A Breast Cancer Research journal article discusses two studies: one from Sweden and one from Germany.
The Swedish study compared the health histories, including coffee drinking, of 2,818 women diagnosed with breast cancer after menopause to the health histories of 3,111 similar postmenopausal women not diagnosed with breast cancer.
The German study compared the health histories, including coffee drinking, of 3,464 women diagnosed with breast cancer after menopause to the health histories of 6,657 similar postmenopausal women not diagnosed with breast cancer.
Both studies confirmed well-recognized links to higher breast cancer risk, including:
- family history
- being overweight or obese
- drinking alcohol
The researchers adjusted for differences in health factors linked to breast cancer risk between the diagnosed and undiagnosed women. After the adjustments, the researchers found that drinking more than five cups of coffee per day was linked to a much lower risk of hormone-receptor-negative breast cancer in postmenopausal women:
- Women who drank at least five cups of coffee per day were 57% less likely to be diagnosed with hormone-receptor-negative breast cancer after menopause in the Swedish study.
- Women who drank at least five cups of coffee per day were 33% less likely to be diagnosed with hormone-receptor-negative breast cancer after menopause in the German study.
Hormone-receptor-negative breast cancers are cancers that do not have receptors for the hormones estrogen or progesterone. Hormone-receptor-negative breast cancers are less common than hormone-receptor-positive breast cancers and tend to be more aggressive.
Drinking a lot of coffee also was linked to a lower risk of postmenopausal hormone-receptor-positive breast cancer in these studies. Still, the link to a lower risk of postmenopausal hormone-receptor-negative breast cancer was stronger.
The best news from the results is that no link between coffee and higher breast cancer risk was found. This is reassuring to all of us who drink quite a bit of coffee. Still, drinking a lot of coffee can disrupt your sleep and cause other undesirable health effects. As with most diet and lifestyle matters, moderation is a good approach.
In the updated and expanded Breastcancer.org Lower Your Risk section you can learn much more about diet and lifestyle choices you can make to help keep your risk of breast cancer as low as it can be.