We all know that smart lifestyle choices directly translate to a healthy mind and body, but did you know that certain lifestyle choices can decrease your risk of breast cancer? A recent review[1] confirmed that lifestyle choices that have been earmarked since 2016 as being of benefit to reducing breast cancer risk, are still valid. These include minimizing your alcohol intake, not smoking, maintaining a healthy weight, and ascertaining risk when taking hormone therapy.
Lifestyle Habits and Breast Cancer
Alcohol
All levels of alcohol consumption – even light drinking – are associated with a higher risk of breast cancer. The fact that breast cancer risk is directly proportional to alcohol consumption has been known for a long time, but the relationship between alcohol intake and breast cancer is a complex one.
There are different types of alcohol as well as different ingredients in various alcoholic beverages. Alcohol metabolism is also genetically determined and highly individual. The risk of breast cancer linked to alcohol consumption is therefore not only dependent on the type of alcohol consumed but also the quantity, whether it is consumed with food and how it is individually metabolized.
Additionally, almost all cancer therapies have some harmful effects on cardiovascular health. The well-documented cardioprotective effects of light alcohol consumption also seem to hold for therapy-induced cardiovascular toxicity. In a large Californian study[2], cancer recurrence rates were lower in teetotalers, but cardiovascular incidents were more common, so in the end both groups had the same survival.
So your best bet is to stick to the safest path of moderation of a maximum of one glass of wine a day. It may increase your breast cancer risk, but it will also have health benefits and less toxic repercussions than some other lifestyle vices that we all have.
Smoking
Aside from the fact that smoking causes several other health problems, it is also directly related to a higher risk of breast cancer.
Research[3] has shown that both active and passive smoking can increase breast cancer risk. According to The Institute of Cancer Research[4], ‘Those who began smoking before the age of 17 were found to be at around a 24% increased risk of developing the disease, while those who started smoking between the ages of 17 and 19 had an increased risk by about 15%.’
They also found that ‘smoking for more than ten years had a relative risk increase of around 21%, while those who smoked for more than 30 years had an increased risk of breast cancer of around 22%, compared with women who had never smoked.’
The recommendation from this and similar studies is to avoid starting to smoke in the first place. If you’re already a smoker now is the time to quit.
Exercise and body weight
According to the MD Anderson Cancer Centre[5], being overweight does affect your breast cancer risk. However, the effect is different before and after menopause.
Pre-menopause, there is no additional risk of breast cancer if you are overweight, but the negative repercussions of obesity or too high a Body Mass Index (BMI) far outweigh any breast cancer risk concerns. Post-menopause, it’s a different story. After menopause, your breast cancer risk increases by about 12% for every five-point increase on the BMI scale.
The American Cancer Society recommends 2.5-5 hours of moderate physical activity a week or at least 1-2 hours of vigorous activity per week to decrease your risk of cancer overall. This activity can be split over days, it doesn’t all have to occur at one time.
Birth control & hormone therapy
The risk of developing breast cancer should be weighed against the important benefits of hormonal contraceptives, such as good contraceptive efficacy and reduced risks of ovarian, endometrial, and perhaps colorectal cancer (at least for combined oral contraceptives that were commonly used in the 1970s and 1980s)[6].
It is wise to discuss the risks with your gynecologist. There are, however, numerous lifestyle changes you can make to decrease the risk of developing breast cancer without changing birth control.
Breast cancer risk appears to be higher with daily progesterone (continuous combination Hormone Replacement Therapy) than with less frequent progesterone (sequential or cyclical combination Hormone Replacement Therapy)[7]. The very popular progestogen-releasing intrauterine contraceptive devices also have this effect[8].
The American Cancer Society says estrogen-only HRT is not linked to a higher risk of breast cancer. Since many women do benefit from hormone therapy, it’s advised that you consult with your health practitioner on alternate options if possible or try the lowest dose possible.
References
- Mertens, E., Barrenechea-Pulache, A., Sagastume, D. et al. Understanding the contribution of lifestyle in breast cancer risk prediction: a systematic review of models applicable to Europe. BMC Cancer 23, 687 (2023). https://doi.org/10.1186/s12885-023-11174-w
- Kwan ML et al, JCO 2010 Oct 10; 28(29): 4410-4416
- https://bmccancer.biomedcentral.com/articles/10.1186/s12885-023-11174-w
- https://www.icr.ac.uk/news-archive/smoking-particularly-if-started-during-adolescence-is-associated-with-an-increased-risk-of-breast-cancer-major-new-study-finds
- https://www.mdanderson.org/publications/focused-on-health/breast-cancer-and-weight-whatsthelink.h191592991.html#:~:text=After%20menopause%2C%20your%20breast%20cancer,can%20influence%20breast%20cancer%20risk.
- https://www.un.org/en/development/desa/population/publications/pdf/family/trendsContraceptiveUse2015Report.pdf
- Breastcancer.org
- Acta Oncol 2016;55(2):188-92. doi: 10.3109/0284186X.2015.1062538. Epub 2015 Aug 4
