Researchers examined data from 845 people with colorectal cancer to determine if smoking and drinking may have influenced their chances of developing the disease. Their findings, published in the journal Epidemiology, were pretty straightforward.
Results of the Cigarettes and Alcohol Study
Consuming more than seven alcoholic drinks a week increased the risk of colorectal cancer by 72 percent. Smokers were more likely to develop rectal cancer, with risk increasing as the number of cigarettes increased (from 43 percent higher risk for light smokers to 164 percent higher risk for heavy smokers).
For more detailed information regarding the role cigarettes and alcohol play in colon cancer development, please read Smoking and Colorectal Cancer Risk and Does Alcohol Increase Colorectal Cancer Risk?.
More Research on Cigarettes and Colorectal Cancer Risk:- No Such Thing as a Safe Cigarette... Smoker
- Smoking Increases Risk for Carriers of HNPCC Gene
- Vitamins Aren't Always Good for You
- Smoking Causes Genetic Damage Linked to Colon Cancer
- Wine May Lower Risk of Colorectal Cancer
- More Evidence that Alcohol Increases Colorectal Cancer Risk
- Colon Cancer Smackdown: Spirits vs. Wine
- Vitamins Aren't Always Good for You
- Alcohol Found to Increase Rectal Cancer Risk
Source: Tsong, W. and Koh, W. "Cigarettes and Alcohol in Relation to Colorectal Cancer: The Singapore Chinese Health Study." British Journal of Cancer 96 (2007): 821-827. Accessed 10 Mar. 2007.

