Understanding the Connection Between Caffeine and Breast Cancer

Role of Caffeine in a Woman's Health

Woman holding coffee cup

What is Caffeine?

Caffeine is a natural plant chemical that acts as a stimulant. It's the most commonly used drug in the world and is found in a number of products like:

  • coffee
  • tea
  • soft drinks
  • cocoa or chocolate food products
  • certain medications (i.e. Excedrin)

What is the Link Between Caffeine and Breast Cancer?

Caffeinated drinks do not raise a person's risk for breast cancer. In fact, they may slightly decrease the risk of developing breast cancer in postmenopausal women, according to a 2013 large meta-analysis study in Gynecologic Oncologic.

The "why" behind this link is still unclear. One reason could be that caffeine contains chemicals called polyphenols that have been found to interfere with the start and progression of cancer growth.

Caffeine may affect other aspects of breast health. For instance, some women with fibrocystic breast tissue notice that when they avoid caffeinated products like coffee, tea, chocolate, and soft drinks, their breast symptoms improve. While the scientific data to support this is not quite there, it's probably worth the effort if a woman is experiencing discomfort. 

In addition, there is debate over whether caffeine may increase the risk of developing breast cancer in women with benign breast disease — or non-cancerous breast conditions. This was found to be true in one 2008 study in Archives of Internal Medicine, but only with very high consumption of coffee, at 4 or more cups per day. This is still controversial though, and not supported by other studies.

Is There a Link Between Caffeine and Other Women's Health Issues?

Caffeine also affects bone health, likely by decreasing calcium absorption in the body. In addition, women may choose to drink caffeinated beverages, over milk or other calcium-rich drinks — which further contributes to bone loss.

According to the National Osteoporosis Foundation, drinking more than 3 cups of coffee each day may cause bone loss — so sticking to 3 or fewer cups of coffee is probably ideal for your bone health.

What Should I Do?

While caffeine does not appear to play much of a role in your breast health, moderation is probably your best bet. To reduce your risk of breast cancer, focus on these nutritious and lifestyle habits like:

  • eating a diet rich in fruit and vegetables
  • getting regular physical exercise
  • avoiding or limiting your alcohol consumption
  • maintaining a normal body mass index 


American Cancer Society. Diet and Activity Factors That Affect Risks. Revised: 03/19/2008.

Archives of Internal Medicine, 2008;168(18):2022-2031. Caffeine Consumption and the Risk of Breast Cancer in a Large Prospective Cohort of Women. Ken Ishitani, MD, PhD; Jennifer Lin, PhD; JoAnn E. Manson, MD, DrPH; Julie E. Buring, ScD; Shumin M. Zhang, MD, ScD.

American Cancer Society. (2015). Non-Cancerous Breast Conditions:Fibrosis and simple cysts. 

Jiang W, Wu Y, & Jiang X. Coffee and caffeine intake and breast cancer risk: an updated dose-response meta-analysis of 37 published studies. Gynecol Oncol. 2013 Jun;129(3):620-9.

National Osteoporosis Foundation. Food and Your Bones. Retrieved October 15th 2015. 

Ramos S.: Cancer chemoprevention and chemotherapy: dietary polyphenols and signalling pathways. Mol Nutr Food Res 2008; 52: pp. 507-526