avatars.discourse-cdn.com/v4/letter/j/e8c25b/32.png) [@Jenaroph](https://boards.straightdope.com/u/Jenaroph)\ **Post date:** [April 8, 2005, 2:46am UTC](https://boards.straightdope.com/t/how-can-dietary-fiber-be-worth-anything-if-its-not-long/298263/8 "2005-04-08T02:46:56Z")
> [@Qadgop the Mercotan](#): > > I’ve advocated more fiber for my patients for decades now. Fiber is like a good aerobic workout for the colon. I eat about 60 grams of fiber a day. My colon is my fittest organ!! Yeah, but do you crap bigger than Jack Palance? _I’m terribly sorry. I have nothing else to add here._ ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [April 8, 2005, 3:14am UTC](https://boards.straightdope.com/t/how-can-dietary-fiber-be-worth-anything-if-its-not-long/298263/9 "2005-04-08T03:14:32Z")
> [@Qadgop the Mercotan](#): > > **Exapno** knows of what he speaks! Wise dopers will heed **Exapno** when he expounds on fiber! One of these would have been a great sig line. Both of them together though… Maybe I should save this for when we can get custom titles. Fiber Expounder. Has a ring to it. 🙂 ---
**Author:** ![OxyMoron](https://avatars.discourse-cdn.com/v4/letter/o/e9a140/32.png) [@OxyMoron](https://boards.straightdope.com/u/OxyMoron)\ **Post date:** [April 8, 2005, 1:54pm UTC](https://boards.straightdope.com/t/how-can-dietary-fiber-be-worth-anything-if-its-not-long/298263/10 "2005-04-08T13:54:43Z")
But, **Exapno** , what about the suggestion that these water recommendations are a load of, um, [balderdash](http://www.snopes.com/toxins/water.htm)? ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [April 8, 2005, 2:30pm UTC](https://boards.straightdope.com/t/how-can-dietary-fiber-be-worth-anything-if-its-not-long/298263/11 "2005-04-08T14:30:16Z")
I was concentrating on the part of the quote that stated that you need to get your fluids from “beverages and food,” which is quite correct. The notion that you need to keep a tank of bottled water on your hip is a myth. We are not generally dehydrated. As Snopes points out, though, we do drink enormous amounts of liquids and probably need them. > [@](#): > > The consensus seems to be that the average person loses ten cups (where one cup = eight ounces) of fluid per day but also takes in four cups of water from food, leaving a need to drink only six glasses to make up the difference, a bit short of the recommended eight to ten glasses per day. But according to the above-cited article, medical experts don’t agree that even that much water is necessary: But liquids are a good thing, especially for those who have bowel troubles. I have no problems recommending lots of fluid intake. It doesn’t have to be in the form of water. But. Huge amounts of caffeinated sugar water have other problems, so I’d still be leery of them even if they don’t dehydrate you. ---
**Author:** ![LorieSmurf](https://avatars.discourse-cdn.com/v4/letter/l/a587f6/32.png) [@LorieSmurf](https://boards.straightdope.com/u/LorieSmurf)\ **Post date:** [April 8, 2005, 2:54pm UTC](https://boards.straightdope.com/t/how-can-dietary-fiber-be-worth-anything-if-its-not-long/298263/12 "2005-04-08T14:54:53Z")
[QUOTE=Qadgop the Mercotan I’ve advocated more fiber for my patients for decades now. Fiber is like a good aerobic workout for the colon. I eat about 60 grams of fiber a day. My colon is my fittest organ!![/QUOTE] \ "My stools are GIGANTIC! With no more odor than a hot biscuit! \