Earlier this week, a small furore broke out after TV personality Noel Edmonds made some online claims about an unproven cancer treatment, and about whether cancer can be ‘caused by stress and negativity’.

So we want to clarify what the current scientific evidence says about the link between negativity, stress and cancer, and about electromagnetism – the basis of the treatment that made the headlines this week.

Does negativity or stress cause cancer?

Links between negative thinking, stress and cancer is a topic that regularly comes up in the media and on social media. But there is no good evidence that negative thoughts or stress itself can raise a person’s risk of cancer).

The large studies to date recording people’s stress levels and their likelihood of cancer have concluded that being stressed doesn’t mean you are more likely to develop the disease – and it’s something we’ve discussed in detail on this blog too.

But it’s a complex issue. There are many factors that can affect cancer risk, and it is very difficult to study any of these in isolation, so this kind of research (called population research, or epidemiology) can be difficult for scientists to interpret. Even when an increased risk of cancer in people who perceive themselves to be stressed is recorded in a study, it doesn’t necessarily mean that stress itself is the underlying reason.

For example being stressed can affect whether people do things like smoke or drink alcohol, and how much and what they eat – all of which do affect cancer risk.

But it bears repeating – the best studies looking at this topic have failed to show a link between emotional stress and an increased risk of cancer.

Electromagnetic therapy – what is it?

So what about therapies using electromagnetic fields? The concept of using electromagnetic therapy to treat cancer is not new idea. Back in the 1920s, an American scientist called Royal Raymond Rife built the first known device that tried to use electromagnetic pulses to try and kill cancer cells, known as a Rife machine.

But in all the years since, no reliable evidence has ever been produced that Rife machines – or any similar devices producing low-frequency electromagnetic pulses – have any benefit for cancer patients. Nor have organisations that scrutinise new treatments and devices (like the US Food and Drug Authority or the European Medicines Agency) approved any as a therapy for any type of disease.

And as often the case with alternative therapies, there are potential harms – people have reported electric shocks and rashes from some devices, and there’s always the risk that people will try unproven therapies instead of treatments that are proven to work.

Our bodies use tiny electrical currents to function, for example our heart uses electrical currents to beat. There’s no telling what the possible long term harms of using electromagnetic therapy might be, particularly for people whose bodies are coping with other cancer treatments like chemotherapy.

And it can be extremely dangerous buying unknown, untested devices online.

That’s not to say that other forms of electromagnetism don’t play a role in cancer treatment – they most certainly do. High-frequency electromagnetism underpins imaging equipment, like X-rays, CT and MRI scans.

And of course radiotherapy – a cornerstone of treatment – consists of high-energy electromagnetic waves that destroy tumours.

But this is very different from the low-frequency waves produced by the devices that hit the headlines this week.

Is it all unfounded?

Nothing is set in stone. All we can base this information on is the evidence we have to date. Science is making constant progress, so we don’t know whether electromagnetic therapy will one day be a part of treatment for some cancer patients or not.

In fact, there is rigorous scientific research being carried out into low-frequency electromagnetic radiation (for example here). But this research is still at the earliest stage, using cancer cells growing in the lab, so there’s no evidence yet that it will work effectively in people.

So despite various claims you may have read in the papers over the last few days, there’s no good evidence that stress causes cancer, nor that machines producing low-frequency electromagnetic pulses can help kill cancer cells in patients with the disease.