The National Cancer Institute reported over 101,000 new cases of colon cancer in 2011, with close to 50,000 deaths from colorectal cancers. Medical experts studying ways to prevent colon cancer often focus on dietary changes, with fiber one of the leading contenders. However, research results are mixed, particularly concerning fiber supplements such as psyllium.
Colon Cancer
Cancer occurs when there is damage to the DNA in cells in your body, and they begin to grow out of control. Ordinarily, healthy cells grow, divide and die, but abnormal cancer cells continue to grow and don’t die off, creating even more damaged cells. The majority of colon cancer cases start as small clumps of cells called polyps in your large intestine, many of which are benign, or nonharmful. If polyps are removed early, they can't turn into cancerous growths.
Psyllium Benefits
Psyllium refers to any of 200 members of the plant genus Plantago, although the two species commonly known as black and blond psyllium are the most common. The seeds of these plants are milled and ground to release their mucilage content, a clear, colorless gel compound used primarily as a laxative. Psyllium is a soluble fiber, meaning it attracts water to form a gel, which slows down digestion and makes you feel full. The soluble fiber in psyllium can help lower cholesterol.
Scientific Evidence
A 1988 study at the Memorial Sloan-Kettering Cancer Center published in "Cancer Letters" discovered that psyllium fiber had a protective effect against damage to the thin layer of cells lining the walls of the colon. When researchers combined psyllium with wheat bran, in a study published in 1996 in "Mutation Research," they found it led to even greater protection against the formation of cancerous cells in the colon. Scientists in Madrid, Spain, were able to link psyllium intake to a reduction in colon cancer risk in a year-long study reported in the October 2002 issue of the "European Journal of Cancer Prevention."
Contradictory Research
Adenomas are a type of benign tumor that account for three-quarters of all colon polyps, but they may become cancerous if not removed. A team in France divided 665 patients with a history of colorectal adenomas to three treatment groups, those receiving calcium, fiber or a placebo, for three years. The team discovered the calcium group had a 16 percent chance of adenoma recurrence. The psyllium fiber group had a 30 percent chance of developing a new adenoma, which increased substantially if the patient was also taking calcium. The conclusion, published in the journal "Lancet" in October 2000, was that supplementation with psyllium could have adverse effects on colorectal adenoma recurrence, especially in patients with high dietary calcium intake.
Considerations
Psyllium supplements can affect the absorption of medications, so avoid taking any medications at the same time as psyllium. If you are switching from a low-fiber diet to using psyllium fiber supplements, start with a low dose to avoid bloating, gas and diarrhea. Increasing your water consumption can also help avoid side effects. Psyllium is generally considered safe, although there is one case report of a severe allergic reaction. Contact your doctor immediately if you take psyllium and develop hives, difficulty breathing and swelling.
References
- National Cancer Institute: Colon and Rectal Cancer
- American Cancer Society: Colorectal Cancer
- University of Maryland Medical Center; Psyllium; Steven D. Ehrlich, N.M.D; May 2009
- Purdue University Horticulture Department: Psyllium
- "Cancer Letters"; Effects of Psyllium Fiber and Short-Chain Organic Acids Derived from Fiber Breakdown on Colonic Epithelial Cells from High-Risk Patients; E. Friedman, et al.; December 1988
- "Mutation Research"; Dietary Fiber and the Chemopreventive Modelation of Colon Carcinogenesis; O. Alabaster; February 1996
