Study: Caffeine Does Not Increase Your Risk for Breast Cancer

A recent study from the University of Buffalo concluded that postmenopausal women who drink caffeinated drinks such as coffee and tea do not have a higher risk of developing breast cancer because of their caffeine consumption.

In a press release, Kexin Zhu, an epidemiology PhD student in the University at Buffalo’s School of Public Health and Health Professions and an author of the study said that “the overlap of age at diagnosis of breast cancer and age with high consumption of caffeine, and the inconsistent findings from previous studies” motivated the researchers “to study whether this lifestyle factor could affect breast cancer risk in postmenopausal women.”

For the new study, which was published in the International Journal of Cancer, the researchers evaluated data on almost 80,000 women who are part of the Women’s Health Initiative Observational Study, an ongoing nationwide study that surveyed 161,000 women between 1992 and 2005. The University at Buffalo is one of 40 study sites involved in the research.

The participants completed yearly health questionnaires that asked them about their health habits. Their answers are helping researchers learn more about the link between lifestyle patterns and disease.

When they looked at the results, the researchers initially found a 12% higher risk of invasive breast cancer in women who reported drinking two to three cups of caffeinated coffee per day. However, after adjusting for family history, physical activity, reproductive history, alcohol consumption, and tobacco use, that finding was not considered to be statistically significant.

“I think it’s important for people to know they can feel safe drinking coffee every day,” Lina Mu, PhD, MD, associate professor of epidemiology and environmental health at the University at Buffalo and the study’s senior author, tells Verywell. “This data is powerful and provides strong evidence to show there is no association between caffeine consumption and breast cancer.”

Caffeine and Fibrocystic Breasts

Jane Emilie Mendez, MD, chief of breast surgery at the Miami Cancer Institute, Baptist Health South Florida, tells Verywell that caffeine can be problematic in some cases. For example, even the small amount of caffeine that is found in chocolate may increase breast pain in premenopausal women who have fibrocystic breasts.

Fibrocystic breasts are a benign condition in which the breast tissue is dense and lumpy. In people with the condition who have yet to go through menopause, fibrocystic breasts can cause pain that may or may not be associated with their menstrual cycle. As they age, the denser breast tissue turns into softer fatty tissue, and the breast pain decreases.

Get Your Routine Screenings

Mendez emphasizes that 85% of breast cancers occur sporadically with no familial or genetic link. People should not think that routine screenings are less critical just because they do not have a family history of breast cancer.

“One of the myths [surrounding breast cancer] is ‘I don’t have breast cancer in my family, how come I got it?’” says Mendez. “But the two greatest risk factors are being a woman and getting older. The likelihood increases with age.”

Whether or not you have risk factors, performing monthly self-breast exams is an important preventive step. “It’s important for women to know what’s normal for them so if they notice anything different, they can seek care,” says Mendez.

According to Mendez, premenopausal people should perform self-breast exams the week after their menstrual periods because this is when their breast tissue returns to baseline after going through the hormonal changes of their cycle. Postmenopausal people should perform breast self-exams on the same day each month.

People who are at average risk for developing breast cancer should also have a mammogram once yearly, starting between the ages of 45 and 50. People with a family history of breast cancer or other risk factors should be screened earlier. Talk to your primary care provider about when to start having mammograms.

Mendez says that she’s been seeing patients, most in their 40s and 50s, with more advanced breast cancer, as many people have put off mammograms during the COVID-19 pandemic.

“I think it’s important to emphasize that breast cancer does not discriminate,” says Mendez, adding that women should know their bodies and family histories, and follow the breast cancer screening guidelines.