Fiber and Cancer: What’s the Link?

Scientists have been studying fiber for years. You’ve probably heard the headlines in the news. “High fiber diet reduces risk of colon cancer”. Then the next month “Fiber not linked to cancer risk”. It’s hard to know what the actual studies say when the news shows a brief headline based on the latest research.

Fiber is found only in plant foods. There is no question that eating a diet of mostly plant foods reduces your risk for cancer. We don’t know for sure which components of plant foods are most beneficial. My thought is that all components are important and they work together to help our bodies fight disease, including cancer.

Today I will review the latest and greatest evidence we have for the link between fiber and cancer.

The Function of Fiber

First off, it’s important to understand the function of fiber. Our bodies do not absorb fiber. We can eat it, chew it up, digest it and move it through the intestine, but it will never be absorbed through the intestinal wall into our blood. All other essential nutrients get absorbed.

So if fiber never makes it into our blood, what does it do? Fiber plays several important roles:

1. It slows the digestion of food, so you feel full longer.
2. Some fibers help lower blood sugar levels and may aid insulin sensitivity.
3. Some fibers interfere with fat and cholesterol absorption, lowering blood cholesterol and protecting your heart.

Fiber and Cancer Risk

Many studies of various populations have shown a possible link between fiber intake and reduced risk of cancer. However, it’s not clear if the risk reduction comes from the fiber, or something else in foods that provide fiber.

There are a few things that we do know about fiber and cancer. Fiber increases the amount of stool which dilutes harmful
substances and speeds their elimination from the body. Fiber also protects the lining of the colon and seems to prevent development of cancerous cells.

Get Your Fiber!

How can you get your 30 grams of fiber each day? Here’s where to start:

• Start with at least 5 vegetable and fruit servings
• Include at least three small servings of whole grains daily (such as 1⁄2 cup of oatmeal, 1⁄2 of cup brown rice, or 1 slice of whole-wheat bread)
• Have a small handful of nuts and seeds a few times weekly

Remember that if you’re increasing fiber, you want to do it SLOWLY, or you might end up having to take a day off work to be in the bathroom!

– Julie