Alcohol and Breast Cancer Risk
Listen to the episode to Dr. Avonne Connor explain:
how much alcohol affects breast cancer risk
why alcohol as a breast cancer risk factor is so emotional
why binge drinking is so harmful
why drinking during treatment isn’t a good idea
steps people can take if they want to reduce or quit drinking
Dr. Avonne Connor is assistant professor of epidemiology at Johns Hopkins University. Much of Dr. Connor’s research focuses on cancer health disparities in women, especially cancer risk factors that people have some control over, such as drinking alcohol, weight, exercise, and smoking.
— Last updated on June 29, 2022, 2:57 PM
Jamie DePolo: Hello, as always, thanks for listening. Our guest today is Avonne Connor, assistant professor of epidemiology at Johns Hopkins University. Much of Dr. Connor’s research focuses on cancer health disparities in women, especially cancer risk factors that people have some control over, such as drinking alcohol, weight, exercise, and smoking. She joins us today to talk about a topic that always seems to be controversial: alcohol and breast cancer risk. Dr. Connor, welcome to the podcast.
Dr. Avonne Connor: Thank you, Jamie, for this opportunity to discuss this important topic.
Jamie DePolo: So, I have read studies that show that even light drinking — which I believe is defined as less than one drink per day — increases breast cancer risk. But I really can’t think of any other risk factor for breast cancer that is so controversial and seems so emotional. And it also seems like a lot of people really don’t know that drinking alcohol is linked to an increase in breast cancer risk. So, to start us off, could you give us your opinion on why drinking alcohol is just so fraught and so emotional, and why do you think people don’t know about this link to increased breast cancer risk? Do you think they’re just kind of avoiding it because they really want that glass of wine at the end of the day?
Dr. Avonne Connor: Well, you make some great points, Jamie. And as you mentioned, some people are either unaware about the effects of alcohol on breast cancer risk, and some just might avoid this news or association altogether.
So, as you mentioned, drinking even small amounts of alcohol is linked with an increased risk of breast cancer in women, and this association is most likely due to changes in estrogen in the body that are caused by alcohol consumption. So, avoiding or even decreasing your intake of alcohol may be an important way for many women to lower their risk of breast cancer.
I think this is a controversial topic due to the fact that we have received different research news about the effects of alcohol with other health outcomes, more specifically heart disease. Moderate drinking, which is one drink a day for women, appears to protect some people against heart disease.
I think this is also important to understand the perspective of women who drink alcohol regularly. So, women who drink for many reasons are some of the same reasons that men drink, actually: to relax, to gain confidence in social situations, to celebrate, to sleep better at night, or to release stress. Therefore, I think it’s important that we address some of the root causes of why women are drinking in the first place, to know that there are these risks associated with alcohol use, and to increase the awareness of this potential risk for breast cancer with alcohol consumption.
Jamie DePolo: Okay, thank you. Now, I have read some conflicting study results, and I know it’s hard because there are other things involved, but do we really know how much alcohol affects breast cancer risk? Because people have asked me this like, “Okay, well, if I only have one drink a week as opposed to three drinks a week, how much is my risk going down?” Like, are we there yet? Do we know that yet?
Dr. Avonne Connor: That’s a great question. It’s very common for epidemiologists, too, because this is what we study.
Jamie DePolo: Right.
Dr. Avonne Connor: So, there have been numerous epidemiological studies conducted to investigate this association. And one of the most recently published studies in the Journal of the American Medical Association, also known as JAMA, is that these researchers found that consuming as few as three to six alcoholic beverages a week may be linked to a 15% increased risk of breast cancer. So, that’s our latest news that we have in our epidemiological literature.
Jamie DePolo: Okay. And we really — I’m assuming the research hasn’t been done yet — so, if that was three to six drinks per week, if somebody cut that down to one, we wouldn’t know, say, if that’s a 15% increase of risk with three to six. If I only have one, does that mean my risk only goes up 5%? Is that even feasible to calculate?
Dr. Avonne Connor: I think that is an interesting question, because you have to go into the methods of how the researchers actually asked about alcohol consumption. So, I’m sure it was probably drinks per day. So, this quantification that they figured out, three to six, was probably the significant threshold of what they found to be significantly statistic. So, knowing how much one drink impacts your risk per day might be more of a fine-tuned method that the researchers did not get to. Or, actually, maybe they wanted to focus in on this more — this category of three to six — because of the sample size that they had or for other reasons in their method.
Jamie DePolo: Okay. Okay, I see. So, maybe in that particular study most of the women were drinking three to six drinks per week, so that may be why they focused on that. We don’t know.
Dr. Avonne Connor: Right. Right. That’s a good point.
Jamie DePolo: Okay, got it. Got it. So, you touched on this a little bit in your first answer — you know, we were told for a long time drinking red wine helps the heart, it’s actually good for you. And I cannot tell you how many of my friends said, “Oh, I’m drinking to my health!” But, I feel like I’ve read studies sort of disproving that — that it’s not really this great thing for heart health. So, could you talk a little bit about that? Is my impression correct or has other research shown that it really is beneficial? What do we know right now?
Dr. Avonne Connor: Sure. So, the health effects of red wine have been debated for some time now, as you mentioned. Studies have repeatedly shown that moderate red wine consumption seems to lower risk of several diseases, which include heart disease. However, there is this fine line between moderate drinking and excessive intake. So, you know, having that one glass — if you change it to two or three per day will not give you that significant health benefit if you were just drinking that one, which is considered moderate drinking.
Consuming moderate amounts of red wine has been shown to have health benefits. The grapes that are used in red wine of course are rich in antioxidants, which have many health benefits including fighting inflammation and blood clotting, which are important in heart disease. And then you also have these polyphenols that amount to only a small fraction of the wine’s total content, but are particularly interesting for the cardiologists because they have these potential biological and cardioprotective properties.
So, some studies have shown that drinking one to two glasses of red wine each day may lower the risk of heart disease and stroke, but having these high amounts increases their risk. So, I think that’s where the mixed messaging comes in, and many epidemiological investigations have supported these findings of red wine. And others have also found significant results with beer and spirits, which may suggest that it’s not just red wine, it’s just any type of alcohol might decrease your risk of heart disease, in moderation, of course. A recent study, also by Harvard, found that moderate drinking is linked to lower risk of death from heart disease, and they think that this could be due to the alcohol’s ability to relieve stress in the brain.
So, altogether, there’s mixed results, but of course no one is recommending that you should have alcohol as a way to reduce your heart disease risk. So, I think that’s the main message. And alcohol has other harmful properties for other diseases, such as breast cancer and other cancers, and so just having alcohol to decrease your risk of heart disease isn’t the main focus of what we should be doing to protect our heart and other organs.
Jamie DePolo: Right. And it sounds like, too, from the studies you mentioned, more alcohol is definitely not better.
Dr. Avonne Connor: Exactly.
Jamie DePolo: The benefits are not going up with the second glass.
Dr. Avonne Connor: Yes. So, that’s also is what we call a dose response. So, intuitively we think, “Oh, the more the better. If a little bit’s good, then maybe a lot would be better.” But that’s not the case with alcohol.
Jamie DePolo: Okay. It’s not the case with a lot of things.
Dr. Avonne Connor: Yes.
Jamie DePolo: I’m not really sure where that adage came from, but you’re right, it does seem to be very popular!
So, besides the flavor — which I know people talk about, like pairing a really nice wine with a delicious meal. A lot of people drink alcohol because, as you said, too, it’s celebratory. Like, the first thing if somebody gets a promotion, somebody has something great happen to them, what’s the response? “Let’s go out for drinks! Let’s have a glass of champagne and toast the accomplishment.”
And for somebody who has been diagnosed with breast cancer — or really any cancer, I think — they may feel judged or blamed if they go out for a drink with friends. Or, they may feel blamed for drinks they had before they were diagnosed, and breast cancer wasn’t even on their radar. So, do you have any advice for those folks from your view as an epidemiologist? Like, part of me thinks you can only control so much and whether you had that glass of wine with your friend 5 years ago — you know, are we really looking at a cause-and-effect relationship there?
Dr. Avonne Connor: Yes, and that’s a great point. I would tell them that we are all human and not to feel judged or blamed. And there are many modifiable lifestyle factors that are associated with breast cancer, or with any cancer, for that matter. We talk about things that are modifiable, which could be obesity; if you’re physically active or not; other lifestyle choices with diet. So, no one can pinpoint which specific factor contributes the most to whatever risk that you had for having that disease. So, my suggestion is to do what you feel is best for you and enjoy yourself in those social situations, but of course with moderation.
Jamie DePolo: Okay. Moderation is key always, right?
Dr. Avonne Connor: Yes.
Jamie DePolo: And I’m curious, too, as you were talking there … there are a few modifiable risks, and I guess what I’m wondering — and this may be a very hard question to answer, so I apologize in advance. We know that drinking alcohol increases risk, and we know that being overweight increases breast cancer risk, and we know that not exercising increases breast cancer risk. Has any study ranked those? So, say if somebody maintains a really good weight for their body size, for their height, and they exercise regularly, is it maybe possible that having one drink a week — easy for me to say — would have less of an effect on that person than somebody else who maybe is overweight and doesn’t exercise? Can they offset each other like that? I really don’t know.
Dr. Avonne Connor: They actually can. So, it’s kind of like the benefits-and-harms approach in equalling out — cancelling out — the harms with the benefits. So, yes, I totally agree. So, if you think about the ways to — something that we were all kind of probably doing during the pandemic, trying to lose your pandemic pounds. If you’re cutting down on your diet; let’s say you have a bad day and decide that you know you want to have that burger. If you go exercise that day, it does bring down some of that, you know, effects of eating whatever that was that you feel like was high calorie. So, the same effects with cancer risk, in my opinion. And we do have data showing the percentage of risk that each of these modifiable factors contribute to what we know about cancer.
So, it could be … so, what we said for women who are — it’s usually postmenopausal women — are at higher risk if they’re obese. So, if you are losing weight, and physically active, and you are maintaining a good diet, then it could be that, even though you’re obese, your inflammation levels aren’t as high because you’re exercising, so that reduces your risk. Your insulin levels aren’t as high, so that’s kind of bringing down that risk pattern for you to have breast cancer. So, there is a tradeoff of healthy alternatives, say, to complement things that you might feel aren’t as healthy. So, if you’re having wine, yes, be physically active. Take those walks. Maybe you should modify your diet some and eat less red meat or eat less high-calorie foods.
So, I think that it all does add up — if that’s what you were trying to get to — with thinking about how to reduce your risk and how to kind of modify certain lifestyle choices. To adapt to things that, “Yeah, I want to splurge this week and have a glass of wine when I go out with my friends to celebrate someone’s promotion.” Sure. So, maybe, “I’m not going to — I’ll eat a salad, instead of ordering my steak.” So, all these things add up over time, for sure.
Jamie DePolo: Okay. Yeah, great, that makes sense. That makes sense. And I kind of want to stick on the drinking socially topic.
Dr. Avonne Connor: Yes.
Jamie DePolo: Especially, this past pandemic year has been really tough for a lot of people. And, I’ve read studies showing drinking is up over the year because people were just sitting at home with nothing to do besides feel scared, anxious, depressed, all those kinds of things. So, I kind of have two questions for you. One was: Drinking in general was up, but also binge drinking, in particular, went up — and especially binge drinking by women, it seemed, went up during the pandemic. And so, if you could help us understand why binge drinking is worse. I have some ideas, but I’d rather hear it from the expert. And also, so, if someone, say, they binge drink over the weekend because they’re not working, but then they don’t drink at all for 2 or 3 weeks, is there that same, sort of, like, “leveling-out” effect or is binge drinking just bad all the time?
Dr. Avonne Connor: Yeah, I think this topic of pandemic drinking is very relevant, of course, because we’re still, technically still in the pandemic. And some people are still not working, or still finding jobs, and still dealing with pandemic stress. But, even before the pandemic, we’ve noticed a higher consumption of alcohol among women than previous years, and the pandemic has just kind of compounded on that situation. So, we have social media sites of, you know, they have memes of moms drinking to relieve their stress, and alcohol is now easier to obtain through delivery sites and apps. And so, it’s not surprising that we’re seeing this disproportionate effect of the pandemic on women’s alcohol use.
So, as you said, binge drinking. So, the rates of alcohol use, the heavy drinking — which is having four or more drinks on one occasion — and other related drinking disorders in women are on the rise during the pandemic. And so, we consider binge drinking if you’re having four or more drinks, for women, in about 2 hours, actually, that’s like hard binge drinking. That’s actually worse, because it can cause irregular heart rhythms and arrhythmias. So, it does have this cardio effect that we don’t have if you were just drinking a couple of glasses of wine during the week that would add up to, say, four glasses of wine over 4 days versus having four glasses of wine within 2-hour span. So, even if you do not have any alcohol during the week, you should not save all of your drinking for the weekend and overdo it.
Jamie DePolo: Got it. Okay, that’s, that’s very good to know. And, I guess the second question about pandemic drinking: As things are opening up, you know, restaurants are — you can now dine inside, there’s outside dining, people are starting to go to movies and concerts. People are really excited to start doing things with their friends that they haven’t been able to do for more than a year, and obviously one of those things is go out to a bar, go out to dinner. Do you think that this sort of excitement is going to keep drinking levels high because people are so excited to get out and do these things again? Because, I guess I was wondering, like — okay, as the pandemic sort of eases a bit, maybe drinking is going to go down because people feel like life’s returning a little bit more to normal. What do you see from your epidemiologist chair?
Dr. Avonne Connor: I agree with you. I think a lot of the people who have been changing their drinking habits due to the pandemic — because of stress, anxiety, isolation, for whatever reasons. I think once things go back to normal for their lives — meaning getting out of the house more, seeing your friends, going back to work — that sense of that regular routine. And not having, you know, sometimes nights of boredom, and just at home alone. I think that a lot of these risky drinking behaviors will eventually decrease and that people will be back in their routines — their social routines — and will feel safer and I guess more at less stress levels, basically, with having some sense of normalcy again.
Jamie DePolo: Okay. Okay. Now, I have seen this question several times on our Breastcancer.org discussion boards with people asking, “Is it okay to drink alcohol during treatment?” And I believe they were specifically talking about chemotherapy. Obviously, some women if they’ve been diagnosed with — or women and men — if they’ve been diagnosed with hormone-receptor-positive breast cancer, they may be taking anti-estrogen therapy for 5 to 10 years after the main treatment is over. So, I’m not thinking that so much, but I guess I’m wondering about chemotherapy or immunotherapy — do we have any research on that? Like, I just assume it’s not a good idea, but I don’t know.
Dr. Avonne Connor: There are medications that don’t mix well with alcohol that we know of, so that’s a good point to mention. If we’re thinking about hormone therapy and other oral medications that could be chemo-related, that you should speak with your doctor about. And, just in general though, alcohol can cause you to have some diminishing effects on your immune system — which aren’t long-lasting, but they make the body more susceptible to infection. So, if you’re drinking alcohol regularly, you might find that you might have more colds than people who don’t drink alcohol. Or, you might feel that you catch viruses more easily when you’re drinking on a regular basis compared to your friends who aren’t drinking as much as you.
So, my suggestion is to talk to your doctor if you like to have a drink while you’re still having treatment. And if you’re not sure about — drinking is a good remedy for just relaxing, or if it’s just having your wine at the end of the day, I would definitely consult with the doctor about that, if you’re under active treatment. And something also to consider is there are studies that have shown that alcohol increases your risk of recurrence. So, you should also consider that in thinking about drinking in moderation, even after you complete your treatment: How often you want to keep drinking once you’ve finished your treatment. And what your, I guess, your quality-of-life trajectory might be if you’re still drinking, and want to reduce your risk of recurrence as well.
Jamie DePolo: Okay, thank you. And that’s very interesting about alcohol sort of suppressing the immune system, because I know so many of the chemotherapy drugs do that as well.
Dr. Avonne Connor: Exactly.
Jamie DePolo: So, that could be, yeah, that could be kind of a double whammy there.
Dr. Avonne Connor: Right.
Jamie DePolo: Okay, good to know. Thank you. So, finally, if somebody wants to cut back or even quit drinking alcohol altogether, do you have any advice for them? Are there steps they could take? And, I guess I’m also wondering, from your viewpoint as well: Are there kind of some signs that maybe if somebody is thinking like, “Oh, I don’t know, maybe I need some help. Maybe I need some professional help. Maybe my drinking got a little bit out of hand during the pandemic.” So, that’s kind of a two-part question: What would you recommend if somebody wants to cut back? And then how does somebody know if they really need professional help to do it?
Dr. Avonne Connor: Well, as I mentioned, we all consume alcohol for different reasons. And if you’re wanting to relax or relieve stress, I would suggest finding other ways, such as yoga or meditation. I highly recommend walking daily. Walking helps you relax and increases your body’s levels of those feel-good endorphins, which in turn can lower your stress and anxiety. And, as a bonus you get the other health benefits from walking, such as your heart health by decreasing heart disease risk factors, such as high blood pressure and high cholesterol. And also, the American Cancer Society has found that 7 hours per week may reduce your odds of developing breast cancer after menopause by up to 14%, and you also might lose weight.
So, back to your other question about how to identify if you might have a problem. So, if you’re exceeding moderate drinking levels — which is one drink a day for women — you should probably discuss this issue with your doctor. And they would be able to recommend next steps for addressing concerns. More importantly, if the effects of alcohol are causing problems for you and others, then you might have an alcohol problem. The risk of developing alcohol problems is actually greater for people who have a family history of alcoholism, so something to keep in mind. And there are several warning signs of alcohol problems, such as missing work or school because of drinking, driving while impaired after having alcohol, having a strong urge to drink, needing more alcohol than you previously needed before to get that pleasurable response, finding that people who care about you are concerned about your drinking, and then also having more than seven drinks per week.
So, if you think that you have an alcohol problem, there are ways to get help and there are resources, such as Alcohol Anonymous. Or you can talk to your doctor if you’re concerned that you might have an alcohol problem.
Jamie DePolo: Okay. Dr. Connor, thank you so much. This has been really helpful and insightful. And I think the topic is probably still going to be controversial. But you have shared so much good information with us, I know people are going to be better informed. So, thank you so much.
Dr. Avonne Connor: Thank you for having me today.