Triple Negative Breast Cancer and Coffee: Is There a Connection?

The link between coffee and triple-negative breast cancer is unclear. Some lifestyle habits may help reduce cancer risk, but they can’t prevent or cure it.

A triple-negative breast cancer (TNBC) diagnosis can bring up so many questions, including what to eat and drink.

Your morning cup of coffee, for instance: Is it still a healthy choice?

Here’s what the cancer research tells us (and doesn’t) about the association between triple-negative breast cancer and caffeine, other foods, and lifestyle choices.

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What’s the link between coffee and triple-negative breast cancer?

Scientists are still trying to answer questions on the link between foods and drinks, including coffee consumption, and TNBC.

TNBC is an aggressive form of breast cancer that lacks the three most common hormonal receptors targeted by traditional therapies. Doctors diagnose TNBC via a mammogram, ultrasound, or magnetic resonance imaging (MRI) depending on the size of the tumor.

“Many individuals recently diagnosed with triple-negative breast cancer are looking for answers and are wary of accidentally exposing themselves to items that could worsen their condition,” says oncology nutritionist Sarah Herrington, MS.

However, caffeine’s role in breast cancer is unclear.

For instance, one 2020 study assessed the potential effects of combining caffeine with cisplatin, a chemotherapy drug, in a laboratory setting. The data suggested that caffeine could strengthen cisplatin’s effectiveness.

A 2021 study of nearly 80,000 postmenopausal people indicated there was not a significant association between the number of cups of coffee or tea a person had per day and invasive breast cancers.

Another 2021 study of 8,900 people indicated that higher coffee intake after a diagnosis was linked with higher breast cancer and overall survival odds. It also suggested that more tea consumption might improve chances.

A large but older study of more than 42,000 women indicated that coffee drinkers had lower risks of developing all breast cancer types.

However, these studies aren’t specific to TNBC.

The current takeaway? As frustrating as it might be, the evidence is not conclusive.

Does coffee help prevent breast cancer?

The research on the link between breast cancer prevention and coffee consumption is still unclear. Breast surgical oncologist Christopher M. McGreevy, MD notes that some studies indicate that coffee consumption might be protective, but the keyword is “might.”

“Others have found no association or even a slight increase in risk,” McGreevy says. “More research is needed to definitively determine the relationship between coffee consumption and breast cancer.”

Based on what we can glean from the current research, moderate coffee consumption of 3 to 5 cups daily likely doesn’t increase breast cancer risk for most people.

However, other risk factors influence breast cancer risk, such as:

• lifestyle
• genetics
• family history
• stress

What’s the link between breast cancer and caffeine in general?

As above, the research isn’t definitive.

The 2021 study mentioned above indicated that tea consumption after a breast cancer diagnosis might improve survival odds, and the one from 2015 suggested tea and caffeine might reduce breast cancer risk.

However, more research is needed to determine whether these trends would remain consistent in different study settings.

“Additionally, the caffeine content in these beverages can vary significantly, making it difficult to assess their potential impact on TNBC outcomes,” McGreevy says.

Importantly, healthcare professionals generally recommend limiting caffeine intake through high sugar drinks or energy drinks because these can negatively affect overall health.

What’s the link between food and triple-negative breast cancer?

Are other foods linked to triple-negative breast cancer? Once again, the data is inconclusive.

Eggs

Eggs are a good source of protein and choline, a nutrient that can aid brain health.

However, an older 2016 study suggested that eggs are associated with higher TNBC risk. Still, experts say the research remains limited and don’t recommend removing moderate egg consumption from your diet if it’s a food you enjoy.

“There is no conclusive evidence linking egg consumption to an increased risk of TNBC,” says comprehensive breast surgeon Karishma Kollipara, DO. “Moderate consumption is generally considered part of a healthy diet.”

Intermittent fasting and fasting-mimicking diets

Intermittent fasting involves fasting and eating at regular intervals.

McGreevy explains that intermittent fasting’s potential benefits in lowering the risk of cancer recurrence could be attributed to insulin metabolic health.

However, a 2023 systemic review didn’t find a link between intermittent fasting and a better quality of life or tumor return in people with breast cancer. The study also found limited evidence suggesting that the dietary approach might help with toxicity resulting from chemotherapy treatment.

Research from 2021 indicated that a fasting-mimicking diet involving eating limited amounts during the “fasting” period might have a positive effect.

It may come down to weight loss.

“Weight loss has been shown to improve outcomes, including survival after diagnosis of breast cancer,” says McGreevy. “Intermittent fasting can be a tool that can help promote a healthier body weight.”

Still, more specific research on TNBC and intermittent fasting is needed.

Vitamin B12 and other B vitamins

Research from 2023 did not suggest a link between breast cancer and vitamin B12 found in fish, dairy, and meat. It also indicated that:

• vitamin B1 (thiamine) was linked to increased breast cancer risk.
• vitamin B3 was linked to lower breast cancer risk.
• there was not a significant link between vitamin B5 and breast cancer.

Older research from 2016 suggested the data regarding vitamin B12 and breast cancer risk was inconsistent. However, the authors indicated that the odds for cancer were “somewhat greater” in people with lower folate levels or with higher alcohol intake.

Herrington notes that B12 is essential for combating low hemoglobin levels, a protein in red blood cells.

“As anemia often presents simultaneously with cancer, adequate intake of blood-building nutrients is critical,” Herrington says. “However, there are also certain B vitamins … that may warrant limitation during cancer treatment.”

Exercise and triple-negative breast cancer

Exercise is a first-line recommendation for overall health. What about breast cancer risk?

“Regular physical activity can enhance immune function, reduce inflammation, and improve overall quality of life,” Kollipara says.

One 2020 rodent study on TNBC and physical activity suggested that exercise reduced tumor growth.

A review from 2023 indicated that “energy balance” through diet and exercise changes could help improve chemotherapy response in people with TNBC.

Another 2023 review also pointed to data suggesting the benefits of exercise in people with TNBC.

“Plan for at least 150 minutes of moderate-intensity exercise or 75 minutes of high-intensity exercise per week to improve your outcomes and your overall health,” Kollipara says.

She recommends aerobic exercises, such as:

• walking
• running
• cycling
• hiking
• swimming
• rowing

Kollipara also suggests resistance training.

How to prevent triple-negative breast cancer

There’s no way to prevent triple-negative breast cancer completely, but lifestyle habits may reduce risk.

Examples include:

• maintaining a healthy weight
• limiting alcohol
• reducing or quitting smoking
• regular exercise
• eating nutritious foods
• lactating, if possible/applicable

Additionally, McGreevy suggests considering genetic testing if you have a significant family history of breast cancer and attending regular screening mammograms. TNBC is highly related to genetic variants, so it’s important to get genetic testing if you’re diagnosed.

“Screening mammograms have been shown to significantly improve survival for breast cancer and are extremely important,” McGreevy says, adding that discussing individualized care with your doctor is key.

Takeaway

Researchers are still trying to understand the potential relationship between triple-negative breast cancer and caffeine, a key component in coffee.

Coffee doesn’t appear to increase a person’s risk for TNBC or interfere with treatment, survival, or reoccurrence. Research on other dietary choices like eggs is similarly limited and inconclusive.

Discuss your family history and concerns with a healthcare professional to ensure customized care.