March is Colorectal Cancer Awareness Month, which serves as a great time to remind ourselves to discuss lifestyle factors that contribute to the risk of developing or experiencing a recurrence of colorectal cancer. Our dietary decisions, daily habits and behaviours can have profound influence on our risk of colorectal cancer, as highlighted by a recent 2022 study. 

This study investigated the impact of smoking, alcohol, body mass index (BMI) and physical activity on colorectal cancer risk. The study included 295,865 middle-aged adults, observed over an average of 7.8 years. Researchers calculated the healthy lifestyle index (HLI) for each study participant, which ranged from 0 (least healthy) to 16 (most healthy) for smoking status, alcohol consumption, body mass index, and physical activity, at baseline and follow-up. In general, the results found that there was significantly lower risk of colorectal cancer in association with lesser alcohol consumption and smoking levels, and higher physical activity and healthier weight (BMI) scores. 

In addition, researchers found a significant 3% lower colorectal cancer risk per unit increment in the HLI score from baseline to follow-up. In other words, the more people adhered to healthy lifestyle habits, the lesser their risk was of colorectal cancer. What is also important to note is that those who improved their lifestyle habits over time were able to decrease their risk compared to those that did not change, even if they had similar scores at baseline. Improving from a less healthy lifestyle (score of 0-9) to a healthier lifestyle (score of 12-16) was connected to a 23% reduced risk of colorectal cancer, which is huge! In contrast, regression from a healthy lifestyle (score 12-16) to an unhealthy lifestyle (score 0-9) was associated with a 34% higher risk of colorectal cancer. 

In summary, maintaining a healthy lifestyle or changing lifestyle habits over time can have powerful impacts on colorectal cancer risk. Below are the most recent diet/lifestyle recommendations made by American Institute of Cancer Research (AICR) for reducing risk, based on research like the study above: 

• Eat a whole-food, plant-based diet high in fiber, which includes a variety of fruits, vegetables, beans, and whole grains. 


• Avoid processed meats, such as cold cuts, bacon, sausage, and hot dogs. 


• Limit intake of red meats, including beef, pork, and lamb, to 18 oz (cooked) per week. 


• 3 oz portion is similar in size to a deck of cards 


• Reduce excess body fat. 


• Engage in regular physical activity, aiming for about 30 minutes per day. 


• Limit alcohol intake to no more than 2 drinks per week. 


• Quit smoking. 

Author: Helya Bahmanpour, CCNM Integrative Cancer Centre Intern