Findings in a new trial show that dietary supplementation of resistant starch has the potential to decrease people’s risk of certain types of gastrointestinal cancers.
For people with a high risk of hereditary cancer, resistant starch may be a major preventative measure against a wide range of cancers, according to an international trial. Resistant starches are high in foods such as oats, breakfast cereal, cooked and cooled pasta or rice, peas, beans, and slightly green bananas.
Resistant starch, also called fermentable fiber, was found to reduce some cancers in the body by 50% in the CAPP2 trial, a planned and double blind 10-year follow-up of an earlier study examining the effects of aspirin on cancer risk for patients with Lynch syndrome. This first trial found that aspirin can reduce the risk of large bowel cancer by 50%.
“Resistant starch can be taken as a powder supplement and is found naturally in peas, beans, oats and other starchy foods. The dose used in the trial is equivalent to eating a daily banana; before they become too ripe and soft, the starch in bananas resists breakdown and reaches the bowel where it can change the type of bacteria that live there,” said John Mathers, a professor of Human Nutrition at Newcastle University, in a press release.
The CAPP2 trial studied the effects of dosed fermentable fiber on 1000 international patients suffering from Lynch syndrome. For an average of 2 years, participants took a regular supplement of resistant starch. Improvements were unnoticeable for bowel cancers, but participants reduced their risk of getting upper gastrointestinal (GI) cancers by 50%. Upper GI cancers include esophageal, gastric, biliary tract, pancreatic, and duodenum cancers.
“We found that resistant starch reduces a range of cancers by over 60%. The effect was most obvious in the upper part of the gut,” Mathers said in the release. “This is important as cancers of the upper GI tract are difficult to diagnose and often are not caught early on.”
The current study was just published by experts in the UK at the universities of Newcastle and Leeds on July 25, 2022, in the journal Cancer Prevention Research, part of the American Association for Cancer Research. Evidence even showed that the anti-cancer effects of resistant starch lasted 10 years after patients stopping supplementation.
“When we started the studies over 20 years ago, we thought that people with a genetic predisposition to colon cancer could help us to test whether we could reduce the risk of cancer with either aspirin or resistant starch,” said Sir John Burn, professor at Newcastle University, Newcastle Hospitals NHS Foundation Trust, and co-leader of the trial, in a press release. “…finding that aspirin can reduce the risk of large bowel cancers and resistant starch other cancers by half is vitally important.”
Currently, researchers are examining the effects of small, safe doses of aspirin on reducing cancer risk for 1800 Lynch syndrome patients in the international CaPP3 trial.
“Based on our trial, NICE now recommend aspirin for people at high genetic risk of cancer, the benefits are clear—aspirin and resistant starch work,” Burn said in a press release.
First trial to prove a diet supplement can prevent hereditary cancer. EurekAlert!. July 25, 2022. Accessed July 26, 2022. https://www.eurekalert.org/news-releases/959650