Oncologist debunks popular cancer myths that mislead people online

In today’s digital world, people have access to more health information than ever before. But the same internet that helps us learn can also mislead us. When it comes to something as serious as cancer, false claims on social media can do real harm. Bengaluru-based oncologist Dr Vinayak Maka from Ramaiah Institute of Oncosciences, Ramaiah Memorial Hospital, says misinformation about cancer spreads faster than awareness. He explains that people often believe online “tips” or home remedies that sound convincing but have no scientific proof. These myths can delay proper treatment, harm patients’ health, and even cost lives.

Dr Maka shares five common cancer myths that people must stop believing, and explains what the real science says.

Myth 1: Sunscreen causes cancer

Some social media influencers claim that sunscreen itself causes cancer. This is completely false. According to Dr Maka, sunscreen protects the skin from ultraviolet (UV) radiation, which is a known cause of skin cancer. UV rays damage the DNA in skin cells, and over time, this can lead to cancer. Sunscreen acts as a shield that blocks or absorbs these harmful rays.

When people stop using sunscreen out of fear, they actually increase their cancer risk. “UV radiation is an established human carcinogen,” says Dr Maka. “Sunscreen, when used along with other preventive measures like hats and shade, helps prevent skin cancer.”

So, instead of avoiding sunscreen, people should use it regularly—especially when stepping outdoors. Always pick a broad-spectrum sunscreen with SPF 30 or higher, and reapply it every two hours.

Myth 2: Sugar feeds cancer, so it must be completely avoided

This is one of the most common myths online. Many posts and videos claim that “sugar feeds cancer” and that cutting out all sugar can stop cancer from growing. Dr Maka says this idea is misleading and dangerous.

Cancer cells, like all other cells in our body, need glucose (a form of sugar) for energy. But that does not mean sugar “feeds” cancer more than it feeds healthy cells. Cancer cells grow uncontrollably because of genetic mutations, not because you ate sweets.

The real problem is too much added sugar, which can lead to obesity—a known risk factor for several types of cancer. Completely cutting off sugar can harm patients undergoing treatment because it often leads to weight loss and weakness when their bodies need energy the most.

“The body needs a balanced diet,” Dr Maka explains. “Fruits, grains, and dairy naturally contain sugars that provide energy and essential nutrients. Avoiding them can actually make recovery harder.” Patients should focus on a balanced diet recommended by their oncologist or nutritionist, rather than following extreme online diets.

Myth 3: Alkaline diets can cure or prevent cancer

Some online “wellness” coaches promote alkaline diets or drinks—like turmeric shots, neem water, or apple cider vinegar—claiming they can change the body’s pH and make it impossible for cancer to grow. This idea is scientifically false.

Dr Maka clarifies that the body naturally maintains its pH through complex internal systems, no matter what you eat. Your blood stays slightly alkaline, and food cannot change that balance. “There’s no evidence that alkaline diets can prevent or cure cancer,” he says.

While some of these foods—like turmeric—have general health benefits, they are not cancer treatments. People who replace proven medical therapies with such untested diets put their lives at serious risk.

Myth 4: Natural remedies can replace chemotherapy

Many viral videos claim that natural substances, such as dandelion root, can kill cancer cells. Dr Maka warns that while lab research may show some potential, no proper clinical trials have proven these claims in humans.

Chemotherapy, though it has side effects, remains one of the most effective and well-tested cancer treatments. “Lab studies are not the same as patient results,” says Dr Maka. “Something that works in a petri dish doesn’t always work inside the human body.”

Replacing chemotherapy or radiation with unverified “natural” treatments can allow the cancer to spread faster and reduce the chance of survival. Patients should always consult their oncologist before trying any alternative remedy.

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Why misinformation is dangerous

Social media often spreads health misinformation because people are drawn to easy solutions. Videos with titles like “Cure cancer naturally in 10 days” get millions of views because they sound hopeful. But Dr Maka says hope should be guided by evidence, not trends.

He emphasizes that people should never base medical decisions on unverified online posts or influencers. “Always check the source,” he advises. “If it’s not coming from a qualified doctor, a cancer research institute, or a peer-reviewed study, it should not be trusted.”

Cancer treatment has improved greatly in recent years with targeted therapy, immunotherapy, and better diagnostics. But these advancements work only when patients get timely, evidence-based care. Believing in false cures or miracle diets can delay that care, leading to worse outcomes.

The right way forward

Dr Maka urges everyone—patients, caregivers, and the public—to think critically about what they see online. It’s fine to learn about health through the internet, but people must rely on verified medical websites, government health portals, or their own doctors for accurate information.

When in doubt, ask your oncologist instead of trusting social media influencers. Cancer treatment requires teamwork between doctors and patients, built on trust and truth. “Medical science, not viral trends, saves lives,” Dr Maka reminds.

In the end, awareness is the best protection. Knowing the truth about cancer myths can prevent fear, misinformation, and harmful choices. Science-backed knowledge, regular check-ups, and timely treatment are the real weapons in the fight against cancer—not miracle claims on social media.