Preventing Colorectal Cancer: Research Findings and Questions
When it comes to what you eat, your weight, and how much you move, colorectal cancer is one of the most preventable cancers. AICR estimates that 50 percent of all cases could be prevented with healthy lifestyle habits. For National Colorectal Cancer Awareness Month we're breaking down what the research is clear about and some big questions that AICR-supported scientists and many others are studying.
Here's what we know, based on the latest research from AICR's Continuous Update Project report on preventing colorectal cancer:
- Be a healthy weight. Overweight and obesity increase risk of this cancer; the more excess body fat, the higher the risk. Aside from not smoking, staying a healthy weight is the most important lifestyle-related factor that can decrease cancer risk.
- Eat Healthy. Foods containing fiber and garlic are two factors that decrease risk; red meat and processed meat increase risk. AICR recommends avoiding processed meats like hot dogs and bacon, and eating no more than 18 ounces of red meat a week -- a small burger is about 3 ounces. Another recommendation is to eat plenty of various vegetables, fruits, whole grains and beans. Many contain lots of fiber and a plant-food based diet can also help you get to- and stay - a healthy weight.
- Be physically active. Being physically active decreases risk. AICR recommends being moderately active in some way at least 30 minutes a day, working up to 60 minutes or more of moderate, or 30 minutes of vigorous activity every day.
- If you drink at all, drink in moderation. For both men and women, drinking alcohol increases risk. If you do drink alcohol, AICR recommends that men drink no more than two drinks a day and women no more than one.
Research Hot Topics
How does our microbiome affect colorectal cancer risk? Our body is teeming with bacteria and other microbes, known as the microbiome, which we need to stay healthy. Researchers are only beginning to identify the numerous types and functions of the thriving bacteria community in our gut. When we eat fiber, gut bacteria metabolize fiber to produce a compound called butyrate. The more fiber people eat, the more butyrate produced. And in lab studies, butyrate shows protection against colon cancer.
But as scientists are learning, not all bacteria digest fiber in the same way and we all have different bacteria. Questions on which and how bacteria digest fiber are under study. Scientists are also investigating the role of butyrate in colon cancer prevention.
You can read more in Discovering How Fiber Fights Cancer.
Can diet affect colorectal cancer stem cells? Stems cells have the potential to develop into different cell types, such as skin, bone, and layers of the intestine. They also can develop into cancer cells that start the cancer process. Scientists are investigating the biology of stem cells that may drive colorectal cancer. An AICR-funded scientist at Texas A&M University is investigating whether these stem cells are affected by diet.
You can read more in Meet our Newest Grantees.
How can different foods work together to prevent colorectal cancer? When we eat a fruit, vegetable or other plant food our body is taking in a unique combination of vitamins, minerals and phytochemicals. Every year, scientists identify more phytochemicals and better understand how they function. What is more challenging, yet relevant, is finding out how the many compounds in foods we eat work synergistically.
For example, charred red meat produces carcinogens, called heterocyclic amines, or HCAs. If you had broccoli or carrots with that piece of charred meat, would that reduce the formation of HCAs? That's what one scientist at the University of Minnesota is investigating.
You can read more about that research in What to Eat with Your Burger: Scientist in the Spotlight.