Resistant starch may have a significant role to play in keeping certain diseases at bay according to a new study that looked at people with a hereditary risk of a wide range of cancers. Found in oats, cereals, green bananas as well as cooked and cooled pasta and rice, the fermentable fiber, as resistant starch is also known, was found to reduce the risk of certain cancers in people by more than a half.
The long-term study followed almost 1,000 patients with Lynch syndrome, a hereditary condition which puts people at a higher risk of developing certain cancers before the age of 50. Its findings were published in Cancer Prevention Research, a journal of the American Association for Cancer Research.
“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,” explained Professor John Mathers, professor of Human Nutrition at Newcastle University, in a statement emailed to IFLScience. “This is important as cancers of the upper GI tract are difficult to diagnose and often are not caught early on.”
The findings pertain specifically to resistant starch, a type of carbohydrate which ferments in the large intestine where it feeds “good” bacteria. As for how it may reduce cancer development, the researchers suggest it may alter the bacterial metabolism of acids in the gut which can damage it, increasing the risk of cancer.
However, further investigations are needed to confirm this.
The benefits of resistant starch in lowering cancer risk wasn’t consistent across all disease types, but for certain cancers the risk dropped by more than half. The effect was seen in people who took a resistant starch powder supplement every day for two years and continued even 10 years after stopping the supplement.
Upper gastrointestinal cancers were particularly associated with improvements under the starch regime, including esophageal, gastric, biliary tract, pancreatic and duodenum cancers. The study also found that aspirin carried benefits for people with Lynch syndrome, reducing the risk of cancers of the large bowel by half.
“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 study co-lead Professor Sir John Burn of Newcastle University and Newcastle Hospitals NHS Foundation Trust.
“Patients with Lynch syndrome are high risk as they are more likely to develop cancers so finding that aspirin can reduce the risk of large bowel cancers and resistant starch other cancers by half is vitally important. 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.”
While a promising insight into the effect of resistant starch supplements on certain cancers for certain people, the researchers warn that further investigations are needed to cement the conclusions.
“The results are exciting but the magnitude of the protective effect in the upper GI tract was unexpected so further research is required to replicate these findings,” said Professor Tim Bishop, at the University of Leeds, who also helped to run the trials.