Let’s get to the bottom of it – 7 common cancer myths, unpicked

This article was originally published in January 2022. We updated it on 19 July 2023. On 20 July 2023, we added explainers on how the International Agency for Research on Cancer classifies non-ionising radio frequency radiation and how we evaluate research.

Google the word ‘cancer’ – or search for it on social media – and you’ll see millions of results.   

But the internet isn’t always reliable. Some of those results will include useful, accurate information, but others will be inaccurate, or even dangerously misleading.  

It can often be hard to distinguish fact from fiction. Increasingly, we’re surrounded by fake news, false claims and unproven theories that look and sound perfectly plausible. And while they may seem to point to answers, they can actually take us further from the truth.   

Misinformation is not supported by scientific research or evidence. It can lead to needless worry and affect our decisions when it comes to cancer prevention, and even cancer treatment.  

So, from 5G to baking soda, we want to set the record straight on 7 commonly asked questions about cancer that are often rooted in misinformation. Read on for our July 2023 update.

1. Can 5G or wifi cause cancer?  

Evaluating the best scientific evidence, there are no good explanations for how 5G or wifi could cause cancer.  

You may have heard the myth that 5G networks emit radiation that can damage our DNA and cause cancer. But when it comes to radiation, the amount of energy released is what matters.  

High energy radiation (often called ionising radiation), such as UV rays from the sun, releases enough energy to damage DNA. But both 4G and 5G networks transmit radio frequency radiation (radio waves), which is very weak (non-ionising). This means that it does not have enough energy to damage DNA, so there is no direct way it can cause cancer.  

Mobile phones, phone masts and wifi also rely on the same non-ionising radiation. Radio waves produced by wifi are even weaker than those produced by mobile phones, and are well within the international guidelines that the UK adheres to.  

You may also have seen alarming headlines that seem to link the radiation from mobile phones to cancer. But these are often based on studies carried out on cells or rats in a lab. Typically, they use much higher doses of radiation than those emitted by mobile phones. They also expose cells to those big doses for much longer than people use their phones in real life.    

Several large-scale studies in people have been conducted over the years and have found no clear evidence that mobile phones or wifi cause cancer. Mobile phone use has risen dramatically over the last few decades, with billions of people now using them around the world, and yet we’re not seeing such a significant rise in the rates of conditions such as brain, thyroid or salivary cancers. 

As 5G, 4G, mobile phones and wifi are still relatively new technologies, research is ongoing. We can’t completely rule out long-term effects and we will continue to monitor the evidence.

But, overall, there’s no good evidence of a link with cancer.  

2. Do microwaves cause cancer?  

Just like the radio waves used by mobile phones, microwave radiation is non-ionising.  

This means microwave radiation is too weak to damage DNA and can’t directly cause cancer.   

Despite some common misconceptions, microwaves do not make your food radioactive and it’s safe to stand in front of the microwave oven when it’s on.  

When it comes to cancer risk, it’s what you eat, not how you heat it up, that matters.   

To reduce your cancer risk, a healthy, balanced diet is more important than individual foods. This includes eating fruit and vegetables, wholegrains (like brown rice or brown pasta) and healthy sources of protein (like beans, lentils or fresh chicken), whilst reducing your intake of processed and red meat, and foods high in sugar, fat and salt.  

3. Can an acidic diet cause cancer and can an alkaline diet cure cancer?  

Our kidneys keep our pH levels within a very strict and narrow healthy range. What you eat can’t change this for any meaningful amount of time. Any extra acid or alkali from your food comes out in your pee. 

So, sticking to a strict alkaline diet won’t prevent or cure cancer, and eating acidic foods won’t cause cancer.  

Lab research may tell us some things, but it doesn’t reflect how cancer cells behave in the body, which is much more complex. And, although it’s true that cancer cells can’t live in a very alkaline environment, neither can any other cells in our body. 

A healthy balanced diet, with lots of fruit and vegetables, plenty of wholegrains and healthy sources of protein, can help to reduce our risk of cancer and keep us a healthy weight. But, put simply, there’s no good evidence to prove that our diet can change our whole body’s pH, or that a diet of a certain pH has any impact on cancer.  

4. Do underwired bras or using deodorant cause cancer?

Rumours about deodorants and underwired bras have been going around for several years, particularly when it comes to breast cancer.   

However, there’s no sound scientific evidence that using deodorants, antiperspirants or body sprays causes any type of cancer. Some myths claim that aluminium, the active ingredient in most of these products causes cancer, but a review of the evidence has disputed this.  

It’s also worth pointing out that all cosmetics sold in the UK are tightly regulated and must be shown to be safe. And while it is true that the NHS tells people not to use spray deodorants before a breast screening, this is because it can affect the screening results, not because it is harmful. 

Similar claims around bras and breast cancer aren’t supported either. Wearing any kind of bra, including underwired bras, does not increase your risk of breast cancer. You might have heard that underwired bras restrict the circulation of lymph fluid, but this isn’t the case. In reality, lymph fluid travels up and into the underarm lymph nodes, not towards the underwire. 

While many factors can influence breast cancer risk, going braless isn’t one of them.   

The bottom line: whether you choose to wear a bra or not, you can do so without worrying about an increased risk of cancer. 

5. Does the cure for cancer already exist? 

Animals were developing cancer long before humans inhabited the earth, and the world’s oldest documented case of cancer in humans is from ancient Egypt in 1500 BC.   

So, some people may assume that, after all this time, someone must have found a cure. 

But the reality is that cancer is extremely complex. It comprises over 200 different diseases, and each one presents its own challenge to treat. So, despite decades of amazing research, there is no ‘silver bullet’ that will cure all cancers.  

But we have made real progress. In the charity’s 120-year history, we’ve significantly improved outcomes for people with cancer. Even in the last 40 years, survival has doubled. We’ve contributed to that by researching more effective and gentle treatments, helping to improve diagnostic techniques and campaigning for policy change. And our goal is to improve survival of those diagnosed with cancer to three in four by 2034.  

Hand in hand with the idea of a ‘silver bullet’ cure is the belief that governments, the pharmaceutical industry and even charities are hiding the cure for cancer because they make money off existing treatments.  

We understand that there are some frustrations around transparency within the pharmaceutical industry. We advocate for regulators, health technology assessment (HTA) bodies, and pharmaceutical companies to make sure that effective drugs are made available quickly and at a fair price to the NHS. That said, it’s important to remember that developing and trialling new drugs costs a lot of money, which companies need to recoup.  

And the reality is that finding a highly effective therapy would actually guarantee huge worldwide sales for any pharmaceutical company.  

What’s more, charities and government-funded scientists are free to investigate promising treatments without a profit motive.   

Finally, it’s worth remembering that we’re all human. Cancer can affect anyone, from politicians to big pharma executives. We’re all working towards a common goal – to help beat it.  

Want to find out more? Check out our podcast below: 

6. Does cancer treatment kill faster than it helps?  

This kind of question tends to arise in relation to chemotherapy, as the side effects can be particularly gruelling.

The important thing to remember is that doctors offer people cancer treatments to give them the best chance of survival.

Side effects happen because cancer cells can be very similar to our healthy cells. That means treatments like chemotherapies, which are designed to kill cancer cells, can harm our healthy cells too.

But every licensed treatment has been through rigorous clinical trials to ensure it’s safe and effective, and to make sure we understand its possible side effects.  

Overall, chemotherapy and other cancer drugs have a very important part to play in cancer treatment. In some cases, they help to cure the disease. In others, they give people more precious time to spend with their loved ones.  

And the treatments keep getting better. Take children’s and young people’s cancer. In the 1970s, just over a third of children diagnosed with cancer in Great Britain (England, Scotland and Wales) survived for 10 years or more. Now, more than 8 in 10 children and young people in the UK (aged 0 to 24) do so. This huge improvement in outcomes has been made possible by all the work that has gone into developing treatments, including chemotherapy.  

So, we’ve come a long way since the 1970s, but we’re not done yet. Treatment for children and young people can often have long-lasting, damaging side-effects. Our increasing understanding of the biology of cancer has already led to significant improvements to the way we use chemotherapy in this group. And researchers are always looking to reduce the toxicity of these treatments.   

But sadly, treatment isn’t always successful. We know that it’s very difficult to treat late-stage cancer that has spread throughout the body. And while treatment can provide relief from symptoms and prolong life, it’s very difficult to find a cure for very advanced cancers.  

We know that side effects exist, and it’s important to talk about them as part of your cancer journey. We also understand that we still have a long way to go until we have effective, kinder treatments for all types of cancer. It’s something we’re striving for every day. 

7. Is cancer a fungus and baking soda the cure?   

We don’t know exactly where it came from, but the myth that cancer is a fungus (particularly the common fungus candida) is a persistent one.  

Thankfully, this is easy to bust. Scientists have proved that cancer begins due to faults (mutations) within our bodies’ own cells. These mutations cause cells to grow in an uncontrolled way. Lots of different things can trigger cancerous mutations, but the important thing is that they always happen within our own cells. And, because scientists can easily distinguish between human and fungal cells, it’s clear that cancer isn’t a fungus.

But this myth doesn’t stop there. It goes on to claim that cancer can be eliminated using baking soda (sodium bicarbonate). Oddly, though, this isn’t even the treatment used to treat proven fungal infections.

Some studies suggest that sodium bicarbonate can affect cancers transplanted into mice or cells grown in the lab, by balancing out the acidity in the area immediately surrounding a tumour. But, as we covered earlier, changing our body’s pH level isn’t so simple.

What’s more, high doses of sodium bicarbonate are poisonous and can lead to very serious consequences. There are no published clinical trials testing it as a treatment for cancer, which means there’s no evidence to support using it.