Intake of phytosterols from natural sources and risk of cardiovascular disease in the European Prospective Investigation into Cancer and Nutrition-the Netherlands (EPIC-NL) population

BACKGROUND: Phytosterols (PSs) are known to lower low-density lipoprotein cholesterol (LDL-C), an established risk factor for cardiovascular disease (CVD). Whether a high intake of PS reduces CVD risk is unknown. This observational study aimed to investigate the associations between intake of naturally occurring PSs, blood lipids and CVD risk.

METHODS: The study included 35,597 Dutch men and women, participating in the European Prospective Investigation into Cancer and Nutrition-the Netherlands (EPIC-NL) study. At baseline, intakes of naturally occurring PSs were estimated with a validated food frequency questionnaire and non-fasting blood lipids were measured. Occurrence of CVD, coronary heart disease (CHD) and myocardial infarction (MI) was determined through linkage with registries.

RESULTS: The average energy-adjusted PS intake at baseline was 296 mg/d (range: 83-966 mg/d). During 12.2 years of follow-up, 3047 CVD cases (8.6%) were documented. After adjustment for confounders, PS intake was not associated with risk of CVD, CHD or MI (p-value trend > 0.05); hazard ratios ranged from 0.90-0.99 for CVD, from 0.83-0.90 for CHD and from 0.80-0.95 for MI risk across quintiles of PS intake and were almost all non-significant. Higher PS intake was associated with lower total cholesterol (-0.06 mmol/l per 50 mg/d; p-value = 0.038) and lower LDL-C (-0.07 mmol/l; p-value = 0.007), particularly among men. In mediation analysis, LDL-C did not materially affect the association between PS intake and CVD risk.

CONCLUSIONS: In this population with a relatively narrow range of low naturally occurring PS intakes, intake of PS was not associated with reduced CVD risk despite lower LDL-C concentrations in men.