Patients aged >40 years who underwent elective colonoscopies were recruited from ten institutions. Patients with a history of colorectal cancer or long-term dietary interventions were excluded. Participants completed a food frequency questionnaire (FFQ) prior to endoscopy. FFQ data were analyzed using energy-, age-, sex-, and body mass index-adjusted models; the dietary supplemental omega-3 intake was analyzed separately. Colonoscopy outcome data, including the adenoma number, pathology, and location, were collected. Participants were stratified into omega-3 consumption quartiles to assess colorectal adenoma incidence trends using P for trend analysis.

Inclusion Criteria:

• all patients aged more than 40 years of age, scheduled for elective colonoscopy.

Exclusion Criteria:

• inflammatory bowel diseases
• history of colorectal neoplasms
• prior gastrointestinal surgery
• substance abuse including alcohol
• an inability to complete the survey due to emergency endoscopy
• cognitive impairments and those undergoing significant dietary modifications

Multi-center, nationwide cohort in Korea