Night shift work, dietary patterns, and coronary heart disease

Shift workers exhibit a higher incidence of coronary heart disease (CHD) than daytime workers. We examined whether this difference in CHD incidence between shift workers and daytime workers is associated with two dietary factors linked to lower CHD risk-daily fiber intake and meat avoidance-using UK Biobank data. The study included 222,801 participants (53.8% women; mean age 52.6 years), categorized as daytime workers, shift workers with no or occasional night shifts, or regular night shift workers. Dietary habits were assessed via touchscreen dietary questionnaires. During a median follow-up of 12.6 years, 12,265 fatal and non-fatal CHD events occurred. Compared with daytime workers, regular night shift work-but not shift work with no or occasional night shifts-was associated with higher CHD incidence (hazard ratio [HR] 1.10, 95% CI 1.01-1.20). HRs for CHD were higher (vs. daytime work) in both shift work groups among participants with lower daily fiber intake, whereas they were attenuated among those with higher fiber intake (p < 0.05 for interaction). Meat avoidance was associated with a 10.4% lower CHD HR compared with meat consumption (p = 0.020), although no significant interaction with work schedule was observed. In summary, while our finding that meat avoidance is associated with modestly lower CHD HR across work schedules aligns with established cardiovascular recommendations, our observation that higher fiber intake may reduce CHD differences specifically linked to night shift work highlights an additional, shift-specific dietary consideration that could complement the American Heart Association's Life's Essential 8.