# Ask about diet at diagnosis, and prebunk the myths before the internet does

Source: https://onco.cc/ideas/idea-nl-ask-about-diet-prebunking/  
OnCo record `idea-nl-ask-about-diet-prebunking` (Idea). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Almost every newly diagnosed patient searches for what to eat and finds sugar-starvation, alkaline and juice-cure claims. If the oncology team asks about diet first and hands over good information, the myths have less room.

## Summary

Patients report that clinicians rarely discuss diet, so they turn to social media and supplement marketing, where unproven claims dominate. Prebunking, warning people about a specific manipulation before they encounter it, has randomised evidence from misinformation research and from HPV vaccination. A short, structured diet and supplement conversation at the first oncology visit, with a dietitian-authored handout that names and explains the common myths and offers what is actually supported (fibre, protein, activity, alcohol, smoking), could be tested cheaply.

## Fields

- Kind: Idea
- Last checked: 2026-09-08
- Hypothesis: A five-minute structured diet conversation plus prebunking materials at the first oncology consultation reduces adoption of unproven diets and antioxidant supplements at three months by half and increases dietitian referral uptake, without increasing anxiety.
- Rationale: Misinformation fills a vacuum; the evidence that patients want diet advice and do not get it is consistent; prebunking is cheap and has experimental support. Dietitian referral is the constructive alternative.
- Proposed test: Cluster-randomised trial across oncology clinics with patient-reported diet and supplement behaviours at 3 and 6 months, belief in specific myths, anxiety and dietitian referral rates as endpoints.
- Maturity: speculative
- Actor: clinic

## Sources

- Bottleneck evidence (Misinformation and unproven therapies): Johnson et al., Cancer misinformation and harmful information on Facebook and other social media (JNCI 2022): https://doi.org/10.1093/jnci/djab141

## Connected records

- ideas: [A cancer misinformation rapid-response unit that rebuts within 48 hours](https://onco.cc/ideas/idea-moon-misinformation-rapid-response/), [Inoculate newly diagnosed patients against common cancer scams](https://onco.cc/ideas/idea-moon-prebunking-at-diagnosis/)
- fronts: [Diet, Exercise & Lifestyle](https://onco.cc/fronts/nutrition-lifestyle/), [Supportive Care & Survivorship](https://onco.cc/fronts/supportive-care/)
- technologies: [Dietary supplements during cancer treatment: interactions and harms](https://onco.cc/technologies/dietary-supplements-treatment-interactions/), [Ketogenic diets in glioblastoma](https://onco.cc/technologies/ketogenic-diet-glioblastoma/), [Oncology nutrition assessment and medical nutrition therapy](https://onco.cc/technologies/nutrition-screening-mnt/)
- terms: [Unproven diet claims (alkaline, juice, 'anti-cancer' diets)](https://onco.cc/terms/unproven-diet-claims/), [Warburg-effect diet claims ('sugar feeds cancer')](https://onco.cc/terms/warburg-effect-diet-claims/)
- bottlenecks: [Knowledge reaches practice too slowly](https://onco.cc/bottlenecks/b-knowledge-diffusion/), [Misinformation and unproven therapies](https://onco.cc/bottlenecks/b-misinformation/), [Patients lack understanding, navigation and agency](https://onco.cc/bottlenecks/b-patient-voice/)
- key papers: [Cancer Misinformation and Harmful Information on Facebook and Other Social Media: A Brief Report](https://onco.cc/key-papers/paper-johnson-j-natl-cancer-inst/)

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