For good health, you’ve probably been told to eat more fiber — but all fibers are not alike. If you have risk factors for coronary artery disease and stroke, such as belly fat, diabetes, high cholesterol, or obesity, it’s a good idea to know the difference. Here’s how fiber in general can add years to your life.
Dietary fibers are found naturally in plants. They’re types of carbohydrates that don’t break down in your stomach and pass through your system pretty much intact. Fiber refers to carbohydrates, such as:
Fiber is separated into two main types: soluble fiber and insoluble fiber. They’re different in how they react with water — and because of that, they have a different effect on your body.
Soluble Fiber – “The Cholesterol Sponge”
Soluble fiber dissolves in water and forms a viscous gel (soft and sticky) in the intestines which:
- Helps lower LDL cholesterol* (the “bad” cholesterol). Soluble fiber soaks up cholesterol-laden bile in your intestine and eliminates them with other waste. Per a review and analysis of multiple studies, increasing total dietary fiber by just 7 gm a day reduced stroke risk by 7% and heart disease risk by 9%. Example of 7 gm fiber: 1 medium apple + 1/2 cup cooked oatmeal OR 1/2 cup of cooked pinto beans.
- Slows down digestion which helps control blood sugar and diabetes. Diabetes is a risk factor for heart disease.
- Helps control body weight by making you feel full longer. It slows the emptying of food through the gastrointestinal tract.
- Slows visceral fat gain. A study found that eating an additional 10 grams of soluble fiber per day reduced the rate at which visceral fat accumulated (nearly 4% slower over a 5-year period).
*LDL cholesterol is needed to produce hormones and provide structure to cell membranes, but because excesses can accumulate in the blood vessels and promote atherosclerosis, it’s been branded as the “bad” cholesterol.
Sources High in Soluble Fiber
Many foods have both soluble AND insoluble fibers with some having predominantly more of one than the other.
- Oats, oat bran
- Chia seeds, ground flax seeds
- Legumes (beans, split peas, lentils)
- Psyllium husk
- Apples, avocados, pears, citrus fruits (but not fruit juices)
Insoluble Fiber – “Nature’s Broom”
Insoluble fiber acts like “nature’s broom”. It sweeps through your gastrointestinal tract and helps prevent constipation and colon cancer. Insoluble fiber does NOT dissolve in water, but absorbs water as it travels through your digestive tract which eases elimination, so it:
- Helps prevent constipation — one of the most common G.I. complaints in the U.S. — by adding bulk to your diet. (Makes your poop softer and bulkier.)
- Helps maintain bowel health by speeding up passage of food and waste through your gut.
Sources High in Insoluble Fiber
- Wheat, corn, and rice bran
- Popcorn and other whole grains (except oats)
- Fruits and veggies (specifically those with tough stalks, edible seeds, skins, and membranes), such as:
- Fibrous veggies with tough stalks like artichokes, broccoli, and Brussels sprouts.
- Fruits with edible seeds like raspberries, blackberries
How Fiber Helps Prevent Disease
- Soluble fiber soaks up potentially harmful compounds, such as unhealthy fats, before they can clog your arteries.
- Your body and brain absorb toxins from the environment as well as BPA, mercury and pesticides from the foods you eat. Insoluble fiber limits the amount of time that they lurk in your system by making them move along quickly.
- The faster these compounds and chemicals move through, you reduce the time it has to do damage.
Daily Fiber Needs
Consume 30 to 45 grams of fiber daily. You will easily meet this fiber goal if you eat the following per day.
- 3 servings of fruits
- 5+ servings of vegetables
- 1 serving of beans/legumes
- 1 serving of chia seeds and/or ground flax seeds
- 2+ servings of whole grains
Fit Tip: Fiber is being linked to improved immunity and anti-inflammatory effects. Chronic inflammation plays a role in heart attack and stroke. Snack on nuts and seeds, roasted chickpeas, air-popped popcorn. Spread avocado on your toast and sandwiches instead of butter or mayonnaise.