Is Plasma Plant Sterols a Biomarker of Plant Sterols Intake Estimated from FFQ and Multiple Dietary Recalls?

Background Plant sterols have many health benefits including reduce risk of heart diseases and prevent cancers. We have previously found that plasma plant sterols are higher in vegans than non vegetarians. It is not clear, howeer, if plant sterols in plasma reflect dietary intake. Objective We compared plasma plant sterol levels with plant sterol intake estimated from food frequency questionnaire (FFQ) and 24‐hours dietary recalls (24‐HR) of the Adventist Health Study ‐2 cohort. Design Plasma sitosterol and campesterol were measured by gas‐liquid chromatography. Intake of β‐sitosterol and campesterol was estimated from FFQ and six 24‐HR. The plant sterols content of foods were derived primarily from USDA SR 27 and also from available literature between years 1999–2011. Results Mean (SD) age of the analytic cohort was 60 (14) years, and included 34% men, and 54% non‐Blacks. Mean (SD) was 4.2 (2.3) μg/ML for plasma campesterol and 3.3 (1.6) μg/ML for plasma sitosterol. In FFQ, mean (SD) intake of campesterol and β‐sitosterol in mg/d was 38.03 (22.06) and 170.57 (95.72), respectively. Mean (SD) intake of campesterol and β‐sitosterol from 24‐HR were 22.80 (13.82) mg/d and 91.70 (50.09) mg/d, respectively. Correlations between plasma concentration and 24‐HR for campesterol and sitosterol were not significant. The correlation between 24‐HR and FFQ was 0.16 (p <.0001) for campesterol and 0.24 (p <.0001) for sitosterol. Conclusion Plasma concentration of plant sterols does not appear to be a biomarker of phytosterols intake. Although weak, correlations between plant sterols intake in FFQ and 24‐HR may be improved with adjustment for measurement errors or by food group assessment. Support or Funding Information This project was funded by Unilever. Collection of blood and dietary recalls was funded by the National Cancer Institute.