It’s no secret that genetic, hormonal and environmental factors all seem to play a role in breast cancer. When it comes to alcohol and breast cancer risk specifically, a May 2016 study provides even more insight suggesting that lifestyle factors — including how much alcohol a woman drinks — really matters.
Danish researchers published a study in the British Journal of Medicine providing even more detail of the alcohol and breast cancer risk connection. Analyzing women’s change in alcohol consumption over a five-year period, Danish researchers found that women who increased the amount of alcohol they drank over a five-year period faced a higher risk of breast cancer.
For instance, women who drank two more alcohol drinks a day over five years saw a 30 percent increased risk of breast cancer compared to women with stable alcohol intake. That same study found a 20 percent lower risk of heart disease in woman who drank more. However, the study authors noted there are other ways to lower heart disease risk without increasing your breast cancer risk from drinking alcohol. (2, 3)
Alcohol and Breast Cancer Risk Findings
Research consistently shows that drinking alcoholic beverages increases a woman’s risk of hormone-receptor-positive breast cancer. Alcohol not only damages DNA in cells, but it also triggers higher levels of estrogen and other hormones linked to hormone-receptor-positive breast cancer. Compared to women who don’t drink at all, women who have three alcoholic drinks per week have a 15 percent higher risk of breast cancer. The estimated alcohol and breast cancer risk increases another 10 percent for each additional drink women regularly have each day, according to breastcancer.org.
Here are more important alcohol and breast cancer risk findings:
- A large meta-analysis looking at the relationship between alcohol and breast cancer risk in women also found that women who drank about three alcoholic drinks a week experienced a moderate increase in breast cancer risk. (4)
- A 2009 study found that drinking just three to four alcoholic beverages a week increases a women’s risk of breast cancer recurrence in women who’d been diagnosed with early-stage breast cancer. (5)
- In March 2016, University of Houston researchers found that alcohol not only fuels estrogen that drives the growth of breast cancer cells, but it also diminishes the effects of popular cancer drug Tamoxifen, a widely-used estrogen-blocking drug used to treat many breast cancers. (6)
- The U.S. Centers for Disease Control and Prevention advises women to drink no more than one drink a day. (7) If you drink less than this, don’t increase the amount of alcohol you drink.
Defining a “Drink”
When considering all of this research investigating alcohol and breast cancer risk, it’s important to understand what a “drink” actually means. For instance, drinking one dirty martini is very different than drinking a glass of beer or wine. Each may seem like a single drink, but a dirty martini typically contains about 6 ounces of vodka. That means your single martini, for instance, would actually be considered four drinks.
Researchers often use the following National Institute on Alcohol Abuse and Alcoholism guidelines to define what constitutes as one drink, which is about 0.6 ounces of pure alcohol:
• 12 ounces of beer or hard cider (3 to 7 percent alcohol)
• 8 ounces of malt liquor
• 5 ounces of wine
• 1.5 ounces or a “shot” of 80-proof liquor
Keep in mind that a craft beer with a high alcohol percentage served in a common 16-ounce pint glass could actually be more on par with drinking two 12-ounce bottles of beer with a more standard alcohol percentage of 3 to 7 percent alcohol. (8) And when you’re sipping on something like red wine, be aware of how many ounces the glass is really holding.
Women who drink up to one drink a day and men who drink up to two drinks a day are considered moderate drinkers. Women having four or more drinks on any day or a total of eight or more drinks a week are considered high-risk, excessive drinkers. (For men, drinking more than five drinks on any day or 15 or more drinks a week is considered high-risk, excessive drinking.) (9)
Other Ways to Lower Your Risk of Breast Cancer
With breast cancer cases expected to increase 50 percent by 2030, it’s important to not only consider alcohol and breast cancer risk, but take steps to lower your risk through other lifestyle improvements. (10) The important takeaway is that there are many things you can do lower your breast cancer risk in a meaningful way. Aside from lowering the levels of alcohol you drink, here are other ways to get started:
- Fruits and veggies are loaded with cancer-fighting compounds — Interesting, a 2016 study found that when girls eat more fruit during adolescence (at least 2.9 servings a day), they enjoy a 25 percent lower risk of developing breast cancer later in life compared to girls who eat the lowest levels of fruit during adolescence (less than a serving a day). (11, 12) Just be sure to choose organic when possible, since some fruits and veggies on the dirty dozen list harbor pesticides linked to cancer.
- Eat organic, fresh foods as much as possible — Avoid canned foods and drinks. Most contain toxic BPA, also known as bisphenol A, a harmful chemical linked to hormone disruption and breast cancer. (13)
- Avoid the heavy metal cadmium — It’s found in cigarettes smoke and linked to an increased risk of breast cancer. (14, 15) Cadmium is a common food contaminant most often found in shellfish, liver and kidney meats.
- Exercise — Strenuous exercise for 4+ hours a week can help lower your risk of breast cancer. Exercises can also help keep you out of the overweight/obese category, which is another risk factor for breast cancer in woman who have reached menopause. (16)
Final Thoughts on Alcohol and Breast Cancer Risk
It’s clear that alcohol and breast cancer risk are related, but it may be unrealistic for some women to completely give up all alcoholic drinks for the rest of their lives. The science suggests that increasing the amount of alcohol you drink in midlife increases your risk. Other large research studies found that drinking three drinks or more a week moderately increases risk. In other words, you don’t have to be a binge drinker to experience a significant increase in risk.
Having a glass of red wine now and then can provide you with a healthy dose of resveratrol, a potent antioxidant shown to expand your lifespan and aid in weight loss. However, it’s important to remember that alcohol is a neurotoxin that also puts unnecessary stress on your liver. You can easily get those same benefits from blueberries and supplements, so don’t rely on even occasional red wine as your sole source of resveratrol.