When a meal contains fiber, this process is much slower, eliminating blood sugar spikes and increasing feelings of fullness for several hours after eating.” A sense of fullness is only one of many benefits of fiber
Fiber is found in foods that come from plants (ie. fruits, vegetables, and grains. The body cannot digest fiber, but it plays an important role in one’s overall health. There are two types of fiber, insoluble and soluble. Insoluble fiber holds water like a sponge, and does not dissolve in water. It keeps food soft s it moves through the intestines so that waste products can be easily eliminated. Soluble fiber dissolves in water, turning the food in the intestines into a gel from which nutrients can be absorbed at a slow, steady rate. Both types of fiber are a part of a healthy diet and there are numerous health benefits of fiber.
Dietary fiber intake provides many health benefits of fiber . A generous intake of dietary fiber reduces risk for developing the following diseases: coronary heart disease, stroke, hypertension, diabetes, obesity, and certain gastrointestinal disorders. Furthermore, increased consumption of dietary fiber improves serum lipid concentrations, lowers blood pressure, improves blood glucose control in diabetes, promotes regularity, aids in weight loss, and appears to improve immune function.
Unfortunately, most persons in the United States consume less than half of the recommended levels of dietary fiber daily. This results from suboptimal intake of whole-grain foods, vegetables, fruits, legumes, and nuts. Dietary fiber supplements have the potential to play an adjunctive role in offering the health benefits provided by high-fiber foods.
Fiber is a type of carbohydrate that the body can’t digest. Though most carbohydrates are broken down into sugar molecules, fiber cannot be broken down into sugar molecules, and instead it passes through the body undigested. Fiber helps regulate the body’s use of sugars, helping to keep hunger and blood sugar in check.
Eating more fiber delivers a slew of health benefits. Here are health benefits of fiber to encourage you get your fill.
What Is Fiber?
Put simply, dietary fiber is a non-digestible carbohydrate found in foods.
It’s split into two broad categories based on its water solubility:
- Soluble fiber: Dissolves in water and can be metabolized by the “good” bacteria in the gut.
- Insoluble fiber: Does not dissolve in water.
Perhaps a more helpful way to categorize fiber is fermentable versus non-fermentable, which refers to whether friendly gut bacteria can use it or not.
It’s important to keep in mind that there are many different types of fiber. Some of them have important health benefits, while others are mostly useless.
There is also a lot of overlap between soluble and insoluble fibers. Some insoluble fibers can be digested by the good bacteria in the intestine, and most foods contain both soluble and insoluble fibers.
Health authorities recommend that men and women eat 38 and 25 grams of fiber per day, respectively.
Soluble and Insoluble Fiber: What’s the Difference Between the Two?
There are two types of fiber: soluble and insoluble. While both are important, the two function differently in the body. Here’s how:
Soluble Fiber
Soluble fiber is a type of fiber that attracts water and forms a gel. This gel causes a slowing of the digestion process, which can be beneficial for weight loss. Foods high in soluble fiber include oats, legumes, edible plant skins, and nuts.
Insoluble Fiber
Insoluble fiber is the type of fiber that, you guessed it, repels water. You can find insoluble fiber in foods such as veggies, fruits, nuts and seeds, wheat bran, and whole-grain foods like whole-wheat pasta and brown rice. Its primary benefit is to provide bulk to stool and aid in the movement through the digestive tract.
Most diets have a combination of soluble and insoluble fiber, with 75 percent coming from insoluble fiber and 25 percent coming from soluble fiber
How Much Fiber Do You Need Per Day?
Most of us fall far short of the ideal, consuming only about nine to 11 grams per day. Dietitians recommend 35 grams (for women) to 38 grams (for men) of fiber.
The new FDA nutrition label recommends 28 grams of fiber per day for a 2,000 calorie diet.
Understanding The Many Benefits of Fiber for The Body
Fiber is found in foods that come from plants (ie. fruits, vegetables, and grains. The body cannot digest fiber, but it plays an important role in one’s overall health. There are two types of fiber, insoluble and soluble. Insoluble fiber holds water like a sponge, and does not dissolve in water. It keeps food soft s it moves through the intestines so that waste products can be easily eliminated. Soluble fiber dissolves in water, turning the food in the intestines into a gel from which nutrients can be absorbed at a slow, steady rate. Both types of fiber are a part of a healthy diet and there are numerous health benefits of fiber.
You’ll Lose Weight
Even if increasing your fiber intake is the only dietary change you make, you’ll shed pounds. Dieters who were told to get at least 30 grams of fiber a day, but given no other dietary parameters, lost a significant amount of weight, found a recent study in the Annals of Internal Medicine. In fact, they lost nearly as much as a group put on a much more complex diet that required limiting calories, fat, sugar and salt and upping fruit, veggie and whole-grain consumption.
Fiber-rich foods not only fill you up faster and keep you satisfied longer, they also prevent your body from absorbing some of the calories in the foods you eat. “Fiber binds with fat and sugar molecules as they travel through your digestive tract, which reduces the number of calories you actually get,” explains Tanya Zuckerbrot, R.D., author of The F-Factor Diet. Another study found that people who doubled their fiber intake to the recommended amount knocked off between 90 and 130 calories from their daily intake-that’s equal to a 9- to 13-pound weight loss over the course of a year.
Learn more about fiber and weight-loss and why you should be eating more of these seven high-fiber foods that can help you lose weight.
Fiber Feeds “Good” Gut Bacteria
The bacteria that live in the human body outnumber the body’s cells 10 to 1.
Bacteria live on the skin, in the mouth and in the nose, but the great majority live in the gut, primarily the large intestine.
About 500 different species of bacteria live in the intestine, totaling about 100 trillion cells. These gut bacteria are also known as the gut flora.
This is not a bad thing. In fact, there is a mutually beneficial relationship between you and some of the bacteria that live in your digestive system.
You provide food, shelter and a safe habitat for the bacteria. In return, they take care of some things that the human body cannot do on its own.
Of the many different kinds of bacteria, some are crucial for various aspects of your health, including weight, blood sugar control, immune function and even brain function.
You may wonder what this has to do with fiber. Just like any other organism, bacteria need to eat to get energy to survive and function.
The problem is that most carbs, proteins and fats are absorbed into the bloodstream before they make it to the large intestine, leaving little for the gut flora.
This is where fiber comes in. Human cells don’t have the enzymes to digest fiber, so it reaches the large intestine relatively unchanged.
However, intestinal bacteria do have the enzymes to digest many of these fibers.
This is the most important reason that (some) dietary fibers are important for health. They feed the “good” bacteria in the intestine, functioning as prebiotics .
In this way, they promote the growth of “good” gut bacteria, which can have various positive effects on health .
The friendly bacteria produce nutrients for the body, including short-chain fatty acids like acetate, propionate and butyrate, of which butyrate appears to be the most important.
These short-chain fatty acids can feed the cells in the colon, leading to reduced gut inflammation and improvements in digestive disorders like irritable bowel syndrome, Crohn’s disease and ulcerative colitis .
When the bacteria ferment the fiber, they also produce gases. This is the reason high-fiber diets can cause flatulence and stomach discomfort in some people. These side effects usually go away with time as your body adjusts.
Heart Disease
High intake of dietary fiber has been linked to a lower risk of heart disease in a number of large studies that followed people for many years. (16) In a Harvard study of over 40,000 male health professionals, researchers found that a high total dietary fiber intake was linked to a 40 percent lower risk of coronary heart disease. (17) A related Harvard study of female nurses produced quite similar findings. (18)
Higher fiber intake has also been linked to a lower risk of metabolic syndrome, a combination of factors that increases the risk of developing heart disease and diabetes. These factors include high blood pressure, high insulin levels, excess weight (especially around the abdomen), high levels of triglycerides, and low levels of HDL (good) cholesterol. Several studies suggest that higher intake of fiber may offer protective benefits from this syndrome.
Digestive Disorders
Fiber is like nature’s scrub brush, keeping your body’s pipes clear and reducing carcinogenic activity.
One benefit of getting enough fiber in your diet is reducing the risk of diverticulitis, a condition in which pouches formed in the colon become infected. Fiber helps keep food clear from the pouches and moving through the digestive tract. Aim to take in 25 to 40 g of fiber per day to reduce your risk of diverticulitis.
There’s an anti-cancer benefit to fiber, too: Both soluble and insoluble fiber can also play a role in warding off colon cancer.
Fiber Is Important for Gut Health
The trillions of naturally-occuring bacteria in your gut feed on fiber as it’s digested. In fact, complex carbohydrates like the ones found in whole grains, beans, and legumes are some of your gut bacteria’s favorite things to feast on.
Gut bacteria, which collectively make up the “gut microbiome,” are important because they extract vitamins and minerals your stomach acid leaves behind. Your colon then absorbs nutritional building blocks such as
Vitamin K, B12, thiamin, and folate and puts them to work in your bloodstream.
Researchers are just beginning to understand all that these hungry bacteria do. But a 2011 paper published in Surgical Clinics of North America found the gut microbiome supports metabolism, contributes to your immune system, regulates energy levels, and much more.
Prebiotic foods are especially beneficial for gut health. These foods, like onions and garlic, contain “fermented fiber.” As the bacteria in your colon break down fermented fiber, gases are produced.
These gases can cause discomfort in the lower tract of your digestive system as they inflate your colon, and lead to bloating. To get the full benefits of fiber without the discomfort, add fiber to your diet slowly, increasing the amount you consume slightly over the course of weeks or months.
Fiber Helps Reduce Your Risk of Colorectal Cancer
People who eat a lot of fiber had a 35% lower risk of colorectal cancer, according to the four-year U.S. Polyp Prevention Trial. Researchers believe that the reduced cancer risk is because fiber moves food more quickly through the digestive system, minimizing cellular exposure to potential carcinogens as it removes waste more efficiently.
Another cancer-fighting benefit linked to fiber consumption is production of a substance called butyrate, created when bacteria in the lower intestine break down fiber. Butyrate protects against growth of tumors of the colon and rectum and also helps tamp down inflammation in the gut, which is associated with a 500 times greater risk of developing colorectal cancer.
Fiber Steadies Your Blood-Sugar Level
Fiber, especially the soluble type, found in psyllium, bran, and legumes slows the absorption of sugar from the intestines. This steadies the blood sugar level and lessens the ups and downs of insulin secretion. So a breakfast and lunch containing moderate amounts of soluble fibers, such as bran, fruit, and oats, can be especially valuable to a child who shows behavior and learning difficulties from blood sugar swings. Keeping insulin levels low and stable also helps the body store less fat, another perk for people trying to control their weight through the benefits of fiber.
Get an All-Natural Detox
Who needs a juice cleanse? Fiber naturally scrubs and promotes the elimination of toxins from your G.I. tract. Explains Zuckerbrot: “Soluble fiber soaks up potentially harmful compounds, such as excess estrogen and unhealthy fats, before they can be absorbed by the body.” And, she adds, because insoluble fiber makes things move along more quickly, it limits the amount of time that chemicals like BPA, mercury and pesticides stay in your system. The faster they go through you, the less chance they have to cause harm. (Don’t miss: Why you should skip the cleanse.)
Some types of soluble fiber-dubbed “prebiotics” and found in asparagus, leeks, soybeans, wheat and oats-have been shown to increase the bioavailability of minerals like calcium in the foods you eat, which may help maintain bone density.
Fiber Can Reduce Cholesterol, but the Effect Isn’t Huge
Viscous, soluble fiber can also reduce your cholesterol levels.
However, the effect isn’t nearly as impressive as you might expect.
A review of 67 controlled studies found that consuming 2–10 grams of soluble fiber per day reduced total cholesterol by only 1.7 mg/dl and LDL cholesterol by 2.2 mg/dl, on average.
But this also depends on the viscosity of the fiber. Some studies have found impressive reductions in cholesterol with increased fiber intake.
Whether this has any meaningful effects in the long term is unknown, although many observational studies show that people who eat more fiber have a lower risk of heart disease.
Diverticular disease
Diverticulitis, an inflammation of the intestine, is one of the most common age-related disorders of the colon in Western society. Among male health professionals in a long-term follow-up study, eating dietary fiber, particularly insoluble fiber, was associated with about a 40 percent lower risk of diverticular disease
Blood Pressure Reduction
Fiber’s wondrous effect on the body is a great example of medical nutrition therapy (MNT), a technique registered dietitian nutritionists (RDN) use on their patients to reduce the need for medication while improving health outcomes.
Here’s how it works: Your body uses bile salts, which are excreted by the gallbladder to break apart the fat content in food. Bile salts are made of cholesterol.
When you eat food with fiber, the fiber binds to the bile salts, preventing them from being recirculated for the next time you eat. As a result, your body must produce more bile salts by taking cholesterol from the liver. This is how soluble fiber reduces blood cholesterol.
Fiber has a preventative role on blood pressure, too, but the reason is more associated with nutrients such as potassium, calcium, and magnesium contained in foods high in fiber.
If you are not convinced to increase your fiber intake yet, know there’s also data emerging on fiber’s ability to impact the immune system, mood, and memory by the promotion of healthy gut bacteria.
Fiber May Reduce Constipation
For some people, consuming fiber can relieve constipation. That’s because fiber adds bulk to your stool, helping it to clear out.
A 2016 medical review published in Alimentary Pharmacology and Therapeutics synthesized the results of seven different randomized controlled trials. They found that 77% of adult participants successfully treated some chronic constipation symptoms by consuming more dietary fiber. However, researchers found that flatulence also increased with a higher fiber intake, which could lead to abdominal discomfort.
If you’re trying to treat constipation, both soluble and insoluble fiber will help. However, be aware fiber can sometimes make constipation worse, especially if you are dehydrated. Make sure that you are drinking plenty of water as you slowly increase your fiber intake.
Read more about the best ways to get rid of constipation.
Fiber Binds Carcinogens
Besides moving carcinogens (toxins that can transform normal cells into cancerous ones) through the bowels faster, fiber binds these substances, lessening their contact time with the intestinal wall. The water and bulk of the stools also dilutes carcinogens, decreasing their potential to do harm. In addition, fiber absorbs bile acids and other potential irritants that may predispose the intestinal lining to cancer. Studies of persons at high risk for colorectal cancer showed that those eating a high fiber diet (primarily wheatbran) had a much lower chance of going on to develop colon cancer than those on a low fiber diet.
While more and more studies confirm the link between high-fiber diets and lowered risk of colon cancer, the effect of fiber on other cancers is less clear. Preliminary studies have shown that high-fiber diets may decrease the risk of stomach and breast cancer. There are several possible explanations for this. Fiber binds estrogen in the intestines, thereby reducing the chance of breast cancer .
Fiber also binds toxins, keeping them away from vulnerable tissues.A recent article in The New England Journal of Medicine received a lot of publicity by reporting on the results of a study in which the eating habits of 88,000 nurses were tracked over sixteen years. The study found that there was no difference in the incidence of colorectal cancer between those who ate a low-fiber diet and those who ate a high-fiber diet. In my opinion, the conclusions of this study are questionable.
The study is purely a statistical analysis, and it contradicts the findings of other studies. In addition, it makes good physiological sense that a high-fiber diet could reduce the risk of many cancers, including colorectal cancer. As a physician, whenever I read the results of a study that doesn’t agree with common sense and sound physiological principles, I question its relevance. As is the case with many “conclusions” in medicine, tune in for the results of similar studies soon to come.
Fiber Promotes Healthy Intestinal Bacteria
Fiber promotes overall colon health by discouraging the growth of harmful bacteria in the intestines and encouraging the growth of beneficial bacteria. This is thought to contribute to the lowered risk of colorectal cancer associated with a high-fiber diet. Fiber also contributes to a friendlier intestinal environment – the friendly bacteria in the colon ferment fiber into short-chain fatty acids (SCFA’s), healthy nutrients that can be used by the body.
The friendly bacteria in the intestines seem to prefer rice bran and barley bran, balanced sources of soluble and insoluble fiber, to make these nutritious fatty acids. These foods are also rich in vitamin E compounds called “tocotrienols,” which are natural cholesterol-lowering substances.
