Making multiple changes to lifestyle factors can reduce risk of developing colorectal cancer

Intestines (cropped)Deborah Gilbert from Bowel & Cancer Research and Mohamed A Thaha the National Centre for Bowel Research and Surgical Innovation at Queen Mary University of London discuss a recent article published in BMC Medicine in which it has been found that adoption of a combination of five key healthy behaviors is associated with a reduction in the risk of developing bowel cancer.

Colorectal cancer (CRC) is the third most prevalent cancer and the second most common cancer killer. In recent decades, although cancer care has improved and more people survive longer, many CRC cases are still diagnosed at a late stage, when survival is much less likely. For this reason, much attention is now focused on preventing CRCs using strategies including population based screening and promoting a ‘healthy lifestyle’.

The increasing frequency of CRC in a westernised population has led to the premise that lifestyle factors play a major role in their development. Several factors are thought to be protective in terms of developing CRC; these include physical activity and increased intakes of dietary fibre, fish, nuts, dairy products, fruits and vegetables. Evidence has shown that other factors, including weight and obesity, waist circumference, smoking, alcohol consumption, and red and processed meat intakes increase the risk of CRC.

Lowering cancer risk through eating well and exercising, reducing alcohol intake and stopping smoking are well-known health messages that form the cornerstone of many cancer prevention public health policy campaigns. The ‘five-a-day’ message which specifically gives the health benefit of eating more fruits and vegetables (fibre) to reduce the incidence of cancer and heart disease is perhaps the best known.

The role of these individual lifestyle factors in the development of CRC is clear. However, in real life, seldom do these factors happen in isolation yet little is known about how the combination of these lifestyle factors influence the development of CRC. Dr Aleksandrova and her European team in their large research study published in BMC Medicine have attempted to examine just that.

The study recruited some 347,237men and women from 10 European countries who were part of the the European Prospective Investigation into Cancer and Nutrition (EPIC) study. EPIC is one of the largest cohort studies in the world, and investigated the relationship between diet, nutritional status, lifestyle and environmental factors, and the incidence of cancer. Men and women between 25 and 70 years of age provided dietary and lifestyle information and were followed up for a median of 12 years. Investigators developed a “healthy lifestyle index” (HLI) composed of five modifiable lifestyle factors – weight, physical activity, non-smoking, limited alcohol consumption and diet. They studied the association of HLI with the CRC incidence.

More than half of participants in the study had BMI and waist circumference within recommended range, had never smoked, had alcohol intake within the recommended limits, and followed a healthy diet. Amongst the study population 3,759 new cases of CRC were identified. Each healthy lifestyle factor was associated with a reduction in CRC risk when analysed individually, and each additional healthy lifestyle factor was associated with a 12% lower risk of CRC. Significantly, 16% of these new CRC cases were seen as due to non-adherence to a combination of all five healthy lifestyle behaviours, 22% of which occurred in men and 11% in women. The findings of this study support the argument that any prevention strategies for CRC should focus on multiple lifestyle factors rather than single factors in isolation for maximum benefit.

Bowel & Cancer Research, as its names suggests, is a medical research funder. The charity, registered in the UK, has a mission to save and change lives – to increase the numbers of people who survive bowel cancer and to improve the quality of life of others who live with chronic conditions such as inflammatory bowel disease.

The charity places a high value on promoting actions that provide people with the tools to manage their own bowel cancer risk, for example screening for early detection. Recognising the key contributory role of lifestyle factors in the development of cancer, the charity promotes healthy lifestyle messages and sees this as an important part of developing a “toolkit” for the general public. We run campaigns to promote a healthy lifestyle and underpin these with an annual “attitudes” survey which aims to assess to what extent the public are hearing key messages.

Bowel & Cancer Research welcomes this study and intends to take the information from the present study and use it to inform accessible health campaigns with which the public can readily engage – to save and change lives.

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