6 little-known habits that can increase cancer risk for women

It is well-known your genes, hormones, and lifestyle behaviors affect your chances of getting breast cancer. Eating healthy and exercising prevents weight gain, and thus, offsets your disease risk. However, there are simple habits, from drinking alcohol to working late nights, that can actually lead to a breast cancer positive mammogram.

In the spirit of Breast Cancer Awareness Month, avoid these six surprising habits that may be harming your breast health. 

1. Birth Control Pills

Estrogen in birth control pills is effective in stopping unwanted pregnancies, but it can become a cause for concern when it comes to breast cells. High doses of the hormone in the blood can increase a woman’s breast cancer risk by overstimulating breast cells. A 2014 study published in the journal Cancer Research found recent use of oral contraceptives among women ages 20 to 49 was associated with an increased breast cancer risk, depending on the formulation. High-dose estrogen (50 micrograms or more) birth control pills was linked to a higher risk of breast cancer in younger women, but using these pills with a low dose of estrogen (20 micrograms) was not. 

2. Not Breastfeeding

The choice of whether or not to breastfeed is a personal one, but women who decide not to breastfeed may face a higher risk of breast cancer. In a 2002 study published in the journal Lancet, researchers analyzed data from 47 previous studies, to show breastfeeding slightly lowers a woman’s risk of breast cancer. The longer a woman breastfed (every 12 months), the lower her risk was compared to those who never or briefly breastfed (10 months) their children.

A more recent study published in the Journal of the National Cancer Institute provides further evidence breastfeeding can lower breast cancer risk as well as a woman's prognosis if she’s diagnosed. Breastfeeding women had a 30 percent lower risk of recurring breast cancer and a 28 percent reduced risk of dying from their breast cancer. The researchers still have yet to investigate further the exact cause and effect between breastfeeding and breast cancer. 

3. Extra Pounds

The higher your skirt size gets over the years, the higher your risk for postmenopausal breast cancer. A study published in the journal BMJ Open found women who went up a skirt size every decade between their 20s and 60s, increased their risk by 33 percent compared to the 77 percent risk for those who increased two sizes per decade. Skirt size provides a window of the wearer’s abdominal fat, suggesting a link between weight gain and breast cancer risk. Although no one knows how fat contributes to this correlation, researchers believe it’s because body fat around the waist is metabolically more active than other fat tissue in the body. 

4. Alcohol

You can blame it all on the alcohol when it comes to your breast cancer risk. The amount of alcohol consumed increases the risk of developing breast cancer, especially those who have two to five drinks daily, according to the American Cancer Society. A 2011 study published in The Journal of the American Medical Association examined the quantity, frequency, and age at which women consumed alcohol from 1980 to 2008. The findings revealed having 5 to 10 grams of alcohol a day, or 3 to 6 glasses of wine a week, raised the risk of breast cancer by 15 percent. With each 10-gram increase in alcohol use per day, the risk climbed 10 percent. 

5. Eating Too Late

A late night snack can satisfy your cravings but become detrimental to your breast health. A recent study published in the journal Cancer Epidemiology, Biomarkers & Prevention found eating meals at set times and dining early in the evening can reduce a woman’s risk of developing breast cancer due to glucose. When you eat, the body breaks down the sugars and starches into glucose, entering the bloodstream. The glucose is then directed by insulin to your cells, so it can be used for energy. A lack of insulin can cause blood sugar levels to rise and stay high, which is linked to an increased risk of breast cancer. 

6. Working Too Late

Shift work may be unavoidable for you, but it could wreak havoc on your health. Working the night shift is known to disrupt the body’s circadian clock, leaving you physically exhausted and sleep-deprived, and it can also raise your risk of breast cancer. A 2012 study published in the journalOccupational and Environmental Medicine found women who worked night shifts were up to four times more likely to develop breast cancer than those who didn’t work nights. The effect was cumulative as women who worked at least three night shifts a week for six years had twice the risk as those who worked one to two night shifts per week.

The researchers speculated the disruptions to the body’s internal block led to changes in hormone levels. Since these employees work at night and sleep during the day, this alters the circadian rhythm and the levels of melatonin — a hormone responsible for regulating sleep and wake cycles. Lower levels of melatonin are more seen in breast cancer patients than women without the disease. 

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