Obesity and lack of physical activity are undisputed risk factors for colon cancer.
Obesity appears to be a source of chronic inflammation in the body and this adversely affects multiple organ systems and contributes to the formation of cancer.
Obese individuals are more likely to be diagnosed with colon cancer. For every 5% increase in BMI (body mass index), the risk for developing colon cancer increases by 18%. This risk is greater for men than women.
It is important to understand BMI which is used in science and medicine to determine obesity. It factors in a patient’s weight and body surface area. The easiest way to understand BMI is to look at a BMI chart that compares weight with height. There are separate BMI charts for children and adults. The adult BMI chart applies to both men and women.
Body Mass Index (BMI)
Below 18.5 = Underweight
18.5 – 24.9 = Normal
25.0 – 29.9 = Overweight
30.0 and Above = Obese
Obese patients have a worse prognosis when diagnosed with colon cancer. Exercise can significantly reduce the risk of death in patients who have been diagnosed with colon cancer.
One can lower the risk of colon cancer by increasing recreational physical activity. Interestingly, this benefit of exercise was shown even among patients who continued to remain obese. Ideally, one would want to exercise and try achieve a normal body weight (BMI = 25). Patients with higher levels of physical activity can reduce their risk of colon cancer by 30-40% compared to those who are sedentary, regardless of BMI.
How much physical activity is recommended? Studies show that by engaging in 150 minutes of physical activity per week, one could lower the risk for cardiovascular mortality and all-cause mortality including from colon cancer.
How much weight should one lose? A healthy rate should be to lose no more than 2 pounds per week and this should be achieved through exercise and a proper healthy diet. A healthy diet should include nutrient-rich foods such as fruits, vegetables and whole grains which contain phytochemicals (for example Curcumin) which have a chemoprotective effect on the development of colon polyps and cancer. See my Fiber Guide for ideas on healthy food items.
Here’s to your colon health!
Frank Farrell, MD, MPH, AGAF