Fiber and Colon Cancer
Snack food, cereal, and other processed food companies have pushed fiber to be an important part of the human diet, as they claim it helps people avoid colon cancer:
“New England Journal of Medicine editorial that accompanied back-to-back April 2000 reports on two major trials—one on fourteen hundred subjects of the Phoenix [Arizona] Colon Cancer Prevention Physicians’ Network, and one $30 million trial from the National Cancer Institute—both of which confirmed that fiber had no effect on colon cancer.”
Taubes, Gary. (2011). Good Calories, Bad Calories: Fats, Carbs, and the Controversial Science of Diet and Health. Blackstone Publishing.
I’m thinking maybe they’ve all been lying to us for years now. Fiber is not good for you. Don’t eat it.
Fiber and Digestive System Tumors
We’ve also been told that it helps to protect from digestive system tumors. Also untrue. For example:
“The results of this study show that neither fiber intake from a wheat bran supplement nor total fiber intake affects the recurrence of colorectal adenomas (non-cancer tumors), thus lending further evidence to the body of literature indicating that consumption of a high-fiber diet, does not reduce the risk of colorectal adenoma recurrence.”
Jacobs, E. T., Giuliano, A. R., Roe, D. J., Guillén-Rodríguez, J. M., Hess, L. M., Alberts, D. S., & Martínez, M. E. (2002). Intake of supplemental and total fiber and risk of colorectal adenoma recurrence in the wheat bran fiber trial. Cancer epidemiology, biomarkers & prevention: a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology, 11(9), 906–914.
Fiber and Diverticulosis
Fiber increases the likelihood of diverticulosis. It does not decrease it like we’ve been misled to believe.
“We were surprised to find that a low-fiber diet was not associated with a higher prevalence of asymptomatic diverticulosis,” said Peery. In fact, the study found those with the lowest fiber intake were 30 percent less likely to develop diverticula than those with the highest fiber intake.
A high-fiber diet and increased frequency of bowel movements are associated with greater, rather than lower, the prevalence of diverticulosis. Hypotheses regarding risk factors for asymptomatic diverticulosis should be reconsidered.
Peery, A. F., Barrett, P. R., Park, D., Rogers, A. J., Galanko, J. A., Martin, C. F., & Sandler, R. S. (2012). A high-fiber diet does not protect against asymptomatic diverticulosis. Gastroenterology, 142(2), 266-272.
So Stop Worrying About Fiber
“A strong case cannot be made for a protective effect of dietary fiber against colorectal polyp or cancer. Neither has fiber been found to be useful in chronic constipation and irritable bowel syndrome. It is also not useful in the treatment of perianal conditions.”
Fiber serves no purpose in human digestion.
Tan, K. Y., & Seow-Choen, F. (2007). Fiber and colorectal diseases: separating fact from fiction. World journal of gastroenterology: WJG, 13(31), 4161.