In the past, caffeine has been somewhat of a complex or even controversial topic. While some research shares that it is bad for health, others laud caffeine’s ability to enhance alertness, improve mood, and even boost metabolism. According to Medical XPress, a research team from the University of Buffalo recently sought to understand the association between caffeine and invasive breast cancer. Could drinking coffee or tea raise the risk of developing invasive breast cancer? Well, researchers ultimately determined that there was no strong association between the two. 

Interested in learning more? Take a look at the study findings published in the International Journal of Cancer. 

Caffeine

To begin, it’s first important to have at least a baseline understanding of what caffeine is. According to Healthline, caffeine is: 

A natural stimulant most commonly found in tea, coffee, and cacao plants. It works by stimulating the brain and central nervous system, helping you stay alert and prevent the onset of tiredness.

Historically, researchers have identified caffeine consumption as far back as 2737 BC. Now, this stimulant is widely used daily – with up to 90% of Americans consuming some caffeinated product daily. 

The Research

Within this study, researchers wanted to learn whether caffeine consumption was associated with an increased risk of invasive breast cancer. In the past, some studies have argued that there was a negative association; others, a positive. Regardless, it is clear that menopause, caffeine consumption, and breast cancer diagnoses often occur around similar ages. For many females, menopause occurs in their 50s; the highest consumers of caffeine are in groups aged 50-64. Finally, the average breast cancer diagnosis usually occurs around age 62. Thus, researchers believed that this study could clarify whether any association existed.

Altogether, researchers sourced data from 79,871 postmenopausal American women. Most of the data were sourced from the Women’s Health Initiative Observational Study. Over the last ten years, women within the study filled out health questionnaires regarding their overall health, their diets, exercise patterns, and other health-related information. Findings include:

• Out of the 79,871 women, only 4,719 women (5.9%) had invasive breast cancer after a median 16-year follow-up period.
• Initially, women who drank 2-3 cups of caffeinated coffee daily saw a 12% increased risk of invasive breast cancer, with those drinking decaf at 22%. However, when including other lifestyle elements, such as how much alcohol someone drank or whether they smoked cigarettes, there was no actual significant risk increase. 
• Unfortunately, the research as to why decaf consumption had a higher risk than caffeine consumption – at least at first – was unclear. 
• Similarly to coffee, those who drank tea did not have a higher risk of developing invasive breast cancer.
• Ultimately, researchers determined that there is no strong association between caffeine intake and breast cancer risk while accounting for other environmental and lifestyle factors.

Breast Cancer 

As the name suggests, breast cancer forms in breast tissue. While it can affect both males and females, breast cancer is the 2nd most common cancer found in females. In general, doctors do not know the cause of breast cancer. However, in an estimated 10-15% of cases, BRCA gene mutations cause breast cancer. Patients with these mutations are also at an increased risk of ovarian cancer. Additional risk factors for developing this cancer include early menstruation or late menopause, obesity, and never having been pregnant.

As you saw above, researchers wanted to explore the link between invasive breast cancer and caffeine consumption. Invasive breast cancers are those which spread into surrounding tissue, such as triple-negative breast cancer. A large number of breast cancers are considered invasive. However, some may not spread; these are called non-invasive breast cancers.

Symptoms of breast cancer include:

• Lump in the breast tissue 
• Breast redness or tenderness
• Inverted nipples
• Abnormal nipple discharge
• Breast size, shape, or appearance changes
• Peeling, scaled, flaking, or crusting breast skin