Alcohol consumption up to one glass per day is not associated with risk of most types of cancer. That is the conclusion of a meta-analysis that was recently published in the scientific journal Cancer Research and Treatment.

Increased and decreased risk
The meta-analysis¹ looks at the effect of light and moderate drinking on more than 20 types of cancer. Alcohol consumption up to one glass per day is not associated with risk of most types of cancer, except for breast cancer among women and colorectal cancer among men where light alcohol drinking (<1 drink/day (±12.5g)) respectively increases the risk with 9% (for breast cancer), and with 6% (for colorectal cancer in men). For both men and women, the risk of lung cancer and thyroid cancer decreases (with 9% and 11% respectively) when drinking up to one glass of alcohol per day.

Mechanism
The researchers also describe the possible mechanisms behind the association between light alcohol consumption and breast and colorectal cancer. However, it remains unclear why these carcinogenic effects of alcohol are not related to other types of cancer.
The preventive effect of alcohol on lung cancer could be caused by anti-inflammatory, antioxidant, and anti-carcinogenic effects. But it remains unclear why these effects would be specific for lung cancer.

In perspective
Previously we wrote about studies that found the same effects for breast cancer, lung cancer and thyroid cancer (meta-analysis). The association between alcohol and colorectal cancer was previously confirmed in a meta-analysis².
The researchers of the meta-analysis indicate that the newly revised 2015 European Code against Cancer was based on critical flaws in the interpretation and citation of previous meta-analyses. Therefore, the researchers suggest that the current recommendation in the code (“Not drinking is better for cancer prevention”) should be adapted to “Not drinking is better in order to prevent breast cancer in women and colorectal cancer in men”.

References
1. Y- J. Choi, Myung, S. – K., and Lee, J. – H., Light Alcohol Drinking and Risk of Cancer: A Meta-analysis of Cohort Studies., Cancer Research and Treatment, 2017.
2. Wang, Duan, H., Yang, H., and Lin, J., A pooled analysis of alcohol intake and colorectal cancer, International Journal of Clinical and Experimental Medicine, vol. 8, nr. 5, pp. 6878 – 6889, 2015.