Fiber

Humans evolved eating huge amounts of fiber, likely in excess of one hundred grams daily. That’s up to about ten times what the average person eats today. Because plants don’t tend to run as fast as animals, the bulk of our diet used to be made up of a lot of bulk. In addition to keeping you regular, fiber binds to toxins, such as lead and mercury, and flushes them away. (Pun intended!) Our bodies were designed to expect an ever-flowing fiber stream, so it dumps such unwanted waste products as excess cholesterol and estrogen into the intestines, assuming they will be swept away. But if you aren’t constantly filling your bowels with plant foods, the only natural source of fiber, unwanted waste products can get reabsorbed and undermine your body’s attempts at detoxifying itself. Only 3 percent of Americans may even reach the recommended minimum daily intake, making it one of the most widespread nutrient deficiencies in the United States.

In addition to its well-known effects on bowel health, high fiber intake appears to reduce the risk of cancers of the colon and breast, diabetes, heart disease, obesity, and premature death in general. A number of studies now show that high intake may also help ward off stroke. How does it protect the brain? It helps control your cholesterol and blood sugar levels, which can help reduce the amount of artery-clogging plaque in your brain’s blood vessels. High-fiber diets may also lower blood pressure, which reduces the risk of brain bleeds.

Unfortunately, about 97 percent of Americans eat fiber-deficient diets. It is naturally concentrated in only one place: whole plant foods. Processed foods have less, and animal-derived foods have none at all. Animals have bones to hold them up, but plants—and only plants—have fiber.

The information on this page has been compiled from Dr. Greger’s research. Sources for each video listed can be found by going to the video’s page and clicking on the Sources Cited tab. References may also be found at the back of his books.

Image Credit: Amanda Rae. This image has been modified.