Even light alcoholic drinking can increase a woman’s risk of breast cancer, finds a new review of the research, with more alcohol leading to higher risk. The review aligns with the findings of AICR’s report on breast cancer prevention, adding to the understanding of alcohol intake and cancer risk.
AICR research shows that even small amounts of alcohol regularly increases women’s risk of breast cancer, both pre- and postmenopausal.
Study authors reviewed 15 relevant meta-analyses on the topic published since January 1, 2000, finding almost all showed a consistent dose-response link to increased breast cancer risk starting at the lowest category. Light drinking categories varied slightly depending upon the study. One drink has 14 grams of ethanol or alcohol. In one study, light drinking was categorized as 3 to 6 drinks per week, converting to 10 grams of ethanol a day. Another study categorized light drinkers as having about a half to one drink per day, 5 to 14.9 grams of ethanol per day.
Postdiagnosis alcohol consumption was not related to the recurrence of breast cancer or to breast cancer-specific survival.
The review then investigated cell and animal studies for possible mechanisms. These include: ethanol metabolism can lead to reactive molecules containing oxygen (reactive oxygen species or ROS), which can damage DNA; alcohol can increase levels of estrogen and other hormones related to breast cancer development; and alcohol may inhibit folate absorption, which may increase risk.
Using data on alcohol intake and cancer incidence, study authors calculated that an estimated 144,000 breast cancer cases and 38,000 breast cancer deaths worldwide in 2012 were due to alcohol. Approximately 18 percent of these cases and deaths affected women who were light drinkers, they estimate. Here, they used the definition of light drinker as having less than 1.5 alcoholic drinks per day (less than 21 grams of alcohol per day), basing that on the World Health Organization’s
alcohol consumption categories.
There are several caveats to this review, such as possibly misclassifying the women level of drinking and those who abstain from drinking being in better health overall.
For more on alcohol and other breast cancer risk factors visit here.
The authors declare no support of conflicts of interest.
Source: Kevin D. Shield, Isabelle Soerjomataram, Jürgen Rehm. Alcohol Use and Breast Cancer: A Critical Review. Alcoholism: Clinical and Experimental Research, 2016; 40 (6): Alcoholism: Clinical and Experimental Research. V40, Issue 6, 1166–1181, June 2016