There’s no scientific evidence to show that lemon juice can cure cancer, despite what the internet might tell you.

The UK charity Sense About Science will on Monday issue a new edition of their excellent booklet “I’ve got nothing to lose by trying it” as part of the Ask For Evidence campaign, which aims to empower patients and their families to ask for the scientific evidence behind claims made for treatments and products. We wrote this short piece for their website, looking at some of the “miracle cures” for cancer we’ve encountered. Sense About Science has gathered these stories together and will be sharing them on their website over the course of next week.

At Cancer Research UK, we’re often asked about alternative cancer cures. These are usually circulated on the internet and end up plastered onto our Facebook page (often accompanied by the phrase “they don’t want you to know about it). Just a small selection of the cures we’ve heard about recently includes lemon juice, baking soda, apricot kernels, coffee enemas, tropical fruit, “alkaline” foods (whatever they are…), even bleach. But while there are plenty of ‘miracle cures’ out there, a little investigation shows that there’s very little evidence that any of them actually work.

In some cases – particularly chemicals found in plants and other foodstuffs – there may be lab studies suggesting it has an anti-cancer effect. But many things can kill cancer cells growing in a Petri dish in the lab, and chemicals that seem promising in the lab or even in animal models of tumours can be disappointingly ineffective when faced with the real deal in a cancer patient.

Yet the internet is bursting with anecdotes from patients who have apparently been “cured” by all kinds of pills, lotions and potions. So what should we make of them?

Despite what people may claim, videos and stories are not scientific evidence for the effectiveness of any cancer treatment. When faced with a patient story, it’s impossible to tell whether these patients have been ‘cured’ by a particular treatment or not. We know nothing about their medical diagnosis (did they actually have cancer? If so, what type and how was it confirmed?), the stage and aggressiveness of the disease or their outlook.

Often it turns out that people have had conventional cancer treatments too, yet this may not be mentioned. We don’t know about the chemical composition of the treatment they got – for example, one alternative prostate cancer treatment was found to contain prescription drugs. And we only hear about the success stories – what about the people who have tried alternative therapies and not been cured? People who make bold claims only pick their best cases without presenting the full picture.

This highlights the importance of publishing data from rigorous lab research and well-designed clinical trials in peer-reviewed scientific and medical journals. Conducting proper clinical studies enables researchers to compare like with like, and prove that a prospective cancer treatment is safe and effective. And publishing their data in scientific journals allows doctors around the world to judge for themselves and use the information for the benefit of their patients.

This is the standard to which all conventional cancer treatments are held, and it’s one that alternative treatments should be held to too. Anecdotes and videos prove nothing and benefit no-one – we need reliable, scientific research to judge whether a treatment is effective.

When faced with a diagnosis of cancer, it’s tempting to turn to “Dr Google” to find out more, but we urge patients to check out the evidence behind any alternative treatments they might be thinking of taking and talk it through with a medical professional. Not only are people at risk of wasting their time and money on completely ineffective treatments, there is also the possibility that a therapy might be harmful or interact with conventional treatments.

Through our information services, we’re well aware how distressing this kind of misinformation about ‘cures’ for serious illnesses can be for people. It gives them false hope and can lower their confidence in the treatment they are receiving from their own doctors.

Cancer Research UK’s CancerHelp website provides a wealth of information on a range of alternative and complementary therapies, which is all supported behind-the-scenes by solid scientific research. We’ve also written here on the blog about conspiracy theories, alternative treatments and more.

Elsewhere, the American Cancer Society also has an impressive collection of evidence on alternative treatments, and the Memorial Sloan-Kettering Cancer Centre maintains a searchable database on herbs and supplements. Finally, Quackwatch has a list of some of the more unusual ‘miracle cures’ and a special message for patients seeking alternative treatments.

If you want to talk to someone about any cancer treatment, call the Cancer Research UK Information Nurses on freephone 0808 800 4040, 9am-5pm Monday-Friday.