Against the backdrop of an alarming increase in the number of people under 50 being diagnosed with bowel cancer, researchers are urging people to bump up their fibre intake and improve their eating habits if they want to reduce their risk of deadly digestive cancers.
Two studies by Flinders University expand on existing evidence that a diet rich in fruits, vegetables, whole grains, fish, legumes and dairy may protect against the risk of gastrointestinal (GI) cancers – including bowel – and improve the outcomes of these diseases.
"We've identified many direct links between poor diet choices and digestive cancers," says senior author Dr Yohannes Melaku from Flinders Health and Medical Research Institute (FHMRI).
"Importantly, we found that a diet high in healthy fats and vegetables whilst limiting the consumption of sugars and alcohol could potentially reduce the risk of bowel and other cancers.
"Unhealthy dietary patterns, marked by high consumption of red and processed meats, fast foods, refined grains, alcohol and sugary beverages, present a worrying relationship with an increased risk of GI cancers.
"Notably, we found that high-fibre foods such as fruits and vegetables promote healthy gut bacteria that can reduce inflammation. The emphasis on fibre and healthy fats should be an integral part of everyone's diet."
Whilst there is growing evidence that dietary interventions can be effective at preventing or delaying some diseases, the authors say that further trials are needed to investigate the impact that diet has on cancers and that diet is just one aspect of someone's overall health and wellbeing.
Gastrointestinal cancers (GI) including cancer of the oesophagus, stomach, pancreas, small bowel, colon, rectum and anus, are responsible for 1 in 4 cancer cases, and 1 in 3 cancer deaths worldwide.
"As awareness around bowel cancer grows, our research serves as a timely reminder of the power of nutrition in disease prevention. By adhering to healthy eating practices, we can take proactive steps in safeguarding our long-term health," says Dr Melaku.
"With the growing number of digestive cancers, such as bowel cancer, being diagnosed worldwide, and increasingly in people under 50 years old, it's time for action to protect people's digestive health."
The findings support the World Cancer Research Fund (WCRF) and American Institute for Cancer Research (AICR) guidelines that advocate for diets rich in whole grains, vegetables, fruits, and legumes, while limiting red and processed meat, sugary drinks and processed foods.
"Our findings not only reinforce established guidelines but also highlight dietary choices that can proactively protect against this disease such as upping your fibre intake," says Dr Melaku.
"Having a healthy diet is one of the simplest ways to improve our overall health and reduce the risk of diseases including cancers.
"Our studies demonstrate that nutrition education and promoting healthy eating patterns could be pivotal in reducing GI cancer risks and improving patient outcomes," Dr Melaku adds.
"Whilst our results are promising, more work needs to be done with a greater focus on nutrition in clinical settings using nutritional biomarkers to better understand the relationship between diet and GI cancer," says Associate Professor Amy Reynolds, an author on the paper.
"We need to understand how different dietary patterns may influence the risk of developing digestive cancers.
"We also want to see an increase in education around healthy eating which could lead to better health outcomes for those at risk for GI cancers," she adds.
The article, 'Association of dietary patterns derived by reduced-rank regression with colorectal cancer risk and mortality' by Zegeye Abebe, Molla Mesele Wassie, Phuc D Nguyen, Amy C Reynolds, Yohannes Adama Melaku was published in European Journal of Nutrition. DOI 10.1007/s00394-024-03513-9
A related article, 'Difference in Gastrointestinal Cancer Risk and Mortality by Dietary Pattern Analysis: A Systematic Review and Meta-Analysis by Review and Meta-Analysis' by Zegeye Abebe, Molla Mesele Wassie, Tefera Chane Mekonnen, Amy C Reynolds and Yohannes Adama Melaku was published in Nutrition Reviews journal. DOI: 10.1093/nutrit/nuae090
Acknowledgements: Y.A.M. and M.M.W. are supported by National Health and Medical Research Council of Australia (NHMRC) Investigator Grants (no. 2009776 and 2009050, respectively).
