"People are often told that certain foods, supplements or restrictive diets can prevent cancer, treat cancer or 'starve' cancer, but these claims are rarely that simple and can be misleading."
- Rachel White - Perci Health
New data from Perci Health has revealed that most working-age adults are failing to follow evidence-based cancer prevention guidelines, and that misinformation is driving poor decisions for people living with cancer.
The World Cancer Research Fund (WCRF) is marking Cancer Prevention Action week 2026, which runs from 15th to 21st June, by launching the campaign ‘Science Not Fiction.’ This follows research showing that 44% of patient-facing NHS staff are asked about inaccurate or misleading nutrition or supplement claims at least once a week.
WCRF warns that misleading advice is distracting people from the lifestyle behaviours most strongly linked to reduced cancer risk, and that around four in ten UK cancer cases are preventable through lifestyle changes.
Perci Health’s digital cancer risk assessment, completed by members and covering the key lifestyle factors known to affect cancer risk, reveals that most working-age adults are significantly under-adherent to evidence-based prevention guidelines.
81% show low adherence to nutritional recommendations linked to reduced cancer risk, 63% have a BMI associated with elevated cancer risk, and 63% show low adherence to other lifestyle guidelines, including sun protection behaviours.
However, Perci Health says these figures do not reflect a lack of concern about cancer, but instead reflect a population being pulled in the wrong direction by misinformation, conflicting advice and the volume of unregulated health content circulating online.
This is reinforced by Perci Health's Generation Risk report, which surveyed 2,000 working-age adults across the UK. It found that only 24% of under-35s recognised diet as a cancer risk factor, and that men aged 25 to 34 were the most likely of any group to believe no lifestyle factors are related to cancer risk at all, despite belonging to the age group seeing the fastest rise in cancer incidence globally.
Perci Health also underlines that prevention failures do not stay in the pre-diagnosis phase. For people already living with or beyond cancer, the same pattern continues, often with more serious consequences.
Perci Health's clinical service data shows that dietitians are its second most accessed service after psychologists, accounting for 28% of all appointments. Questions around nutritional myths, supplements, restrictive diets and what to eat during or after cancer treatment are among the most common reasons people seek support, with misinformation or myth-debunking covered in 92% of all nutrition consultations.
As part of the campaign, WCRF has launched its TRUST Test, encouraging people to question health claims by considering whether advice is transparent, realistic, evidence-based, supported by qualified experts and safe to follow.
Perci Health says tools such as the TRUST Test are important because they give people a simple framework for evaluating health information before acting on it or sharing it. However, the company says people also need access to qualified cancer experts who can help them understand what information is relevant to their own risk, diagnosis, treatment or long-term health needs.
READ MORE: Aviva calls for earlier action as £38m paid in prostate cancer claims
"WCRF’s TRUST Test is a really helpful reminder that people need simple ways to question the health information they see online," Kelly McCabe, co-founder and CEO of Perci Health and former oncology dietitian, said. "But we also need to recognise that cancer is an area where people can feel frightened, overwhelmed or desperate for answers.
"As a former oncology dietitian, I know how difficult it can be for people to separate evidence-based nutrition advice from claims that sound convincing but are not clinically appropriate. This becomes even more challenging in cancer, where people are often looking for reassurance, control and practical steps they can take.
"Nutrition and supplements are a particularly difficult area because so much of the content people see online sounds credible, personal or hopeful. But when that information is inaccurate, exaggerated or not based on evidence, it can distract people from the actions that are proven to make a difference.
"Workplaces have a real opportunity to provide trusted, evidence-based cancer education in a way that feels accessible, relevant and engaging. This is not about placing responsibility on employees. It is about giving people better access to credible information and specialist support."
Rachel White, specialist cancer dietitian at Perci Health, added: "Cancer nutrition is one of the areas where misinformation can spread very quickly, particularly online. People are often told that certain foods, supplements or restrictive diets can prevent cancer, treat cancer or 'starve' cancer, but these claims are rarely that simple and can be misleading.
"Good nutrition advice should help people feel informed and supported, not blamed or overwhelmed. For cancer prevention, we need to focus on the evidence around sustainable lifestyle factors such as eating a balanced diet, including fibre-rich foods, maintaining a healthy weight, reducing alcohol and being physically active.
"For people living with or beyond cancer, the advice may be very different depending on their diagnosis, treatment, symptoms and wider health needs. That is why access to specialist cancer nutrition support matters. It helps people understand what is relevant to them, what is backed by evidence and what they should be cautious about."
Perci Health is calling on employers, insurers and employee benefits providers to use Cancer Prevention Action Week as a prompt to review whether their workforce health strategies are doing enough.
This includes moving beyond generic wellbeing content to provide evidence-based cancer prevention education that addresses the lifestyle factors with the strongest links to reduced risk and actively counters common myths, access to individual cancer risk assessment tools that show employees their personal risk picture and what to do about it, and clear guidance on screening, including for employees not yet eligible for NHS programmes.
Access to specialist cancer clinicians, including dietitians, cancer nurse specialists and psychologists, for employees affected by cancer or concerned about their risk, as well as full-pathway support spanning prevention, treatment and recovering health, are also recommended by the company.
"Employees are already searching for answers about cancer risk, nutrition, screening and symptoms," Kelly McCabe added. "The problem is that too many of them are finding those answers in the wrong places.
"The employers who give their people access to trusted, specialist-led cancer support, across the full journey from prevention to recovering health, will see the difference in their people's lives, and in their absence and claims data."
