Voedingsvezels en vitamine tegen kanker*
Voedingsvezels staan al langer bekend als goede oplossing bij constipatie en de bescherming tegen darmkanker. Uit deze studie blijkt nu dat voedingsvezels samen met goede bacteriën in de darmen ook kanker bestrijdt
door een proteïne te activeren waardoor kankercellen gedood worden. Voedingsvezels worden in de darm door bacteriën verwerkt waarbij als metaboliet butyraat (zout van boterzuur) ontstaat. Dit butyraat activeert het proteïne GPR109A. Dit proteïne zorgt voor de dood van kankercellen en gaat ook ontstekingen tegen, ontstekingen die kunnen leiden tot kanker. Ook
vitamine B3 doet het proteïne GPR109A activeren. Grote hoeveelheden butyraat zouden volgens de wetenschappers goed werk kunnen doen bij kanker doch butyraat smaakt verschrikkelijk vandaar dat het beter is grote hoeveelheden voedingsvezels en vitamine B3 te nemen.
Fiber Activates Natural Cancer-Killer
You've probably heard that including a lot of fiber in your diet will help prevent constipation and reduce your risk of colon cancer, too. But now scientists at the Medical College of Georgia (MCG) have discovered that roughage does more to actively fight cancer than anyone realized before -- incredibly, roughage works with beneficial bacteria in the colon to activate a receptor in the body that can kill
cancer.
The research, just published in the journal Cancer Research, concludes that a receptor dubbed GPR109A is activated by butyrate, a metabolite produced by fiber-eating bacteria found in the colon. The result? The receptor sends signals that cause a process known as apoptosis, the death of cancer cells. What's more, the receptor also blocks a protein that causes inflammation. That's important because inflammation is known to be a precursor to
cancer.
"We know the receptor is silenced in cancer but it's not like the gene goes away," Dr. Vadivel Ganapathy, corresponding author and chair of the Department of Biochemistry and Molecular Biology in the MCG School of Medicine, said in a statement to media.
Cancer typically gets the upper hand because the disease can shut down the cancer-fighting receptor by chemically modifying its gene. This process, technically known as DNA methylation, allows malignancies to turn genes off that would thwart the cancer's growth. That explains why drug companies are working on therapies called DNA methylation inhibitors as possible cancer treatments. But it appears eating large amounts of roughage could activate butyrate and fight cancer, naturally.
"Colon cancer does not want butyrate produced by bacteria to come inside so it silences the transporter. It also does not want butyrate to act on the cell from the outside so it silences the receptor," Dr. Ganapathy explained in the media statement. "It does not want to have anything to do with butyrate... We think receptor activation by butyrate suppresses inflammation, thereby suppressing progression of inflamed cells into cancer
cells."
The MCG researchers suggest cancer patients could benefit by taking high doses of butyrate -- but the substance tastes terrible. Instead, Dr. Ganapathy has suggested taking large amounts of the B vitamin niacin; this could spur the same anti-cancer activity that butyrate does, so it may prove to be a good substitute. Moreover, he is planning to conduct clinical trials that compare the course of colon cancer patients who eat a high fiber diet or receive butyrate or niacin therapy along with taking DNA methylation inhibitors that activate GPR109A.
Interested in taking control of your colon cancer risk? In addition to increasing the amount of fiber in your diet, the National Institutes of Health advises exercising regularly, reducing or eliminating red meat and processed foods and consuming a wide variety of fruits and
vegetables. (Mei
2009)
