6 Myths About Cancer Risk Oncologists Wish You'd Stop Believing

Reviewed by Dietitian Jessica Ball, M.S., RD

Key Points

• Sugar does not feed cancer. Balanced nutrition is key for treatment and recovery.

• Most cancers are not inherited, and lifestyle changes and screenings are critical for prevention.

• Evidence-based treatments are safest. Herbal remedies and alkaline diets cannot cure cancer.

Cancer is a diagnosis that can carry an enormous amount of fear, and is often associated with serious and, in some cases, even terminal illness. But like so many things, what we hear from a friend, family member or on the internet isn't always true. Some of the most popular beliefs about cancer are not rooted in science. Ahead, oncologists set the record straight and share six myths about cancer risk they wish you'd stop believing and (hopefully) put your mind more at ease in the process.

Myth #1: Sugar Feeds Cancer

"Almost on a daily basis I have at least one patient tell me: I cut out all sugar because everyone knows sugar feeds cancer," says oncologist David Greenberg, MD, FACP . But he says this is simply not true. Sugar does not 'feed' cancer or cause cancer to grow faster.

So where did this myth come from? "I believe this myth originated from the fact that many cancer patients receive PET scans, and PET scans act by tagging your sugar (glucose) with a nuclear compound called FDG," he says. He explains that while it's true that malignant cells utilize sugar more rapidly, and allow PET scans to detect faster growing cancer cells, it has nothing to do with how cancer grows in your body. And there is no data to support that excess sugar intake will make your cancer worse, he says.

Oncologist Sagun Shrestha, M.D.,  agrees and says, "While cancer cells do use glucose, so do all normal cells in the body. There is no strong clinical evidence showing that eliminating sugar can stop or slow cancer growth."

This myth can also cause harm to patients. Oncologist Reena Vora, MD,  explains "This myth can lead patients to adopt extreme, nutritionally-deficient diets at a time when adequate nutrition is critical for treatment tolerance and recovery." It can also be worrisome as those with cancer are already at risk for losing weight, adds Shrestha.

Oncologists agree that overdoing it in the added sugar department isn't the best idea, either. Keep foods and drinks with added sugar to a minimum and focus on including a balanced mix of whole foods in your eating pattern.

Myth #2: Deodorant Causes Cancer

Ever heard applying deodorant may cause breast cancer? This is one myth oncologists wish you'd stop believing because it's not true—and you might start to get a little stinky without it.

"Studies looking at large groups of people have not found a clear link between deodorant or antiperspirant use and breast cancer," says Vora. This held true even when researchers looked at antiperspirant, deodorant or at applying it within an hour of shaving—all common myths.

Voha says the myth came from lab studies that showed aluminum salts affected breast epithelial cells at high concentrations. However, large studies have not consistently found a connection between real-world antiperspirant use and breast cancer risk.

This myth can cause unnecessary anxiety and lead patients to avoid basic hygiene products, she adds. "More importantly, it distracts from evidence-based breast cancer risk reduction strategies such as maintaining a healthy weight, exercising, limiting alcohol and adhering to screening guidelines."

Myth #3: Cancer is Mostly Genetic

Many people think, if cancer runs in your family, it likely will impact you too. But oncologists say this is just a myth. "Only a small percentage of cancers are inherited. Even in cancers with stronger genetic links, most risk still comes from non-genetic factors," says Voha.

Shrestha agrees: "Most cancers are not inherited. In fact, the majority are considered sporadic and are influenced by environmental and lifestyle factors. This misconception can lead people to skip recommended screenings, which are critical for early detection."

Research also backs this up. "An estimated 42% of all cancers diagnosed in the United States are attributable to potentially modifiable risk factors," says Voha. Diet, smoking and alcohol use all are modifiable risk factors that play a significant role in cancer risk. "Even individuals with hereditary cancer syndromes benefit from lifestyle modifications and enhanced screening," she adds.

Myth #4: Avoid Soy-Based Foods When Diagnosed with Cancer

"I need to avoid soy based foods now that I have been diagnosed with breast cancer," is another myth Greenberg hears often.

The reason for it? Soy foods like tofu, edamame and soy milk contain phytoestrogens, a weak estrogen, which is likely where the misconception came from, he says. "The current evidence shows no correlation between soy intake and increased breast cancer risk. In fact, there are studies that actually suggest a lower risk of breast cancer and breast cancer recurrence when soy foods are incorporated into your diet."

So, no need to fear soy-based foods, just consume them in moderation, Greenberg says.

Myth #5: Natural and Herbal Remedies Can Cure Cancer

When you or someone you love receives a cancer diagnosis, the first thing you may do is to start searching for a cure. And in that search, you may come across natural or herbal remedies promising exactly that. Unfortunately for many hopefuls, oncologists say, these types of remedies can not cure cancer.

"There is no high-quality evidence showing that herbal or "natural" treatments can cure cancer," says Shrestha. "In some cases, these products can interfere with standard treatments or delay care. Evidence-based therapies remain the safest and most effective approach." However, if a patient is interested in starting one alongside their treatment, it's best to first consult with their physician to avoid any potential interactions, she says.

Myth #6: Increasing Alkaline In My Diet Will Fight Cancer

Heard of the alkaline diet or seen claims that alkaline foods are beneficial to your health? The idea that boosting your body's alkalinity can fight or prevent cancer, is a myth Greenberg hopes to put to rest.

"There is no evidence to support increasing the pH in the body will help your body fight cancer or prevent it," he says. "The body has its own very complex system that it uses to balance your pH appropriately. Guzzling liters of alkaline water will do nothing to affect your cancer risk, but it will make you urinate more often."

Better Ways to Help Lower Cancer Risk

Stop believing everything you hear about cancer risk because scary-sounding information may just be myths. Here, oncologists share evidence-backed  ways to help lower cancer risk.

• Eat a Well-Balanced Diet: The best way to decrease your cancer risk is to follow a well balanced diet, rich in vegetables, fruits, whole grains  and lean proteins , says Greenberg. Limit ultra-processed foods  and drinks high in added sugar.

• Avoid Tobacco: "Avoiding tobacco is the single most important step, as it is linked to a large proportion of cancer deaths", says Shrestha.

• Maintain a Healthy Weight: Staying at a healthy weight and remaining physically active is important. Excess weight can cause inflammation and chronic disease—both of which indirectly raise cancer risk.

• Limit Red and Processed Meat: Try to limit red meat  and grilled meats  to no more than 4 times per month, says Greenberg. Also avoid or minimize ultra-processed meats  like cured meats as this is a known carcinogen, he adds.

• Limit Alcohol Intake: Alcohol is also a known carcinogen, so consider avoiding or limiting alcohol , says Greenberg.

Questions to Ask Your Doctor About Cancer Risk

It's natural to have questions about cancer risk. Here are ones oncologists recommend you should be asking.

Start by finding out which cancer screenings are recommended for you based on your health history, says Shrestha. Also ask, which lifestyle changes would be most beneficial for you to adopt. If shifting your diet is on your list, meet with a registered dietitian nutritionist to help to get started on a realistic healthy eating plan. Voha provides a list of questions to take to your next appointment:

• Am I up to date on my screenings?

• What lifestyle changes would help me the most?

• Do I need any vaccines to lower my cancer risk?

• I heard something about cancer risk  (insert topic) — is it actually true?

• Are there any preventive options I should consider?

• Based on my health history, what cancers should I be thinking about?

Our Expert Take

The internet has given us access to an endless amount of information—but not all of it is accurate or backed by science. The six cancer risk myths oncologists wish you'd stop believing are: that sugar feeds cancer, that deodorant causes cancer, that cancer is mostly genetic, that soy should be avoided after a diagnosis, that natural and herb remedies can cure cancer and that an alkaline diet can fight cancer.

Instead focus on what the studies actually support: eating a well-balanced diet rich in fruits, veggies, whole grains and lean proteins. Limit alcohol, avoid tobacco, reduce red and processed meats, stay active and maintain a healthy weight.

"Overall, reducing cancer risk comes down to focusing on evidence-based strategies rather than misinformation. Understanding what truly matters can help patients make informed decisions and avoid unnecessary fear", says Shrestha.

Read the original article on EatingWell