A recent study has assessed the combined effect of healthy lifestyle factors on colorectal cancer risk, which is now the third most common cancer in men, and second most common cancer in women.
Lifestyle factors have been shown to play an important role in the development of colorectal cancer. This is supported by the fact that almost 55% of colorectal cancers occur in more developed countries, where there is increased sedentary lifestyle, and greater access to and consumption of unhealthy foods. Our previous report on colorectal cancer and lifestyle factors summarised a study assessing the effect of physical activity on risk of colorectal cancer. However, another recent study has investigated the combined effect of five healthy lifestyle factors on risk of developing colorectal cancer.
Previous studies have demonstrated that diet, BMI, smoking, and alcohol consumption all increase the risk of developing colorectal cancer. The authors of the current study state that while the individual roles of these factors have been studied, the combined effects have not. For this reason, the aim of this study was to develop a ‘healthy lifestyle index’ which is comprised of five different lifestyle factors: healthy weight, physical activity, non-smoking, limited alcohol consumption, and healthy diet. The authors then investigated the association of the healthy lifestyle index with the incidence of colorectal cancer.
A total of 521,330 men and women were recruited for the study between January 1992 and December 2000. The participants were aged between 25 and 70 years old, and recruited from 23 centres across 10 European countries. In total, the study population was made up of 3,759 colorectal cancer cases (2,369 colon and 1390 rectal) and 343,478 non-cases. The participants filled out questionnaires, answering a range of medical, dietary, and lifestyle questions.
The study reported that the participants who were found to have a higher healthy lifestyle index were more likely to be women with a higher educational level. The study also reported that each healthy lifestyle factor was linked with a reduction in risk of colorectal cancer. These results remained true when taking into account age, gender, and educational status. They also reported that each additional healthy lifestyle factor was associated with a 12% lower risk of colorectal cancer. The study concluded that a combination of the five lifestyle factors was associated with a reduced risk of colorectal cancer. They therefore suggest that these lifestyle factors should be the focus of prevention strategies to improve the rate of colorectal cancer development.
Overall, the results of the study suggest that the development of colorectal cancer is likely due to a combination of factors that are associated with ‘westernisation’ leading to un healthy diet and lifestyle, and that a combination of changes associated with a greater degree of healthy living can dramatically reduce the risk of colorectal cancer.
Aleksandrova, K, Pischon, T, Jenab, M, Bueno-de-Mesquita, HB, Fedirko, V, Norat, T, Romaguera, D, Knüppel, S, Boutron-Ruault, MC, Dossus, L, Dartois, L, Kaaks, R, Li, K, Tjønneland, A, Overvad, K, Ramón Quirós, J, Buckland, G, José Sánchez, M, Dorronsoro, M, Chirlaque, MD, Barricarte, A, Khaw, KT, Wareham, NJ, Bradbury, KE, Trichopoulou, A, Lagiou, P, Trichopoulos, D, Palli, D, Krogh, V, Tumino, R, Naccarati, A, Panico, S, Siersema, PD, Peeters, PHM, Ljuslinder, I, Johansson, I, Ericson, U, Ohlsson, B, Weiderpass, E, Skeie, G, BenjaminsenBorch, K, Rinaldi, S, Romieu, I, Kong, J, Gunter, MJ, Ward, HA, Riboli, E, Boeing, H.“Combined impact of healthy lifestyle factors on colorectal cancer: a large European cohort study”BMC Medicine 2014, 12:168
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Written by Deborah Tallarigo, PhD