LIFESTYLE changes involving smoking, body weight, drinking, and physical activity may reduce the risk of developing colorectal cancer (CRC), according to new data. While previous studies had shown a link between lifestyle factors and cancer, as well as an association between smoking cessation and a reduced risk of CRC or weight gain and an increased risk of CRC, there was no specific research yet on the link between the risk of CRC and other lifestyle factors.
The researchers followed 2995,865 people between 35–70 years who participated in the European Prospective Investigation into Cancer (EPIC) for a median of 7.8 years. A healthy lifestyle index (HLI) score was calculated, taking into account alcohol consumption, smoking status, physical activity, and BMI. The HLI scores ranged from 0–16. The mean score was 10.04 at baseline but had dropped to 9.95 at follow-up. Researchers noted that the scores in males were more favourable than in females, and that the link between the score and CRC risk was only statistically significant in males. An increase in HLI score was linked to a 3% lower risk of developing CRC.
Furthermore, improving from an unfavourable lifestyle (with a score from 0–9) to a favourable lifestyle (with a score from 12–16), was linked to a 23% lower risk of developing CRC, compared to those who did not change. On the other hand, a change from a favourable lifestyle to an unfavourable lifestyle was linked to a 34% higher risk of developing CRC. Data also showed that changes in BMI could be associated with CRC risk, decreasing alcohol consumption lowered CRC risk in those aged 55 years or younger, and increasing physic al activity lowered the risk of proximal colon cancer. Reduction in smoking was associated with an increased risk of CRC; however, researchers noted this may be due to inverse causation, as people may have stopped smoking when experiencing early symptoms of CRC.
One of the limitations of the study was that information on diet was only collected at baseline and, therefore, could not be measured; however, author Edoardo Botteri, Cancer Registry of Norway, Oslo, Norway, stated: “This is a clear message that practicing clinicians and gastroenterologists could give to their patients and to CRC screening participants to improve CRC prevention.” Further research could help design intervention studies in order to prevent CRC.