Plasma carotenoids as biomarkers of intake of fruits and vegetables: individual-level correlations in the European Prospective Investigation into Cancer and Nutrition (EPIC)

Objective: The aim in this study was to assess the association between individual plasma carotenoid levels (α-carotene, β-carotene, lycopene, β-cryptoxanthin, lutein, zeaxanthin) and fruit and vegetable intakes recorded by a calibrated food questionnaire (FQ) and 24-h dietary recall records (24HDR) in nine different European countries with diverse populations and widely varying intakes of plant foods.

Design: A stratified random subsample of 3089 men and women from nine countries participating in the European Prospective Investigation into Cancer and Nutrition (EPIC), who had provided blood samples and dietary and other lifestyle information between 1992 and 2000, were included.

Results: β-Cryptoxanthin was most strongly correlated with total fruits (FQ r=0.52, 24HDR r=0.39), lycopene with tomato and tomato products (FQ r=0.38, 24HDR r=0.25), and α-carotene with intake of root vegetables (r=0.39) and of total carrots (r=0.38) for FQ only. Based on diet measured by FQ and adjusting for possible confounding by body mass index (BMI), age, gender, smoking status, alcohol intake, and energy intake, the strongest predictors of individual plasma carotenoid levels were fruits (Rpartial2=17.2%) for β-cryptoxanthin, total carrots (Rpartial2=13.4%) and root vegetables (Rpartial2=13.3%) for α-carotene, and tomato products (Rpartial2=13.8%) for lycopene. For 24HDR, the highest Rpartial2 was for fruits in relation to β-cryptoxanthin (7.9%).

Conclusions: Intakes of specific fruits and vegetables as measured by food questionnaires are good predictors of certain individual plasma carotenoid levels in our multicentre European study. At individual subject levels, FQ measurements of fruits, root vegetables and carrots, and tomato products are, respectively, good predictors of β-cryptoxanthin, α-carotene, and lycopene in plasma.