Better health, that’s the only reason. It does not make you smarter, does not make you lose weight, and doesn’t make you the hit of the party, unless it’s a passing gas party. But, it does have many health benefits. Oh, and it can help you lose weight (i.e. look better) by making you fuller.
Cancer: The fact is I could not find any consistent reliable indication that fiber, by itself, has any beneficial effect on any type of cancer. My personal take on all these studies is this. Just adding plain old fiber as a supplement, as many studies did, DOES NOT provide any benefit in regards to cancer. HOWEVER, the source of fiber, whole fruits and vegetables – not pulpless juice from your juicer to make it go down easier – does provide cancer benefits. But, we don’t know, we don’t know what part of natures bounty is healthy and what isn’t, so eat the whole thing, and lots of it!
Diabetes: Now, here is a real winner. Hands-down fiber has great potential when it comes to diabetes. Both soluble and insoluble fiber helps, but the higher the level of soluble fiber the better.
CardioVascular Disease: YES, fiber plays a major role in preventing this killer disease.
High Blood Pressure: Again, fiber does help, but not as significantly as I would like. But, there are other nutritional changes besides fiber that do make a big difference.
Weight loss: Weight loss, now were talking. This is what we all want, and more than likely the entire reason you are reading this. So what’s the verdict? Will fiber help me lose weight?
Constipation: This is a big YES, and consuming more fiber is even more important in adolescents and teens. Here’s my take as a frontline family physician.
Irritable Bowel Disease: Mixed reviews, but there does appear to be some benefit.
Stool incontinence: YES
MISC: A low-fat, high-fiber diet (not supplementation) has been found beneficial in other conditions such as
Porphyria cutanea tarda, lung disease (COPD), reduced dental caries, and lower testosterone levels in men.
Colon Cancer: I am here to dispense facts and advice based upon solid research. Yes, research changes and today’s fact can become tomorrow’s fallacy. But I will tell you when the facts have changed. When I went to school and during most of my career I was taught that fiber will prevent certain cancers including colon cancer. Even major, very reputable organizations such as the American Dietetic Association (which I highly support and respect) have a hard time abandoning this position. Here is what they say:
“High-fiber foods help move waste through your digestive tract faster, so harmful substances don't have much contact with the lining of the intestine. High-fiber foods are also rich in phytonutrients, which appear to protect against several forms of cancer.”
They don’t say fiber prevents cancer, but they really don’t say it doesn’t. The American Cancer Association (ACA) said this on 5/7/2003:
Two new studies suggest fiber does have a role in protecting against colon cancer. The findings are intriguing because several previous large, well-conducted studies have found no such link.
But, the ACA go on to temper this position:
An American Cancer Society expert notes that it’s difficult to pinpoint exactly which element gives the most benefit.
“Fiber is correlated with other healthy components of a plant-based diet and it’s hard to disentangle what the responsible factor or factors might be because they’re so closely tied,” said Marji McCullough, a nutritional epidemiologist with the ACS.
For instance, many high-fiber foods also contain folate and other vitamins, which may be protective. And many people who consume a high-fiber diet are also more likely to eat less red meat, drink less alcohol, smoke less, and get regular exercise – all healthy behaviors that can reduce cancer risk.
Finally, the American medical Association, on December 14, 2005, reported this:
Smith-Warner at the Harvard School of Public Health in Boston and colleagues analyzed data from 13 studies with follow-up times of 6 to 20 years. More than 8,000 cases of colon cancer were included in the analysis.
After accounting for folic acid intake and other dietary factors, consumption of diets high in fiber did not offer significant protection against colon cancer.
Breast cancer: Women with higher fiber diets have better control of insulin, lower estradiol, and changes in sex hormone-binding globulin. But, none of the studies I found specifically relate fiber, without the associated fruits and vegetables, as having any benefit in reducing breast cancer.
Prostate cancer: Nope.
Gastric cancer: Nothing clear.
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I found no less than 13 major articles in agreement (none that disagreed) that fiber will help or eliminate diabetes, both adult (Type 2) and juvenile (Type 1). One study involved 91,249 women showing cereal fiber improved diabetic risk. Another study showed that increasing your fiber from 9 grams a day (1.7 grams soluble) to 26 grams a day (3.5 soluble) reduced glucose by 12%.
The diabetic reducing effects of fiber is dose dependant. The American Journal of Clinical Nutrition reported a study of over 4,000 men and women followed for 10 years that found a 35% reduction in the incidence of type 2 diabetes from persons with the highest compared to the lowest levels of fiber intake. Another study from Nutrition Revue in 2001 showed continued benefit by increasing fiber from 25 grams/day to 50 grams/day (50% soluble). Even the New England Journal of Medicine stated that increasing fiber above the levels recommended by the American Diabetic Association helped lower glucose.
What's nice about fiber is that it not only reduces your blood sugar, it also helps prevent side effects of too low a sugar! Diabetes Care, in 2000, reported that a fiber-rich diet reduced the number of hypoglycemic attacks in type 1 (insulin) diabetic patients.
The American Diabetes Association, in 2004, stated “people should eat 25-50 grams of fiber every day. High-fiber foods include oats and barley; whole-grain breads, cereals, and pastas; brown rice, dry beans, peas, and lentils; nuts, bruits, and vegetables." The research is clear. Fiber is extremely important in diabetes.
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CARDIO VASCULAR DISEASE (CVD)
When I was in school and even as recently as 5-10 years ago fiber was not considered to be very important in heart disease; cholesterol was the dominant culprit. Then, in 1999, The Scottish Heart Healthy Study suggested that dietary fiber was more important than antioxidants, vitamins C and E, and beta carotene in improving survival rates and lowering CVD cases. Everybody jumped on the bandwagon and in 2000 and 2001 more studies were released showing the undeniable benefit from fiber, particularly soluble fiber in protecting the heart.
In 2002 the US Food and Drug Administration (FDA) actually approved a claim of health benefits for 2 soluble fibers. Beta-glucan (0.75 g/serving) and psyllium (1.78 g/serving) on the assumption that 4 servings/day would reduce cardiovascular disease risk. The actual level of cholesterol reduction provided by this amount equaled a 4% reduction in risk based on Framingham risk predictions.
In April 2003 the Journal of American Medical Association (JAMA) reported that even in elderly men and women over age 65 fiber still has a cardio-protective function. Following 3,588 people for 8.6 years, cereal fiber was shown to reduce cardiovascular disease risk by 21%. Dark breads such as wheat, rye, or pumpernickel were associated with an even lower risk of 24%.
How does this work?
C-reactive protein (CRP) is an inflammatory marker in the blood. Just like cholesterol we can use it as a potential predictor of future CVD events. The higher it is, the more likely you will have a problem. Every 1.0 mg/liter increase in CRP is associated with a 25% increase in risk of CVD. Fiber has been shown to reduce CRP in several studies.
Cholesterol has been shown to be effectively reduced with fiber. One study compared a diet consisting of plant sterols (1.0 g/1000 kcal), soy-protein foods (21.4 g/1000 kcal), almonds (14 g/1000 kcal), and viscous fibers from oats, barley, psyllium, and the vegetables okra and eggplant (10 g/1000 kcal) to a popular cholesterol lowering medication, Lovastatin 20 mg. Guess who won? Another study with a very high fiber diet, 55 gram/1000 Kcal) provided from vegetable, fruit and nuts reduced LDL cholesterol by 33%. Yet another study looked at a high-fiber diet (48 g/day) compared to a low-fiber diet (27 gram/day) and found a definite reduction of cholesterol, triglycerides and LDL with fiber.
These benefits in CRP, cholesterol, LDL along with the benefits on hypertension and diabetes are powerful reasons why it makes sense that fiber will help prevent your next or first heart attack or stroke.
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HIGH BLOOD PRESSURE
While not real strong, there is a definite relationship between fiber and blood pressure. At 8-11.5 g/d systolic pressure will drop an average of 2mm and diastolic by 1.2mm. BUT, another study that combined an increase of dietary protein from 12.5% of calories to 25%, by adding, YUK, soy, together with fiber at 15 g/d plus an additional 12 gram of psyllium did show a significant change. People already being treated for hypertension showed an additional drop of 6mm of blood pressure.
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I promised you in the beginning that I WILL NOT INTENTIONALLY MISLEAD YOU AND I WILL NOT KNOWINGLY PROMOTE ANY FADS OR MYTHS. There are numerous studies present on the subject of weight loss and fiber and just about anything else you can think of.
Weight maintenance - A high-fiber diet is absolutely essential for weight-loss maintenance. That means once you have lost the weight, you need to maintain a calorie level that maintains your new weight (not your old way of eating) with high-fiber foods. If you go to low-fiber, high-calorie foods you will regain your weight. Even in the general public not trying to maintain a weight loss the studies show that a naturally selected high-fiber lifestyle reduced the amount of weight gain in men during an 8-year study.
Weight loss – No go. I cannot find enough studies that consistently show weight loss from a high-fiber diet. What I mean by this is – you cannot continue with your fast food, chocolate bars, salads drowned in dressing, and potato chip snacking and expect to loss weight just by adding more fiber to this ridiculous meal plan you call a diet. You are going to have to make changes to your lifestyle if you want to lose weight!
Before you give up on fiber - there are positive benefits of fiber for weight loss. First, the body tells you when it is full by the volume of food you consume, not the weight of the food. A pound of lettuce is much more filling than a pound of grease. By consuming high-fiber foods you are filling yourself up with low-calorie, nutrient-rich foods, curbing your appetite and allowing you to eat less. Several studies reported the observation that the high-fiber groups felt fuller, more satisfied, and fewer subjects dropped out of the study compared to subjects on low-fiber diets.
In conclusion, just adding fiber will not make you lose weight, but it is critical to maintain weight loss AND to help keep you on track losing weight. Eat your fiber.
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Every week I see kids complaining of vague stomach pain. When I tell the parents it is constipation they all insist that junior eats right and goes to the bathroom regularly. So, I obtain an x-ray and low-and-behold what does it show – severe constipation. Junior cleans him/herselves out with a little MOM (milk-of-magnesia) and wham, they are good to go; until the next trip to Mc Donald’s.
The research agrees. Using conservative levels of fiber in children reduces constipation by at least 68%. The American Health Foundation determined a safe level of fiber for children as their age plus 5 g/day. According to the US Department of Agriculture 55% to 90% of children are not meeting this recommended level.
I guarantee you that when you eat adequate fiber you can say bye-bye to constipation.
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IRRITABLE BOWEL DISEASE
Two of three studies reported that patients on a moderate fiber diet had improved feelings of well-being, less abdominal pain and less bloating. The third study reported no improvement; but at least it did no harm. So my recommendation is that you should use a high-fiber diet even with irritable bowel disease.
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A few different studies have reported improvement in fecal incontinence with supplementation with fiber.
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Low-fiber intake is thought to be the cause of 70% of cases of appendicitis in children
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