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.
Popular Videos for Fiber
All Videos for Fiber
Foods Designed to Hijack Our Appetites
I debunk the myth of protein as the most satiating macronutrient.
Are Emulsifiers Like Carboxymethylcellulose and Polysorbate 80 Safe?
Emulsifiers are the most widely used food additive. What are they doing to our gut microbiome?
The Best Diet for Ulcerative Colitis Treatment
Plant-based diets can be 98 percent effective in keeping ulcerative colitis patients in remission, blowing away other treatments.
Preventing Inflammatory Bowel Disease with Diet
Eating a diet filled with animal products can disrupt your microbiome faster than taking an antibiotic.
Is Heme Iron the Reason Meat Is Carcinogenic?
Rectal biopsies taken before and after eating meat determine the potentially DNA-damaging dose of heme.
Heme-Induced N-Nitroso Compounds and Fat Oxidation
What do clinical studies show about the role of heme in the formation of a class of carcinogenic compounds?
The Health Effects of Mycoprotein (Quorn) Products vs. BCAAs in Meat
Clinical trials on Quorn show that it can improve satiety and help people control cholesterol, blood sugar, and insulin levels.
Are Beyond Meat and the Impossible Burger Healthy?
What happens when you compare the trans fats, saturated fat, sodium, and cholesterol levels in plant-based versus animal-based burgers?
The Health Benefits of Sorghum
Learn why sorghum is one of my favorite new grains.
Is Sorghum a Healthy Grain?
How does sorghum compare with other grains in terms of protein, antioxidants, and micronutrients? And the benefits of red sorghum compared to black and white varieties.
The Effects of Obesity on Gallstones, Acid Reflux, and Cardiovascular Disease
Sufficient, sustained weight loss may cut the risk of fatal heart attacks and strokes in half.
The Best Diet for Weight Loss and Disease Prevention
The most effective diet for weight loss may also be the healthiest.