Following prevention guidelines may reduce risk of cancer by up to two thirds

Eating a healthier diet, increasing physical exercise, reducing alcohol consumption, and stopping smoking are all modifiable lifestyle choices that could help prevent up to two thirds of cancer suggests new research.

Organisations such as the American Cancer Society (ACS) and the World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) have set recommendations on diet and physical activity as part of their cancer prevention strategy.

New research analysed 12 prospective cohort studies published within the last ten years to look at the association between following these guidelines and cancer incidence and mortality. The research, which looked at mostly Caucasian participants aged from 25 to 79, compared studies with high levels of adherence to the guidelines with lower levels of adherence. 

Although levels of adherence to the guidelines varied across the studies, the team reported that consistent patterns emerged, with results showing adherence to cancer prevention guidelines was associated with a 10 to 45% reduction in rates of all cancer incidence and a 14 to 61% reduction in rates of all cancer mortality.

Other findings to come from the analysis included consistent reductions in the incidence of breast cancer (19 to 60%), endometrial cancer (23 to 60%), and colorectal cancer (27 to 52%) in both men and women, although the results showed no significant associations with the incidence of ovarian or prostate cancer, and associations with lung cancer varied depended on the study.

Healthy behaviours have extra added benefits 

The team also found that those with a high level of adherence to the guidelines, following more of the cancer prevention recommendations, benefited from an even bigger reduction in their risk of developing or dying from the disease. For example, in one study, women who followed at least five of the recommendations were 60 % less likely to develop breast cancer than those who met no recommendations at all, and for each additional recommendation met, the risk of breast cancer was reduced by a further 11 %.

Speaking on the findings, Kohler, one of the authors of the study, commented that "Behaviours such as poor diet choices, physical inactivity, excess alcohol consumption and unhealthy body weight could account for more than 20 % of cancer cases, and could, therefore, be prevented with lifestyle modifications."   She also added that when smoking is taken into account, these modifiable lifestyle choices are believed to be factors in two-thirds of US cancer deaths.

However Kohler also noted that adhering to the guidelines did not eliminate the risk of developing or dying from cancer completely, with family history and environmental factors also playing a role, "However, following these recommendations will lead to healthier lives overall and, in turn, reduce the risk for many major diseases." Kohler also added that the results of the review suggest that doctors and public health officials should continue to emphasise the importance of these cancer prevention recommendations and a healthier lifestyle to patients.