Association of lifestyle and environmental factors with the risk of cancer

It has been well established that certain lifestyle habits relate to the risk of certain cancers (e.g., smoking and lung cancer). In a well-done analysis, the authors estimate the proportion of cancer in the population associated with a variety of lifestyle and environmental factors. They find that smoking has, by far, the largest effect on the risk of cancer, with 19.4% of cancer cases in the UK attributable to tobacco use. A poor diet (less intake of fruits and vegetables and fibre and greater intake of meat and salt), obesity, and alcohol are the next most important factors that relate to cancer, with alcohol being calculated to relate to 4.0% of cancer cases in the UK.

Forum reviewers considered this to be a well-done paper that used epidemiologic methods that are preferable to those used in some previous such analyses. Generally, they disagreed with the authors that no alcohol consumption was the theoretical "optimum exposure level," as the risk of certain cancers seems to increase primarily from heavy drinking. Further, they found reason to believe that the purported effects related to diet may have been over-estimated.

Nevertheless, this paper provides considerable new information on lifestyle and environmental factors that may relate to the risk of cancer. It puts into perspective the importance of targeting certain behaviours for the potential reduction in the risk of cancer.