Fiber is a type of indigestible carbohydrate. Dietary fiber is an essential component of a healthful diet, with research linking a high fiber diet with reduced risks of many health conditions, including cardiovascular disease, type 2 diabetes, and certain cancers. Fiber is also important for keeping the gut healthy.
Consumption of dietary fiber has decreased dramatically in the last century. Most people do not meet their adequate daily requirement of fiber. That is likely due to lower consumption of plant-based foods and increased intake of low-fiber processed foods.
What is Dietary Fiber?
Dietary fiber, also known as roughage, is the indigestible part of plant foods. Most carbohydrates are broken down into sugar molecules, but fiber passes through your body without being digested. Dietary fiber is primarily derived from plant material and is composed of complex, nonstarch carbohydrates and lignin that are not digestible within the small intestine because mammals do not produce enzymes capable of hydrolyzing them into their constituent monomers.
As a result, these compounds make it to the colon intact, where they are available for fermentation by the resident bacteria.Dietary fiber is considered to contribute no calories to our diet.
High Fiber Diets Foster Heart Health
People who eat high fiber diets have significantly reduced risk of cardiovascular disease and lower mortality from these conditions. Dietary fiber may reduce the risk of coronary heart disease through a variety of mechanisms, such as improving blood lipid profiles, lowering blood pressure and improving insulin sensitivity and fibrinolytic activity. Dietary fiber has been found to be inversely associated with risk factors for coronary heart disease in observational studies.
Dietary Fiber and the Gut Microbiota
Fiber is important for keeping the gut healthy. It also encourages healthy gut microbiota. High fiber diet has major effect on Gut Microbiome. Even just two weeks of a high-fiber diet can have a significant effect on the gut microbiome and could lead to better nutrient absorption, according to a recent study.
The gut bacteria metabolize this type of fiber into short-chain fatty acids, which are the main source of nutrition for the colon’s cells. These fatty acids have also been linked to lower risk for: inflammatory diseases, obesity, cardiovascular disease and type 2 diabetes.
Poor gut health has been connected with increased colorectal cancer risk and prevalence of autoimmune diseases, and that it could even decrease vaccine efficacy and response to cancer immunotherapy. Imbalances in gut health can make people more susceptible to infections, chronic inflammation, and cancer.
Dietary fiber increases the bulk of stool, helps promote regular bowel movements, and reduces the time that waste spends inside the intestines. Dietary fiber has a positive impact on gastrointestinal disorders, including: colorectal ulcer, hiatal hernias, gastroesophageal reflux disease, diverticular disease and hemorrhoids.
Fiber Boosts the Immune System
Fiber can support your immune health and digestion by encouraging regular bowel movement and providing the “food” for the good bacteria in your gut to feed off of. Like all living organisms, even the bacteria in our bodies need fuel to survive and the fiber in our daily diets is what provides that food.
This good bacteria “food” is known as prebiotics, which can be found in certain types of fiber-rich foods like jackfruit, garlic, and onions. By fueling the “good” gut bacteria with prebiotic fiber-rich foods we can promote better digestive health, immune health, as well as many other promising health outcomes.
Fiber Helps Manage Diabetes
Fiber can help slow down the body’s absorption of sugar, helping to prevent blood sugar spikes after meals. People who ate high fiber diets, especially cereal fiber, had a lower risk of developing type 2 diabetes. These individuals also reported a small reduction in blood glucose levels.
HbA1c is the glycated haemoglobin. That’s made when the glucose (sugar) in your body sticks to your red blood cells. Your body can’t use the sugar properly, so more of it sticks to your blood cells and builds up in your blood. Red blood cells are active for around 2-3 months, which is why the reading is taken quarterly. HbA1c is the average blood glucose (sugar) levels for the last three months. If you have diabetes, an ideal HbA1c level is 48mmol/mol (6.5%) or below. If you’re at risk of developing type 2 diabetes, your target HbA1c level should be below 42mmol/mol (6%).Fiber supplementation for type 2 diabetes mellitus can reduce fasting blood glucose and HbA1c.
The Glycemic Index
The glycemic index is a value used to measure how much specific foods increase blood sugar levels. Soluble fiber, lowers glycemic index. Foods high in soluble fiber such as oats, barley, and legumes (dried beans and lentils) have low glycemic index values.
Both microvascular and macrovascular complications are thought to be due to prolonged hyperglycemia, which promotes an increase in oxidative stress, inflammation, and vascular damage. Evidence indicates that medical interventions designed to lower blood glucose concentrations can reduce the risk of developing microvascular and macrovascular complications. One of these interventions includes a low glycemic index diet.
The low glycemic diet involves swapping out foods with a high glycemic index for those with a lower glycemic index .Following a low glycemic diet may offer several health benefits. Many studies have found that following a low glycemic index diet may reduce blood sugar levels and improve blood sugar management in people with type 2 diabetes. Some research shows that following a low glycemic index diet may increase short-term weight loss. Following a low glycemic index diet may improve glucose metabolism and lipid profile in type 2 diabetes patients.
Weight Management
For people aiming to lose weight, a diet high in dietary fiber can help regulate weight loss. High fiber foods help a person feel fuller for longer and may help people adhere to a diet. People who increased their dietary fiber intake increased their weight loss and adherence to their dietary caloric restriction.
Types of Dietary Fiber
Soluble and insoluble are the two types of dietary fiber. Most high fiber containing foods have both insoluble and soluble fiber, so people do not need to think much about the difference. Instead, they can focus on overall fiber intake.
Soluble fiber dissolves in water and forms a gel-like substance in the stomach. Bacteria later break the gel down in the large intestine. Soluble fiber provides some calories to the individual. Soluble fiber provides the following benefits: lowering LDL cholesterol in the blood by affecting how the body absorbs dietary fat and cholesterol, slowing absorption of other carbohydrates through digestion, which can help regulate blood sugar levels. Good sources of soluble fiber include: beans, fruits, oats, nuts and vegetables.
Insoluble fiber does not dissolve in water and passes through the gastrointestinal tract, mostly intact. It does not provide calories. Insoluble fiber helps build bulk in the stool, helping a person pass stool more quickly. It can also help prevent constipation. Good sources of insoluble fiber include: fruits, nuts, vegetables and whole grain foods.
Tips to Increase Fiber
People can boost their daily fiber intake by making a variety of small changes. Eat fruits and vegetables with the skins on, as the skins contain lots of fiber. Lean on legumes. Beans, peas and lentils are excellent sources of fiber. Add beans or lentils to salads, soups, and side dishes. Switch to whole grains. Replace white breads and pastas for whole wheat versions. Aim to eat 4.5 cups of vegetables and 4.5 cups of fruit each day. Spices are generally high in fiber and low in sugar and sodium.
Nuts and seeds high in fiber include chia seeds, flax seeds, squash seeds, pumpkin seeds, dried coconut, sesame seeds, sunflower seeds, almonds, pine nuts, pistachios, and chestnuts.
If unable to meet the daily requirements, consider using fiber supplements. Also, drink plenty of water. Fiber works best when it absorbs water, making your stool soft and bulky.
