An online survey of more than 27,000 from around the world found that respondents who exercised more, followed a healthy diet and did not smoke were less likely to have a personal history of colorectal cancer or colon polyps.
An online survey has numerous confounders, due to selection and recall bias, but it makes sense that lifestyle factors would impact cancer rates. Some of the others are less clear. For example, Carol A. Burke, MD, a Cleveland Clinic gastroenterologist and the current president of the American College of Gastroenterology, says "Colon cancer is a preventable disease", which is the kind of thing Cleveland Clinic has become famous for - they will sell you some sort of naturopathic or fad diet regimen if you want also - but not evidence-based. Only 36 percent of respondents were up to date with current colorectal screening so the overwhelming majority could have cancer and not know it, regardless of how many vegetables they ate.
The five-minute web-based questionnaire, which can be found at clevelandclinic.org/preventcoloncancer, asks respondents about age, gender, ethnicity, height, weight, dietary factors, smoking history, physical activity, personal and family history of colorectal cancer or polyps, and adherence to screening.
The results showed that the respondents more likely to be adherent to colorectal cancer screening were white and female. They also had less exposure to cigarettes, ate more daily servings of a plant-based diet and exercised more than those who were not up to date with screening. The data also indicated that respondents with a first-degree relative with colorectal cancer and polyps were significantly more likely to adhere to screening: 35.7 percent were adherent compared with 19.4 percent of participants without an affected first-degree relative.
After completing the survey, participants get a score of average, or above average at low, medium or high risk of colorectal cancer based on reported personal and family history of colorectal cancer, polyps or both. They also receive a family tree showing the relatives reported to be affected with colorectal cancer or polyps and a call to action outlining what age to start screening and how frequently it should be done.
The results were presented in two separate analyses yesterday at Digestive Disease Week 2017.