The Gap Between Perceived and Objective Diet Quality in Patients with Lynch Syndrome

Background and Aims: Lynch syndrome (LS) confers a substantially elevated lifetime risk of colorectal cancer (CRC). While enhanced endoscopic surveillance and aspirin chemoprevention are the cornerstones of management, evidence suggests modifiable lifestyle factors like diet may help mitigate or modify hereditary cancer risk. Because specific LS dietary guidelines are lacking, general CRC prevention recommendations are often substituted. Therefore, the aim of this study was to conduct a detailed and comprehensive examination of dietary habits, cancer-related dietary beliefs, and overall cancer-related worry in individuals with Lynch syndrome who attend a Gastrointestinal (GI) Risk Management Clinic.

Methods

A cross-sectional study was conducted using data collected between June 2025 and June 2026 from individuals with a confirmed LS diagnosis attending a tertiary Gastrointestinal Risk Management Clinic in Melbourne, Australia. Participants completed electronic questionnaires capturing demographics, clinical history, a Food Frequency Questionnaire, the 14-item Mediterranean Diet Adherence Screener (MEDAS), and the Cancer Worry Scale (CWS). Self-reported dietary beliefs regarding the relationship between food and cancer risk were captured. Lifestyle behaviors were benchmarked against the Australian Bowel Cancer Risk Reduction Recommendations. The MEDAS was primarily analysed as a population-specific top-vs-bottom half (“better adherence”), and secondarily as a priori “good” adherence (MEDAS > 7).