Hoax emails and internet memes are misleading and confusing - don't pass them on.
About a decade ago – back in the dark ages before social media took off – various versions of an email started circulating.
Purporting to be a “Cancer Update from John Hopkins Hospital” in the US, the messages claim to describe the properties of cancer and point to a number of ways to apparently prevent the disease, including cutting out all sugar and avoiding plastics.
The origins of these messages are unknown, but they are a confusing mix of fact and fantasy that could potentially mislead people and cause worry.
The first thing to say is that these emails are hoaxes.
Understandably, the real Johns Hopkins Medical Centre is unimpressed by the efforts to spread misinformation in its name and has issued a long explanation and rebuttal of the claims made in these emails.
They say, “An email falsely attributed to Johns Hopkins describing properties of cancer cells and suggesting prevention strategies has begun circulating the Internet. Johns Hopkins did not publish the email entitled ‘Cancer Update from Johns Hopkins’ nor do we endorse its contents. Another hoax email that has been circulating regarding plastic containers, bottles and plastic wrap claiming that heat releases dioxins which cause cancer also was not published by Johns Hopkins.”
They also advise sending a link to their page to anyone who forwards you one of these emails, to point out it is a hoax and not official in any way.
But, these emails do raise some common misconceptions about cancer and its treatment, so we thought we should address some of them directly.
So what’s in it?
Let’s take a closer look at some of the claims made in the email and unpick the real science behind them.
- Claims 1 and 2: Everyone has cancer cells in the body
- Claim 3: The immune system destroys cancer cells
- Claim 4: Cancer is due to nutritional deficiencies
- Claim 5: Diet and supplements strengthen the immune system
- Claims 6-9: Cancer treatment has harmful effects
- Claim 10: Cancer treatment causes cells to become resistant to therapy
- Claim 11: ‘Starving’ cancer can treat it, plus things that ‘feed’ cancer
- Bonus claim: Cancer risk from plastics
Email claim 1: “Every person has cancer cells in the body. These cancer cells do not show up in the standard tests until they have multiplied to a few billion. When doctors tell cancer patients that there are no more cancer cells in their bodies after treatment, it just means the tests are unable to detect the cancer cells because they have not reached the detectable size.”
Email claim 2: “Cancer cells occur between six to more than 10 times in a person’s lifetime.”
The facts: Cancer cells develop from healthy cells in the body, as a result of damage to their genes (DNA). Our cells develop genetic mistakes all the time, mostly caused by accidental damage resulting from the normal processes of life within our cells but also due to things around us. So it’s true that we all carry a certain number of damaged or faulty cells, but these are usually destroyed by the immune system and don’t ever grow into a cancer.
A healthy cell has to develop several genetic faults before it becomes a cancer cell, and then these faulty cells have to survive and grow into a tumour, picking up more mistakes to become a malignant cancer that can start spreading through the body. There’s much more about this on our website.
It’s true that at the moment it’s impossible to detect tiny clusters of cancer cells less than a couple of millimetres in diameter. But what’s not clear at all is whether the presence of these rogue clumps of cells is relevant to a person’s health.
Everyone’s body probably contains tiny clusters of faulty cells that will never grow into a harmful cancer. These may even grow large enough to be detected by a scan or other tests. But being able to spot these very small tumours can also lead to over-diagnosis – treating people for tumours that would never have caused them a problem in their lifetime.
Detecting very small clusters of cancer cells that remain after treatment is certainly a challenge. But, in some cases cancer can be completely cured. We know this because many thousands of people are successfully treated for cancer and go on to live long and happy lives.
So the fact that small groups of cancer cells cannot be detected doesn’t mean that they are always still hiding there or are dangerous.
But, we do know that in other cases cancer cells can remain in the body after therapy – this is why cancers can come back after treatment, even many years later, and can be resistant to treatment.
Working out how to detect these recurrences early and treat them effectively is a major challenge, and it’s one we’re working on.
The facts: As mentioned above, the immune system will generally recognise damaged or faulty cells and destroy them. But a poorly performing immune system isn’t usually a major cause of cancer, except in rare situations such as after an organ transplant.
Rather, cancers start growing when they develop further genetic faults that enable them to ‘hide’ from the immune system. There’s also evidence that tumours can manipulate the environment around them to prevent immune cells attacking the cancer cells. It doesn’t matter how good your immune system is if it can’t see what it’s meant to be fighting or has had its weapons taken away.
There’s a huge amount of research under way from our scientists and others around the world aimed at ‘unmasking’ cancer cells so the immune system can see them, including exciting new immunotherapy drugs that we’ve written about before.
The facts: Not true. There’s no evidence to suggest that cancer is caused by “multiple nutritional deficiencies”, whatever they are.
But we do know that cancer risk is a complex interplay of age, lifestyle (including tobacco, alcohol, diet, weight, sun exposure, physical activity and more), environment and genetics – plus a dose of either random chance or bad luck, depending on your perspective.
There’s lots more information about the causes of cancer on our website.
The facts: Given that “multiple nutritional deficiencies” are a red herring when it comes to cancer, this claim isn’t accurate either. And there’s evidence that popping supplements may be more harmful than helpful.
There’s a huge amount of nonsense written all over the internet about ‘boosting the immune system’ with various restrictive diets and supplements, and virtually no evidence to suggest that any of them work. There’s an impressively lengthy blog post here explaining how the immune system works and why ‘boosting’ it with certain pills or supplements is a myth. These posts from Science Or Not? and Science Based Medicine are also useful.
That’s not to say that diet is totally unimportant. Of course, eating a balanced diet rich in fruit and veg will help to keep you healthy and reduce cancer risk, as will doing regular activity and stopping smoking. We’ve also written this post about what to eat while being treated for cancer. But claims that unproven fad diets or supplements that ‘strengthen the immune system’ are the key to getting rid of cancer are overly simplistic and misleading.
Email claim 6: “Chemotherapy involves poisoning the rapidly-growing cancer cells and also destroys rapidly-growing healthy cells in the bone marrow, gastro-intestinal tract etc, and can cause organ damage, like liver, kidneys, heart, lungs etc.”
Email claim 7: “Radiation while destroying cancer cells also burns, scars and damages healthy cells, tissues and organs.”
Email claim 8: “Initial treatment with chemotherapy and radiation will often reduce tumour size. However prolonged use of chemotherapy and radiation do not result in more tumour destruction.”
Email claim 9: “When the body has too much toxic burden from chemotherapy and radiation the immune system is either compromised or destroyed, hence the person can succumb to various kinds of infections and complications.”
The facts: It’s no big secret that chemotherapy and radiotherapy damage and kill healthy cells as well as cancerous ones – that’s why cancer treatment has side effects. It’s also true that cancer treatment can affect the immune system, increasing the risk of infection and other complications.
But getting rid of a life-threatening cancer is obviously very important, and these treatments can be very effective.
Claim 8 is incorrect – in some cases chemotherapy or radiotherapy can completely eradicate tumours, rather than just reducing them in size. But the problem is that some cancer cells can be resistant to treatment and continue to grow.
The risks and side effects of treatment are something that any doctor will discuss at length with their patients. Different treatments have different side effects, and we’ve got extensive information about these on our website.
The fact remains that many thousands of cancer patients are successfully treated every year in the UK using surgery, radiotherapy and chemotherapy. Half of all people diagnosed today will survive at least ten years, and many of them will survive much, much longer – effectively being cured.
But these treatments are not perfect, and we are continuing to research more effective, kinder therapies including more precisely-targeted radiotherapy, drugs targeted to faulty molecules inside cancer cells and immunotherapy, as well as investigating ways to reduce the side effects of treatment.
The facts: It’s becoming increasingly clear that cancer is almost like a ‘rogue organism’, changing and evolving within the body as it grows and spreads. We’ve written extensively about the work our scientists are doing to unpick the complex pathways of tumour evolution and heterogeneity (the genetic ‘patchwork’ in cancers) – for example here, here, here, here and here.
It’s well known that tumours can evolve resistance to drugs and radiotherapy, and it’s a major challenge for treating advanced cancer. But what’s less clear is whether treatment itself is causing the genetic changes that enable cancer cells to evade treatment, or if these changes are already present when the cancer first starts. In all likelihood, it’s probably both.
Understanding the origins of drug and radiotherapy resistance is a key focus for our researchers and others around the world. As we highlight in this post, understanding the genetic changes that drive tumour evolution will lead to smarter approaches for treatment that target all the cancer cells in the body, not just some of them.
There is a small risk that cancer surgery can release tumour cells into the bloodstream, which might enable it to spread. But the fact that surgery cures more people of cancer than any other treatment suggests that this is not a common occurrence.
Again, it’s important to remember that thousands of patients are successfully treated using these therapies and survival is climbing year on year. Despite their known flaws, these treatments are the best weapons we have against cancer.
The facts: The only way to ‘starve’ cancer cells is to never eat anything at all. It’s biologically impossible to selectively send nutrients only to the healthy cells in your body rather than the cancer cells, as all the cells in the body – whether cancerous or healthy – get their nutrition and oxygen from the same place: the bloodstream.
That said, cancer cells do process these nutrients differently from healthy cells due to the speed at which they are growing and multiplying. Researchers are investigating these differences in order to find new approaches to treatment, but there’s no good evidence that fad diets or restricting particular foods can ‘starve’ cancer in the body. There’s more evidence-based advice about what to eat when you’re being treated for cancer here on the blog.
Some versions of the hoax emails specifically mention a few things that cancer cells supposedly ‘feed on’:
- Sugar: We’ve explained the common misconceptions about sugar and cancer here.
- Milk: There’s conflicting evidence about whether milk can increase the risk of certain types of cancer, but at the moment there isn’t any good evidence to suggest that milk is a major risk factor for any type of cancer. In fact, it may even decrease the risk of bowel cancer.
- An ‘acidic environment’: The idea that cancer thrives in an ‘acidic environment’ that can be countered by an ‘alkaline diet’ is a myth. Read more here.
- Meat: There’s good evidence that eating a lot of red and processed meat can increase the risk of certain types of cancer (read more on our website) but it’s not true to say that it ‘feeds’ cancer in the body.
- Caffeine (particularly coffee): Coffee appears regularly in the news for its apparent ability to simultaneously both cause and prevent cancer and, as we explain in this blog post, the evidence for benefits or risks is mixed. Overall, there’s no evidence that coffee ‘feeds’ cancer, increases the risk of developing any type of cancer, or increases the risk of dying from the disease. And it’s worth pointing out that the alternative cuppa suggested in the email – green tea – contains caffeine too.
- “Anger, unforgiveness and bitterness”: A negative or angry mental attitude cannot fuel the growth of cancer, any more than a positive attitude can stop it – there’s no evidence that positive thinking can affect cancer growth or survival, although it can help patients feel more in control of their illness. Much is written about how patients should always ‘stay positive’ and ‘fight’ the disease. But while some people may find this language helpful, for others it may fuel feelings of guilt and anxiety if they don’t feel able to be upbeat all the time. The American Cancer Society has more information about attitudes and cancer, and we’ve also written about the importance of addressing depression in patients. “Learn to relax and enjoy life”, as the email suggests, is a fine piece of advice, and one we could all heed. But it won’t cure cancer.
The email also recommends the following alternative treatments for cancer:
- Oxygen therapy: There are several different types of oxygen therapy touted for cancer treatment, including ozone therapy, hydrogen peroxide, and hyperbaric oxygen. There’s no evidence that ozone or hydrogen peroxide therapy has any effect on cancer growth in patients, and these treatments can also be harmful or even fatal – more here and here. Hyperbaric oxygen treatment is being investigated in clinical trials – including our own HOPON study – to see if it can reduce side effects of radiotherapy such as bone damage and tissue swelling (lymphoedema). But, there isn’t any good evidence at the moment that it is effective at treating cancer itself.
- Nutritional supplements: At the moment there isn’t reliable evidence to show that any particular dietary supplements can help prevent or treat cancer. Furthermore, some supplements may be harmful or interfere with conventional cancer treatment. We would advise all patients to talk to their oncologist if they are considering taking any supplements, and there’s more information on our website.
- Juicing: One version of the hoax email includes the claim that “Fresh vegetable juices provide live enzymes that are easily absorbed and reach down to cellular levels within 15 minutes to nourish and enhance growth of healthy cells.” This is utter nonsense on a biological level. Enzymes do not pass from the gut into the blood or tissues, and juicing to treat cancer or ‘remove toxins’ is nothing more than a diet fad. There’s no evidence that vegetable juices are any healthier than whole veg (in fact, juices have less fibre), and certainly no evidence that they can halt the growth of cancer.
This is unhelpful fear-mongering. Plastics that are marked as ‘microwaveable’ are safe to use in a microwave oven. Obviously anything that says it can’t be microwaved shouldn’t, including some plastics (such as margarine tubs) that will melt. If you are still worried about using plastic, or if it’s not clear whether a container is microwaveable, then don’t use it. Glass or china bowls work just as well. Just don’t use anything containing metal, or you will damage the oven.
On the opposite end of the temperature scale, freezing plastic containers or bottles doesn’t encourage chemicals to leach out of them – if anything, cooling them down will discourage any molecules from moving around. Johns Hopkins University have also published a statement on the hoax messages about freezing or microwaving plastics.
To sum up
Huge progress has been made in boosting long term cancer survival over recent decades. Today, half of all people diagnosed with cancer will survive for at least ten years, compared to a quarter back in the 1970s. But we need to do better.
While we can successfully treat many cancers, especially if they’re diagnosed early, thousands of people still lose their lives every year – including our own friends, family and colleagues here at Cancer Research UK.
Cancer is hundreds of different diseases, and each person’s cancer is as unique as they are. It’s a hugely complex problem, and there are no quick fixes. We don’t have all the answers yet, and that’s why we carry on researching better ways to prevent, diagnose and treat cancer.
These emails and other internet memes spread because they provide simple but misleading answers to complicated questions about cancer and science – things that are hard to explain and understand at the best of times, let alone when facing a cancer diagnosis. Nobody would be happier than us if lemons could cure cancer or if drinking enough kale juice could prevent it.