Alcohol consumption and risk of colon cancer

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A study based on more than 87,000 women and 47,000 men in the Nurses' Health Study and the Health Professionals Follow-up Study, looks at whether there is a link between colon cancer and alcohol, and if so at what level of consumption, and the importance of a family history of the disease. A total of 1,801 cases of colon cancer were diagnosed during follow-up from 1980 onwards.

The authors results found that subjects with a family history, whose average alcohol intake was 30 or more grams per day (about 2 ½ typical drinks by US standards or 4 UK units) had an increase in their risk of colon cancer. Those at greatest risk also ate the most red meat, smoked the most, and had the lowest intake of folate (suggesting they ate fewer green vegetables and cereals. Hence, these people have the most unhealthy lifestyles in general of the populations studied. There was not a significant association between alcohol consumption and colon cancer among subjects without a positive family history in this study.

Forum reviewers were concerned that the pattern of drinking (regularly or binge drinking) was not assessed, and that there was not a consistent increase in risk of cancer with greater alcohol intake found. Further, adequate folate intake was found to lower risk, with the highest risk for subjects with a positive family history of colon cancer, low levels of folate, and in the highest category of alcohol consumption, indicating the importance of other lifestyle facts such as a healthy diet.

The present study provides some support for an association between higher levels of alcohol intake and the risk of colon cancer among subjects with a positive family history of such cancer. It should be noted that there have been changes in the guidelines for screening for colon cancer (by endoscopy, with removal of pre-malignant tumours) and other preventive measures for people with a positive family history of colon cancer, making it hard to draw conclusions on data for colon cancer that is 30 years old. The new recommendation for screening frequency and age at initiation of screening are so different now. At least some of these cases would probably have been prevented if managed according to current guidelines. Such measures could modify the effects of all risk factors for colon cancer in future analyses.