Lynch syndrome is a disease that is due to the alteration of a gene and that is characterized by a genetic predisposition to develop hereditary colorectal cancer and also increases the risk of suffering from other types of cancer. Now, a new clinical trial involving 918 patients with Lynch syndrome – who as a result had a high hereditary risk of different cancers – has shown that resistant starch – found in foods such as slightly green bananas or oatmeal, among others – helps prevent the onset of cancer.
In the study – called CAPP2 – it was found that eating a regular dose of resistant starch (in powder form) for an average of two years did not affect cancers in the intestine, but decreased the presence of cancer in other areas of the body more than half, something that was seen especially in the case of upper gastrointestinal cancers, including cancers of the esophagus, gastric, bile duct, pancreas and duodenum. In addition, its effect was maintained 10 years after stopping taking the supplement.
The research has been led by scientists from the University of Newcastle and the University of Leeds and has been published in Cancer Prevention Research, a journal of the American Association for Cancer Research. “We found that resistant starch reduces a variety of cancers by more than 60%. The effect was more evident in the upper part of the intestine”, explained John Mathers, Professor of Human Nutrition at the University of Newcastle. “This is important as cancers of the upper gastrointestinal tract are difficult to diagnose and are often not detected early.”
Dose of resistant starch equivalent to eating a banana daily
Resistant starch, also known as fermentable fiber, can also be found in cooked and chilled breakfast cereals, pasta and rice, peas and beans. “Resistant starch can be taken as a powdered supplement and is found naturally in peas, beans, oatmeal and other starchy foods. The dose used in the trial is equivalent to eating a banana daily; before they get too ripe and mushy, the starch in the bananas resists breakdown and makes its way to the intestine, where it can change the type of bacteria that lives there.”
“We believe that resistant starch may reduce cancer development by changing the bacterial metabolism of bile acids and reducing those that can damage our DNA and cause cancer.”
“Resistant starch is a type of carbohydrate that is not digested in the small intestine, but instead is fermented in the large intestine and feeds beneficial gut bacteria; in effect, it acts like dietary fiber in the digestive system. This type of starch has several health benefits and fewer calories than regular starch. We believe that resistant starch may reduce cancer development by changing the bacterial metabolism of bile acids and reducing those types of bile acids that can damage our DNA and eventually cause cancer. However, this needs more research.”
Aspirin or starch to reduce cancer risk
Between 1999 and 2005, study participants began taking resistant starch in powder form daily or aspirin, or a placebo (a powder that looks similar to resistant starch but is inactive) for two years. At the end of the treatment period, no differences were found between those who had taken aspirin or resistant starch and those who had not.
However, the researchers anticipated a longer-term effect and designed the study for later follow-up. During the follow-up phase, only five new cases of upper gastrointestinal cancers occurred among the 463 participants who had taken the resistant starch, compared with 21 among the 455 who received the placebo. Previous research that has been published as part of the same trial showed that aspirin reduced cancer of the large intestine by 50%.
Professor Sir John Burn, of Newcastle University and Newcastle Hospitals NHS Foundation Trust, who led the trial with Professor Mathers, said: “When we started the studies over 20 years ago, we thought that people with a genetic predisposition to cancer colon cancer could help us test whether we could reduce the risk of cancer with aspirin or resistant starch.”
“Patients with Lynch syndrome are at high risk, as they are more likely to develop cancers, so it is vitally important to discover that aspirin can halve the risk of large intestine cancers and other resistant cancers. to starch.
Professor Tim Bishop, from the University of Leeds, who also led the work concludes: “The results are exciting, but the magnitude of the protective effect in the upper gastrointestinal tract was unexpected, so further research is required to replicate these findings.” . The team of scientists is currently leading the international CaPP3 trial, involving more than 1,800 people with Lynch syndrome, which will evaluate the possibility of using smaller and safer doses of aspirin to help reduce the risk of cancer. .
.
