Associations between long-term dietary fatty acid intake and risk of cardiovascular disease among Chinese adults: A nationwide, population-based, prospective cohort study

Background & Aims: Previous studies have established a significant association between dietary fatty acid intake and cardiovascular disease (CVD) risk; however, the long-term effects in China, where CVD rates are high, remain unclear. This study aims to assess the associations between long-term dietary fatty acid intake and CVD risk in Chinese populations. Methods: A total of 8,456 participants from the China Health and Nutrition Survey (CHNS) were enrolled. Dietary fatty acid intake was assessed using three-day 24-h dietary recalls combined with the dietary weighing method. CVD was defined as adults with myocardial infarction (MI) and/or stroke. Multivariable Cox proportional hazards models were used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs), while restricted cubic spline (RCS) curves assessed the non-linear association. Results: During a median follow-up of 7 years, 418 participants developed CVD (186 MI and 251 stroke cases, including 19 with both conditions). In Chinese adults, more polyunsaturated fatty acids (PUFA) and n-6 PUFA intake was associated with an increased risk of CVD. Specifically, higher linoleic acid (C18:2n-6) intake was associated with a higher risk of CVD (HR_Q4vsQ1=1.80, 95% CI: 1.32-2.45), MI (HR_Q4vsQ1= 1.68, 95% CI: 1.06-2.68), and stroke (HR_Q4vsQ1=1.78, 95% CI: 1.22-2.60). Similar associations were observed between α-linolenic acid (C18:3n-3) and CVD (HR_Q4vsQ1=1.88, 95% CI: 1.38-2.57) and MI risk (HR_Q4vsQ1=3.84, 95% CI: 2.17-6.78), but no significant association was found for stroke. Furthermore, higher saturated fatty acid (SFA) intake was associated with an increased MI risk (HR_Q4vsQ1=1.64, 95% CI: 1.03-2.65). In contrast, the intake of marine n-3 PUFA, mainly composed of eicosapentaenoic acid and docosahexaenoic acid, was inversely linked to MI risk (HR_Q4vsQ1=0.51, 95% CI: 0.33-0.80). No significant correlation was detected between dietary monounsaturated fatty acid and cardiovascular event risk in Chinese adults. Similar findings for these fatty acids were also observed in RCS analyses. Conclusion: Higher dietary intake of marine n-3 PUFA was associated with a lower MI risk, while intakes of n-6 PUFA, C18:2n-6, and SFA were linked to a higher CVD risk. These findings support limiting the intake of n-6 PUFA and SFA while increasing marine n-3 PUFA consumption in the Chinese population for CVD prevention, particularly MI.