Lighter Drinking Connected to Breast Cancer

People who drink heavily and frequently are making a lifestyle choice that puts them at risk for a number of conditions, including cirrhosis, dementia, and cardiovascular disease. But those of us who enjoy a glass of wine with dinner every night or a couple of beers or cocktails while out socializing a few times a week hardly fall into the category of hard drinkers. However, that doesn’t mean you are safe, especially if you are a woman. New research suggests that even women with lighter alcohol consumption may be in increased danger of developing breast cancer.

The study, which was conducted at Harvard’s T.H. Chan School of Public Health in Boston, Massachusetts, found that breast cancer risk is higher in women who are considered light to moderate users of alcohol than it is in their peers who abstain from drinking.¹ Schumaker, Erin. “Moderate Alcohol Use Linked With Breast Cancer In Women.” Huffington Post. 20 August 2015. Accessed 26 August 2015. http://www.huffingtonpost.com/entry/moderate-drinking-linked-to-breast-cancer_55d4a4e0e4b07addcb44e7b8 The analysis was based on data from two major studies with large population samples totaling more than 100,000 subjects: the original cohort of the Nurses’ Health Study, with female participants involved in 1980, and the Health Professionals Follow-Up Study, which ran from 1986 through 2010 and concentrated on males.

Based on the data collected in these two trials, the scientists involved in the current research were able to extrapolate information on the health and drinking habits of both men and women. They focused on determining whether there were any links between alcohol intake and various types of cancer. Light to moderate drinking was defined as approximately one drink per day for women and approximately two drinks per day for men. Women who were light to moderate drinkers were found to have a 13 percent increase in alcohol-related cancers. This includes breast, lung, colon, pancreatic, liver, oral, pharyngeal, laryngeal, and esophageal cancers. However, in the current study, the elevated rate was primarily seen in cases of breast cancer–and primarily in women.

There were no links shown to higher cancer risks in men who were moderate drinkers, with one important exception. If they were smokers or even former smokers, their chances of developing an alcohol-related cancer went up. And both men and women who were heavy alcohol users as well as current or former smokers were found to have an elevated risk of alcohol-related cancers as well.

The results that pertain to light and moderate drinkers differ somewhat from other recent research that discovered an association between alcohol intake and a variety of cancers.² Bagnardi, Vincenzo; et al. “Alcohol Consumption and the Risk of Cancer: A Meta-Analysis.” National Institute on Alcohol Abuse and Alcoholism. Accessed 27 August 2015. http://pubs.niaaa.nih.gov/publications/arh25-4/263-270.htm But even if the evidence was not quite as clear in this study as in earlier ones, the fact that one type of cancer was more prevalent among drinkers still reminds us of the fact that regular drinking has negative consequences for our health. Both men and women–even those who have never smoked–can still face an elevated risk of cancer. So even lighter drinkers can’t discount the effects alcohol may have over time, and that’s particularly true for individuals with a family history of any type of alcohol-related cancer or personal smoking habit.

The association between breast cancer and even just one drink a day certainly should not be ignored. However, it is important to note that alcohol may not be the primary trigger here, but rather, a secondary one. As Jon Barron explained a number of years ago, alcohol’s connection to breast cancer likely lies in its tendency to exacerbate hormone imbalances. In fact, a 2000 study at Queen Margaret University College in Edinburgh, United Kingdom found that moderate alcohol consumption produces a rise in estrogen levels in women.³ Gill, Jan. “The Effects of Moderate Alcohol Consumption on Female Hormone Levels and Reproductive Function.” Alcohol and Alcoholism. 1 September 2000. Accessed 27 August 2015. http://alcalc.oxfordjournals.org/content/35/5/417.full

Breast cancer is the single most common form of the disease in the United States, finally surpassing lung cancer with more than 234,000 new cases expected in 2015 alone. And 99% of those cases are women.⁴ “Statistics for Different Kinds of Cancer.” CDC August 20, 2015 (Accessed 28 Aug 2015.) http://www.cdc.gov/cancer/dcpc/data/types.htm So if giving up alcohol or cutting back on your consumption might help prevent you from developing breast cancer, it would certainly be worthwhile.