Getting the Scoop on Fiber

Who cares about fiber? Isn’t it just for old people?

Bowel habit questions are near the top of my list for patient questions. From mothers who worry about their child’s constipation, to young people with bloating or diarrhea, to old people worried about regularity, some days my practice feels like one long fiber conversation. That concern makes fiber a big business in this country—a billion dollar a year business. In fact, all of the “colon cleansing” and colon health products on the market are mostly just fiber.

What Is Fiber?

Fiber is food material that cannot be digested by our intestinal enzymes — it passes through our digestive tract without being digested or absorbed. There are two major types of fiber:

1. Insoluble Fiber
This type of fiber is what most people think of. Insoluble fiber is found in whole grains, fruit and vegetable skin, and seeds and nuts. It is a stool bulking agent that absorbs water. This fiber promotes bowel movements and prevents constipation when consumed with sufficient amounts of water. Insoluble fiber improves bowel motility (how fast the poop moves through) which helps remove toxins created by digestion, and dangerous substances created by the bacteria in the colon. One of the most important concepts with regard to insoluble fiber is drinking lots of water. Since the insoluble fiber acts like a sponge, it needs water to be effective. People typically don’t drink enough water with the fiber pills they’re taking and the fiber causes bloating and constipation. Insoluble fiber forms a gel when mixed with water and never fully dissolves.

2. Soluble Fiber
Think of this type of fiber as a way to slow absorption of sugars, carbohydrates, and fats. Soluble fiber also binds cholesterol in the intestines and can lower cholesterol in some people. This type of fiber dissolves fully in water and won’t be gritty or clumpy. Foods that are sources of soluble fiber help diabetics control blood sugar because they slow the time it takes for sugar to get from the intestines to the blood stream. Typically, this type of fiber is on the inside of fruits and vegetables, grains and nuts, while insoluble fiber tends to be in the skin and outer layer.

You need both types of fiber for good health. Luckily, fruits and vegetables have a healthy mix of both types. I try to encourage people to eat the SuperFoods because they have a natural mix of soluble and insoluble fiber. I don’t encourage fiber supplements as much, because they lack the powerful antioxidants of fruits and vegetables and nuts and seeds. I want my patients to eat a balanced, healthy diet, and I see many people taking fiber products while still eating an unhealthy, processed, fast-food diet. They’re missing the point.

A diet low in fiber leads to bowel irregularity. Typically, people who don’t eat enough fiber swing back and forth between cramping diarrhea and bloating constipation. Hard, low volume, pellet-like stool from a low fiber diet injures the intestines and causes colon polyps and thin-walled pouches called diverticuli to develop. People of all ages can benefit from both the digestive and health benefits of fiber in their diet. I recommend that people get their fiber from the foods they eat.

Fiber Benefits

1. Regulates bowel habits
2. Stool bulking agent that helps prevent diverticular disease
3. Removes toxins and bacterial by-products from the colon
4. Binds cholesterol and can lower LDL (bad cholesterol) levels
5. Slows absorption of sugars and fats
6. Has been shown to lower the risk of developing colon cancer and colon polyps
7. Lowers the risk of heart disease
8. Improves irritable bowel syndrome (IBS)
9. Encourages the growth of helpful bacteria in the colon (probiotics)
10. Helps regulate the immune system by discouraging the growth of detrimental bacteria and yeast