Breast Cancer Myths and Facts, According to a Cancer Expert

October is Breast Cancer Awareness Month, and as someone who works in cancer research, I’ve been proud to see the progress we’ve made improving detection, diagnosis, and treatment of breast cancers. As an immunologist, I aim to understand the factors that contribute to the disease and work in novel treatment development. Outcomes are better than they’ve ever been, and that’s thanks to decades of scientific progress.

While our understanding of breast cancer is improving, there’s still misinformation that circulates and jeopardizes our progress. Cancers are hundreds of incredibly complex and unique diseases; this makes them an easy target for myths and misinformation. Social media accelerates the spread of false claims that create unnecessary fear and health anxiety. And while that may seem fairly innocuous, these falsehoods can impact your ability to make accurate decisions — decisions that could save your life.

Myths about breast cancer lead to the avoidance of foods and products that are perfectly safe, cause refusal of preventive health measures, and lead people to seek incorrect medical advice. It can be difficult to determine what’s accurate and what’s not, but since cancer misinformation can literally cost people their lives, let’s debunk six common breast cancer myths once and for all.

Myth: Aluminum-containing antiperspirants cause breast cancer.

This is arguably one of the most persistent myths out there. It stems from two false beliefs. One, that aluminum salts in antiperspirants “poison our bodies” when they’re absorbed by the skin, and two, that the same process that reduces sweating blocks the removal of toxins. As a result, toxins and harmful substances build up in the lymph nodes and lead to cancer.

Reality: There’s no evidence to support either of these claims.

The amount of aluminum (in the form of salts in antiperspirant) that you might absorb through your skin is miniscule — hundreds of times less than the amount you’re exposed to normally from food and water, per a 2019 study in the journal Skin Pharmacology and Physiology.

There’s also no science to support the notion of “toxins” accumulating in breast tissue. Our liver, kidneys, and lungs do our detoxification—not our sweat glands. Sweating aids in regulating our body temperature, which is why your body is covered with sweat glands.

Decades of data show no link between breast cancer and aluminum exposure from both antiperspirants, nor from other sources like food and water, as shown by a 2016 systematic review published in Critical Reviews in Toxicology. While one 2017 study is frequently cited to support these scary-sounding claims, higher quality studies disprove it. Aluminum levels detected in breast tumors are the same as those in normal tissue. Rest assured, if you like these types of antiperspirants (I’m an Old Spice gal, myself!), you are not putting your health at risk.

Myth: Underwire bras cause breast cancer.

This claim is based on the notion that underwires interfere with the circulation of the lymphatic system, causing toxins to build up in lymph nodes and breast tissue, leading to cancer.

Reality: While this myth often runs rampant online, there’s no credible evidence behind it.

Just like with antiperspirants, the idea of “toxins” accumulating in breast tissue is implausible based on how our bodies work.Your immune and lymphatic systems are complex and well-regulated; they are not impacted by wearing an underwire bra, even one that might be tight. There is no scientific basis to support this idea. All major and credible health organizations, including the American Cancer Society and the National Cancer Institute have concluded that there is no data that shows a link between bras (of any type) and an increased risk of breast cancer.

Myth: Sugar causes or feeds breast cancer.

This belief stems from a feature of certain cancers, a phenomenon called the Warburg effect, where cancer cells consume glucose (sugar) at a high rate due to metabolic demands. In fact, PET imaging (positron emission tomography) is a technology that leverages this Warburg effect for cancer screening.

Reality: There is no evidence that eating sugar (naturally-occurring or added) causes or accelerates the spread of cancer.

All cells need glucose to function, not just cancer cells. PET scans use a radioactive form of glucose that labels areas in the body that consume glucose quickly. This helps detect cancer cells, which will “light up” on a PET scan. But many healthy cell types also use glucose at high rates, and they light up on PET scans, too. The fact that PET scans use glucose doesn’t mean eating sugar makes cancer cells grow faster. In reality, there is no direct link between eating sugar and cancer growth.

That being said, sugar consumption is sometimes conflated with obesity, which is a risk factor for breast cancer, particularly after menopause. The goal should always be eating a nutritious diet and maintaining a healthy weight, but sugar also doesn’t cause obesity. In fact, many foods that contain sugar are nutritious components of a healthy diet. You do not need to avoid sugar for fear of “feeding cancer.”

Myth: Only people with a family history are at risk of breast cancer.

Some people think that if they have no history of breast cancer in their family, they aren’t at risk. This can create a false sense of security, and cause them to be less diligent about preventative breast cancer screenings or ignore symptoms or warning signs of breast cancers.

While certain gene mutations like BRCA1 and BRCA2, genes that repair DNA damage, can increase the risk of developing some cancers (breast included), inherited mutations only account for 5-10 percent of breast cancers. Another 15-20 percent occur more often in certain families without known gene mutations. The biggest risk factors for breast cancer are aging (true of all cancers), being female, and lifestyle factors (smoking, excess alcohol consumption, poor diet, inactivity). That’s why awareness and routine screenings are important for everyone, regardless of their family history.

Myth: Herbal and alternative remedies can cure breast cancer.

Breast cancer is a scary diagnosis and the treatments can also sound scary. This causes some people to explore alternative options such as herbal remedies or supplements. But be aware, this can have serious consequences.

Reality: there is no evidence that alternative remedies can cure breast cancer.

We are constantly studying new and emerging cancer treatments. If there were options out there that we knew worked, they would be incorporated into evidence-based treatment plans. For breast cancer, surgery, radiation, chemotherapy, and immunotherapies have proven to be effective treatments and cures.

Today, the vast majority of breast cancers are survivable if you seek proven treatments after early detection. The five-year survival rate is over 90 percent. However, this may not be the case if you opt for unproven alternatives. The five-year survival rate plummets to 58.1 percent and breast cancer patients have a 5.7-fold increased risk of death when using alternative treatments instead of proven methods, per a 2017 article in the Journal of the National Cancer Institute.

Some non-medical interventions may be used for symptom management, addressing discomfort, or improving quality of life. But these should never replace proven cancer treatments, and anything, particularly supplements you might consume, should always be reviewed with your healthcare team, as these can contain substances that can interact and interfere with treatments.

Myth: Mammograms and radiation exposure cause breast cancer.

Many people are understandably concerned that certain types of radiation can cause breast cancer. As a result, some people avoid mammograms because of undue fears about the accompanying radiation exposure.

Reality: Mammograms, like other imaging technologies, do involve low dose radiation, but the amount is tiny.

A mammogram uses 0.4 millisieverts (mSv) of radiation. You’re exposed to 10 times that level every single year of your life simply by living on Earth. And a flight from New York to California comes with 10 percent of the amount of radiation exposure you get during a mammogram. (Frequent fliers also need not be concerned.)

Not only do regular mammograms not contribute to breast cancer, but their role in screening for breast cancer is huge. Mammograms are the best early detection method and drastically improve survival. Point being, don’t opt out of mammograms or seek unproven alternatives like thermography.

Navigating breast cancer can feel daunting. It’s worse when you’re bombarded by misinformation and pseudoscience myths. Not only are these claims misleading, but they can also prevent people from seeking appropriate diagnosis and treatment, and even end up causing serious harm.

When it comes to breast cancer, many things are out of your control, but you can take some steps to reduce your risk. Early detection, a healthy lifestyle, and proven medical care are the best tools to prevent breast cancer. But fighting breast cancer is also about arming yourself with accurate information. Because when it comes to breast cancer, facts save lives.

Andrea Love, PhD, is a biomedical scientist and award-winning science communicator. She has over a decade and a half of expertise in infectious diseases, cancer, and immunology. She excels at translating complex scientific concepts and data for broad audiences. Outside of her career, she is the founder of the science communication organization ImmunoLogic and is the executive director of the American Lyme Disease Foundation. Dr. Love is a PS Council member.