This post was originally published in June 2015, and has been updated.
Considering your breasts change over your lifetime — and to a lesser degree over the course of a month — it’s important to understand the connection between them and your hormones.
Here are five ways to better understand your breasts, their connection to your health and how you can use this knowledge to reduce your risk of breast cancer.
1. Breast tenderness says a lot about your hormones
You might experience severe breast swelling and discomfort some months, while others reveal less distinct warning signs that your menstrual cycle is right around the corner. But know that if, when, and where you have soreness says a lot about your hormones.
According to Jerilynn Prior, a researcher and professor of endocrinology at the University of British Columbia, premenstrual breast tenderness at the sides of the breast under the armpits may suggest that ovulation has occurred during that cycle. If the breasts are sore up front and over the nipples, Prior says this may suggest increased levels of estrogen before a period.
Bottom line: One study suggests that breast pain may be caused by a decreased ratio of progesterone to estrogen in the second half of the menstrual cycle. For an accurate picture, you can take a blood test to measure estrogen hormones.
2. Breast pain? Check your bra
A 2013 survey reported that one third of female marathon runners experience breast pain during an event.
While half blamed breast pain on their menstrual cycle, almost 30 percent said that it was only sometimes the cause. Another 12 percent said that hormonal factors worsened their breast pain, and one in seven said that exercise made their symptoms worse.
Bottom line: I recommend every woman get properly fitted for a bra (watch the video below) and sports bra. Also, chuck your bra at the door when you get home to relieve discomfort. If pain persists, talk to your physician.
3. Shrinking breasts can indicate changing hormones
Your breasts are essentially masses made up of glandular tissue, supportive tissue and fat cells. As a result, they are very sensitive to any changes in your hormone levels, particularly estrogen and progesterone. This is why your breasts will swell when pregnant, on the birth control pill and/or before your period.
As estrogen levels fall, with impending menopause, you may find the opposite happens. Another reason for a reduction in breast size is simply weight loss, since after all, fat cells don’t always shrink in the areas we want them to.
Bottom line: Menopause and weight loss are generally the culprits for shrinking breasts, but if not, you may want to talk to your doctor.
4. Covet your sleep to preserve the health of your breasts
Low levels of melatonin, released only while we sleep in darkness, may be associated with higher risk of breast cancer. A 2013 study found that working long-term night shifts (30 years or more) may double your risk factor.
Another study, published in the International Journal of Cancer, also found the risk of developing breast cancer was higher in women who worked nights compared to women didn’t.
Bottom line: While you can’t always change your job, there is a solution. Studies suggest that melatonin supplements can help those with disrupted circadian rhythms (like night-shift workers and frequent travellers) to sleep better.
5. (Don’t) drink to breast health
More than four servings of alcohol per week increases your breast cancer risk and the recurrence of breast cancer. The risk is especially high when several drinks are consumed at one time.
Bottom line: Stick to two drinks (or fewer) a week to decrease the harmful effects on your breast tissues.
Of course, you can always switch beverages. One study found that opting for two cups of coffee a day may reduce early breast cancer growth recurring in patients taking Tamoxifen (which is used to treat breast cancer). I recommend you stick with fewer than three cups per day however.
Another key for prevention? Up your veggie intake — it’s associated with a lower risk of estrogen receptor-negative (ER-) breast cancer, according to research published in the Journal of the National Cancer Institute.
Natasha Turner, N.D. is a naturopathic doctor and founder of the Toronto-based Clear Medicine Wellness Boutique. For more wellness advice from Natasha Turner, click here.