Breast cancer is the number one occurring cancer among American women, so when the latest review of research on reducing risk identifies choices that could prevent an estimated 1 in 3 cases, that’s an empowering message for women.
Even better, what if women could implement choices that work double-duty to lower breast cancer risk?
Let’s look at the latest report, and how its findings fit in the picture of overall healthy eating.
The latest report, published by the American Institute for Cancer Research (AICR) and the World Cancer Research Fund (WCRF) from their Continuous Update Project, found strongest evidence for reducing risk of breast cancer by being more active, limiting alcohol, and reaching and maintaining a healthy weight. The first two steps involve specific behaviors. But avoiding weight gain is not a behavior itself – it’s the result of multiple behavior choices playing out in the context of someone’s inherited traits, health and more.
Since there are lots of ways to lose weight – in the short-term – let’s consider how to choose weight management strategies that also show potential to reduce breast cancer risk more directly, outside of effects on body fat.
What’s Weight Got to Do with Breast Cancer?
Whether it’s measured as BMI (body mass index, which looks at weight in relation to height), waist size or the ratio of waist to hip size, high levels of body fat increase risk of postmenopausal breast cancer. Each approximately 10-pound weight gain during adulthood adds more risk.
After menopause, body fat is the body’s main source of estrogen production. More body fat tends to mean higher levels of estrogen available to promote development of estrogen-sensitive cancers. What’s more, an unhealthy excess of body fat can promote development of chronic, low-grade inflammation and insulin resistance (with elevated levels of insulin circulating), and both seem to promote development of breast and other cancers.
Elevated levels of the common measures of a healthy weight are not associated with greater risk of pre-menopausal breast cancer. That likely, at least in part, reflects the already higher levels of estrogen produced in ovaries before menopause, with body fat having less influence. However, since by far the majority of U.S. breast cancer is postmenopausal, and excess weight once gained can be hard to lose, it makes sense to avoid excess weight gain throughout adult life.
With all the headlines about which diet is “best” and celebrities’ extreme weight control practices, it’s easy to forget that several basic steps can go a long way to avoid consuming more calories than your body can use. Focus on making these lifestyle habits – not using them as a short-lived quick-fix.
- Change drink choices to make sugary soft drinks and sugar-laden coffee or chai tea beverages an occasional treat only
- Decrease portion sizes. Or perhaps even better, swap portion sizes to make filling, lower-calorie foods the largest part of your plate
- Find new ways to respond to snack urges that stem from boredom or stress, rather than hunger
Moving More: Protective Even Without Weight Loss
Get physically active in some way on a regular basis, and you lower risk of both pre- and post-menopausal breast cancer. Since even a week of getting out for a walk is unlikely to show up in any change in your weight without a dietary change, it’s all too easy to conclude “It’s not working”. But nothing could be further from the truth!
Making time for at least 150 minutes of brisk walking a week can reduce insulin resistance and the levels of insulin that pose risk, lower estrogen levels, and boost the immune system’s ability to watch for and clear cancer cells.
For people with unhealthy high body fat that reflects a tendency to eat when stressed, getting some form of physical activity every day often helps reduce stress and negative emotions that can trigger overeating. To make it a stress-reducer, choose activity that you enjoy, and keep your thoughts positive…don’t go down that road where exercise is a punishment for overeating or not being “good enough”. Move because you are worth taking care of.
- There’s no need to get all your physical activity at once. For example, you might break it up in to 10-15 minute blocks to start your day, midday and before or after dinner.
- Stopping for that muffin or calorie-laden coffee after exercise usually adds more calories than your body used in activity. Don’t fall in the rut of “rewarding” yourself with high-calorie treats.
- Choose activity that’s likely to be a good match for the extra benefits that are a plus for you: Something social in a group class or with friends, or giving you quiet time you crave? Something with music, or a chance to listen to podcasts and audio-recorded books?
Alcohol: The Overlooked Breast Cancer Risk
Surveys show that many people are unaware that alcohol in excess poses cancer risk. How much is too much? Cancer risk is greatest as alcohol consumption increases. However, even amounts that fit the definition of moderation – no more than one standard alcoholic drink per day for women – pose some increase in risk of breast cancer. And that’s for both pre- and post-menopausal cancers.
The risk doesn’t come from the type of alcohol you choose; it’s from alcohol itself. Alcohol has been identified as a carcinogen, and is metabolized to another compound (acetaldehyde) that is also a carcinogen, with capacity to create DNA damage that leads to cancer. Moreover, alcohol tends to raise body levels of estrogen and androgen hormones that pose breast cancer risk. Especially at high levels, alcohol can also disrupt metabolism of folate, a B vitamin that is needed to maintain healthy DNA.
Alcohol is also a concentrated source of calories, so cutting down can help with weight control. Moreover, some people find by limiting alcohol, they avoid loosened inhibitions that lead to overeating or less-healthy choices.
Whether you choose to avoid alcohol completely or simply limit how much you drink, make sure that your choices also support the goal of reaching and maintaining a healthy weight.
- If you don’t want to avoid alcohol completely, choose at least a few alcohol-free days each week, and stick to the moderation limit on other days.
- Some wine-lovers may prefer to enjoy one glass of a favorite wine, and then switch to non-alcoholic options. Others may prefer to get the same limited alcohol by choosing a wine spritzer, with half wine and half club soda or sparkling water.
- Find non-alcoholic drinks you enjoy that are low-calorie or calorie-free. Swapping alcohol for sugar-laden sodas or “mocktails” loaded with sugar and juices does not help limit calories. Try fruit-infused waters or other low-sugar drink options, or keep a pitcher handy of fridge-brewed ice tea made with interesting flavored teas or cold-brewed coffee (decaf if preferred).
- If alcohol is your way to reduce stress, explore how yoga, meditation or exercise might be even more effective. If alcohol is your way to socialize, switch some social opportunities to doing a physical activity together, whether hiking, going for a walk, or cycling.
Plant Foods’ Potential
To reduce overall cancer risk, an eating pattern that focuses around plant foods is the recommended choice. The new AICR/WCRF CUP report, summarizing all available high-quality evidence, concluded that research on these foods was too limited to be specifically recommended to reduce breast cancer risk.
However, the CUP Expert Panel identified evidence as “Limited Suggestive” that non-starchy vegetables and foods high in carotenoids may play a role in reducing breast cancer risk. Analysis did not link non-starchy vegetables (which includes veggies other than potatoes, corn and legumes) with overall breast cancer risk, but to ER-negative/PR-negative cancer specifically. Natural plant compounds (phytochemicals) in vegetables may reduce levels of a certain growth factor (EGF) that otherwise can promote growth, spread and survival of breast cancer cells. Researchers suggest that this protective effect may simply be easier to detect in breast cancers that are not already strongly driven by estrogen sensitivity.
Carotenoid-rich foods include a wide range of vegetables and fruits, since these compounds include beta- and alpha-carotene, lycopene, lutein and more. Circulating levels of several are tentatively linked with lower risk of breast cancer. Carotenoids could act through several pathways to reduce breast cancer development, though higher carotenoids can also be a marker of higher vegetable and fruit consumption, providing a wide array of cancer-protective compounds.
Research analysis on which the CUP report was based links higher intake of dietary fiber, especially soluble fiber, with lower breast cancer risk, although the report’s expert panel rated these links as too limited to support any conclusions. Still, it’s possible that dietary fiber could play a role in reducing breast cancer risk by binding estrogen secreted into the gut and thus leading to lower circulating estrogen. Also, soluble fiber is often the viscous type that can be fermented by gut microbes, leading to anti-inflammatory effects.
Since by far the stronger link to reducing breast cancer involves keeping a healthy level of body fat, use consumption of plenty of vegetables and fruits to support that larger goal.
- Make portions of higher-calorie foods smaller, filling up on vegetables and fruit instead.
- Watch out for health halos on vegetables. Check restaurant menus thoughtfully to select those that are not smothered in calorie-laden toppings and sauces.
- Try fruit for a snack instead of reaching for chips, candy or bakery.
Almost all diets can lead to weight loss, at least for a few months. Instead of something that would be difficult or unhealthy to continue, make small swaps and changes one step at a time to establish habits that help you lose an unhealthy excess body fat or stop weight gain while doing double-duty to reduce risk of breast cancer through other means, too.
How much alcohol is in that drink? Increased portion sizes and the popularity of higher-alcohol wines and craft beers can mean that what you think is one drink counts as one-and-a-half or two! This appendix to the Dietary Guidelines for Americans can clarify what’s in your choices.
Looking for alternative beverages that can still keep calories low when you want something more than cool, refreshing unaltered water? The Food Network offers inspiration for fruit-infused water, and several choices in AICR’s special summer drinks fit the bill, too.
Cold-brewed ice tea is easy to make and can feature blends or additions that make it a drink to savor without the risks of alcohol or a big calorie load. Even Bon Appétit raves about it. And if you’re new to making cold-brewed coffee, Bon Appétit offers tips on that, too. Remember, if you’re looking for a swap for evening alcohol, you can make this with decaf.
How to enjoy giving vegetables a larger role in your eating habits? AICR’s New American Plate does that while addressing the goal of reaching and maintaining a healthy weight. Oldways is one of my favorite go-to sources online when I’m looking for a fun way to add delicious pizazz to vegetables.
World Cancer Research Fund International/American Institute for Cancer Research. Continuous Update Project Report: Diet, Nutrition, Physical Activity and Breast Cancer. 2017. Available at: http://www.aicr.org/continuous-update-project/breast-cancer.html
Alcohol and Cancer fact sheet. National Cancer Institute, National Institutes of Health. (Reviewed June 24, 2013)
Scoccianti C et al. European Code against Cancer 4th Edition: Alcohol drinking and cancer. Cancer Epidemiology. 2016; 45:181–188.
Testino G et al. Alcohol Consumption and Cancer: A Literature Search and a Proposal. Ann Public Health Res. 2016; 3(1): 1036-1043.