Association of dietary choline and betaine intake with all-cause mortality: a longitudinal study from the China Health and Nutrition Survey.

Epidemiologic evidence on the association between dietary choline, betaine and mortality risk remains limited, particularly among non-Western populations. We examined the association of dietary choline and betaine with all-cause mortality in Chinese adults using data from the China Health and Nutrition Survey 1991-2015. We included 9027 men and 8828 women without CVD and cancer at baseline. Dietary intake was assessed using 3-day 24-hour dietary recalls and household food inventories. Death was ascertained through household surveys in each wave. Time-dependent Cox proportional hazards regression models estimated multivariable-adjusted hazard ratios (HRs) and 95 % CIs. During a median follow-up of 9·1 years, 891 men and 687 women were deceased. Higher total choline intake was associated with lower all-cause mortality in both men (HR_{Q5 v. Q1} = 0·58 (95 % CI: 0·45, 0·74)) and women (HR_{Q5 v. Q1} = 0·59 (95 % CI: 0·44, 0·78)). The dose-response curve were reverse J-shaped in men and L-shaped in women (both P-nonlinear ≤ 0·005). Similarly, fat-soluble choline intake was inversely associated with mortality in both men (HR_{Q5 v. Q1} = 0·59 (95 % CI: 0·46, 0·75)) and women (HR_{Q5 v. Q1} = 0·53 (95 % CI: 0·40, 0·70)), showing reverse J-shaped patterns (both P-nonlinear < 0·001). A J-shaped association between water-soluble choline and mortality was observed in women (P-nonlinear < 0·001), but a null association was found in men. Betaine intake was not associated with all-cause mortality in either sex. Our findings suggest that adequate choline intake is linked to reduced all-cause mortality in Chinese adults with predominantly plant-based diets.