A groundbreaking trial has unveiled the remarkable potential of resistant starch, commonly found in foods like oats and slightly green bananas, in significantly reducing the risk of various cancers. Led by experts from the Universities of Newcastle and Leeds, the study, known as CAPP2, involved nearly 1,000 participants with Lynch syndrome from around the globe.

Lynch syndrome, affecting approximately one in 300 people in the UK, stems from a genetic fault that heightens the susceptibility to bowel, womb, ovarian, and other cancers. Individuals with Lynch syndrome face up to an 80% likelihood of developing bowel cancer in their lifetime, often at a younger age than the general population. Remarkably, the trial revealed that regular consumption of resistant starch, also known as fermentable fiber, over an average of two years, slashed the incidence of cancers in other parts of the body by more than half.

Of particular note were the pronounced effects on upper gastrointestinal cancers, encompassing oesophageal, gastric, biliary tract, pancreatic, and duodenum cancers. Even more astounding was the sustained impact observed for up to 10 years after participants ceased taking the supplement.

Published in the journal Cancer Prevention Research, the study encompasses a planned double-blind, 10-year follow-up, augmented by comprehensive national cancer registry data extending up to 20 years for 369 participants. Resistant starch, a carbohydrate that resists digestion in the small intestine, instead fermenting in the large intestine to nourish beneficial gut bacteria, exhibited profound health benefits and fewer calories compared to regular starch.

Professor John Mathers from Newcastle University explained, “We believe that resistant starch may mitigate cancer development by altering bacterial metabolism of bile acids, reducing those bile acids capable of DNA damage and eventual carcinogenesis. However, further investigation is warranted.” The trial not only highlighted the efficacy of resistant starch but also underscored aspirin’s potential in reducing the risk of bowel cancer by 50%, prompting NICE’s recommendation for aspirin use among individuals at high genetic cancer risk.

Between 1999 and 2005, participants were administered either resistant starch, aspirin, or a placebo daily for two years. Although no immediate disparity was observed at the treatment stage’s conclusion, subsequent follow-up revealed a significant reduction in upper GI cancers among those who had taken resistant starch compared to the placebo group.

Professor Tim Bishop from the University of Leeds emphasized the need for further research to validate these findings, given the unexpected magnitude of the protective effect. With ongoing investigations and international trials like CaPP3, spearheaded by the same research team, the quest for safer, more effective cancer prevention strategies continues.

Funded by Cancer Research UK, the European Commission, Medical Research Council, and the National Institute for Health Research, this groundbreaking research offers hope in the fight against cancer, showcasing the transformative potential of dietary interventions in mitigating cancer risk.

By Impact Lab