New research from World Cancer Research Fund (WCRF) has revealed that 44% of patient-facing NHS staff encounter inaccurate or misleading nutrition or supplement information from patients at least once a week, with 6% facing this daily or almost daily.
The findings, published to coincide with Cancer Prevention Action Week (15-21 June 2026), paint a picture of growing pressure on healthcare professionals as online health misinformation becomes increasingly widespread.
The scale of the problem
The charity’s survey of 1,043 NHS workers found that 40% of healthcare professionals are not confident that nutritional advice they encounter online is correct, while 37% say they are uncertain about where to find reliable, evidence-based information on supplements. Despite this, healthcare professionals remain the most trusted source of nutrition advice for the general public.
A separate YouGov poll of 2,125 UK adults highlights a troubling confidence gap. While 62% of UK adults say they feel confident finding trustworthy nutrition information online, this rises to 72% among those whose primary news source is social media. However, that same group is also more likely to hold inaccurate beliefs about cancer prevention. Compared with those who do not primarily rely on social media for news, they are less likely to identify eating plenty of fibre as something that can reduce cancer risk (48% vs 55%), more likely to believe certain supplements can reduce cancer risk (15% vs 11%), and more likely to think certain foods or diets can “starve” cancer (13% vs 7%).
The poll also found that one in five UK adults (20%) believe detoxes or cleanses are good for health, 11% of 18 to 34-year-olds wrongly think eating the same superfood most days can reduce cancer risk, and more than one in five (21%) spend over £10 a month on dietary supplements.
WCRF warns this matters because around four in ten cancer cases in the UK are preventable, and misleading information can divert people away from the everyday habits known to reduce cancer risk.
Gaps in healthcare training
The issue is compounded by longstanding gaps in nutrition training for medical professionals. Previous UK research found that more than 70% of medical students and doctors surveyed reported receiving fewer than two hours of nutrition training at medical school.
WCRF is already working with medical schools at the Universities of Lincoln and Southampton to develop practical teaching resources on diet, weight and cancer risk, and has a pilot scheme with NHS Greater Glasgow and Clyde that integrates its Cancer and Nutrition Helpline into patient care pathways.
The TRUST Test
In response to the findings, WCRF has launched a new tool called the TRUST Test, designed to help both the public and healthcare professionals identify health misinformation online. The framework draws on misinformation detection indicators tested and validated by researchers at University College London (UCL).
The five steps are:
T – Too good to be true? Does it promise unrealistic results or quick fixes?
R – Research-backed? Does it trace back to scientific evidence rather than personal stories or opinions?
U – Understood? Has the person sharing the information understood the dangers and risks, or have they downplayed harms and promoted unproven remedies over appropriate medical care?
S – Source quality? Does it come from a trusted organisation or scientific source, and what do other experts say?
T – Think before you share. If it does not pass the TRUST Test, do not pass it on.
The TRUST Test is now live at wcrf.org/trust-test.
Calls for action
WCRF is calling on the UK Government to use the NHS Workforce Plan to strengthen support for evidence-based advice on cancer prevention, nutrition and physical activity. The charity stresses this is not about expecting healthcare staff to act as dietitians, but to equip them with clear, trusted information so they can respond confidently when patients raise questions about claims they have seen online.
WCRF UK Director Steven Greenberg said: “Misinformation about diet and cancer is not just confusing, it is putting people’s health at risk. The danger is not just false claims, it is advice that is distorted, taken out of context, or presented in a way that hides the risks. We know people are acting on this information, particularly when it comes from social media, and that can have real consequences for their health.”
Alex Ruani, Doctoral Researcher in health-diet misinformation at UCL, who has been advising WCRF on the campaign, said: “We now have strong evidence that nutrition misinformation is not just misleading – it can be actively harmful. UCL research shows that inaccurate or incomplete health advice can influence real-world decisions, from dangerous dieting and supplement misuse to delaying or abandoning effective treatment.”
WCRF cancer prevention recommendations
WCRF recommends the following steps to reduce the risk of developing cancer: maintaining a healthy weight, being physically active, eating wholegrains, vegetables, fruit and beans, limiting fast foods, red and processed meat, sugar-sweetened drinks and alcohol, not using supplements for cancer prevention, and breastfeeding where possible. Not smoking and staying safe in the sun are also important risk reduction measures.
Further information on the Science Not Fiction campaign and the TRUST Test is available at wcrf.org.
