Dispelling misinformation about dietary supplements has become a routine task for NHS clinicians, according to new polling that points to a growing and largely unacknowledged pressure on frontline healthcare. What was once an occasional conversation is now, for many staff, a weekly occurrence.

The survey, commissioned by the World Cancer Research Fund and conducted by YouGov among 795 NHS workers, found that two in five frontline staff encounter patients raising inaccurate or misleading information about supplements at least once a week. This percentage increases to 53% among nurses and midwives. The time taken to address these claims is time that cannot be spent elsewhere, and clinicians are noticing.

The supplements most frequently at the centre of false claims include turmeric, St John's wort and magnesium. Online, these are often promoted as safe because they are sold without prescription or labelled as natural. Clinically, the picture is more complicated. Liver injury may be caused by an intake of turmeric supplements. St John's wort is known to interact with a range of prescribed medications. Magnesium, widely taken for sleep, exists in multiple forms with different effects, some of which cause gastrointestinal problems. Dr Philippa Kaye, a GP, noted that patients frequently assume over-the-counter products carry no risk. "If something works, then there is an active ingredient in it that may also cause problems," she said.

The results of the survey, which was commissioned by the WCRF in advance of Cancer Prevention Action Week, have prompted the organization to focus its advocacy efforts over the next three years on the dangers of health misinformation.  Its UK director, Steven Greenberg, said social media carries false claims about cancer prevention and cures ranging from horse wormers to apricot kernels, which can cause serious cyanide toxicity, to more commonplace substances such as vitamin C and sugar. The concern is not only that patients are acting on bad information, but that they are being pulled away from dietary and lifestyle changes with a genuine evidence base behind them.

Sharron Moffatt was diagnosed with breast cancer in 2024 and shared her diagnosis publicly. The response she received illustrated what clinicians are now dealing with at scale. "Almost overnight people were recommending everything from special waters and supplements to products claiming to boost recovery or even cure cancer," she said. Many of those recommendations came from people who had seen persuasive claims online and passed them on with good intentions. When Moffatt sought evidence for what was being suggested, she rarely found any. When she pressed further, she was met with hostility or no answer at all. Her conclusion was direct: when fear is driving decisions, the promise of a miracle cure is hard to resist.

The survey also found that many NHS staff feel ill-equipped to counter entrenched beliefs in unproven therapies. Specific examples included patients who believe eating superfoods daily or following a dietary detox reduces cancer risk. Rachel White, an oncology dietitian, described misinformation as a challenging part of her role. "Patients are making changes to try to improve their health and survival, but what they often do not realise is the danger or harm they can be doing instead," she said. The WCRF is urging the government to use the forthcoming NHS long-term workforce plan for England to provide staff with training and access to reliable resources to address what it calls an emerging crisis.

The government's position is that patients should consult qualified health professionals rather than relying on social media, and that platforms should act quickly to remove misleading health content. "Your health is too important to leave to social media and the internet," a spokesperson said.

That message is sensible, but it places the burden on individuals already being failed by the information environment around them. For the NHS, the problem is structural. Clinical time spent correcting false supplement claims is clinical time lost. As the volume of health misinformation online grows, so does the cost of managing its consequences inside a system with little capacity to absorb it.