Fruit and Vegetable Intake Assessed by Food Frequency Questionnaire and Plasma Carotenoids: A Validation Study in Adults

Abstract

Dietary validation studies of self-reported fruit and vegetable intake should ideally include measurement of plasma biomarkers of intake. The aim was to conduct a validation study of self-reported fruit and vegetable intakes in adults, using the Australian Eating Survey (AES) food frequency questionnaire (FFQ), against a range of plasma carotenoids. Dietary intakes were assessed using the semi-quantitative 120 item AES FFQ. Fasting plasma carotenoids (α- and β-carotene, lutein/zeaxanthin, lycopene and cryptoxanthin) were assessed using high performance liquid chromatography in a sample of 38 adult volunteers (66% female). Significant positive correlations were found between FFQ and plasma carotenoids for α-carotene, β-carotene and lutein/zeaxanthin (52%, 47%, 26%, p < 0.001, 0.003, 0.041; respectively) and relationships between plasma carotenoids (except lycopene) and weight status metrics (BMI, waist circumference, fat mass) were negative and highly significant. The results of the current study demonstrate that carotenoid intakes as assessed by the AES FFQ are significantly related to plasma concentrations of α-carotene, β-carotene and lutein/zeaxanthin, the carotenoids commonly found in fruit and vegetables. Lower levels of all plasma carotenoids, except lycopene, were found in individuals with higher BMI. We conclude that the AES can be used to measure fruit and vegetable intakes with confidence.

Carotenoids and alkylresorcinols as objective biomarkers of diet quality when assessing the validity of a web-based food record tool and a food frequency questionnaire in a middle-aged population

“…green leafy vegetables, tomatoes, green beans, peppers, green peas, corn, avocado, broccoli, mushrooms, cabbage, cucumber, leek, olives, aubergine, squash, asparagus, cauliflower and carrots); F + B, fruits and berries (both fresh and frozen); J, juice *significant at P < 0.05 **significant at P < 0.01 Table 4 Spearman's correlation between energy-adjusted intake of whole grain wheat and rye (g/MJ) and plasma alkylresorcinol homologues for women and men separately Abbreviations: AR alkylresorcinol homologues *significant at P < 0.05 **significant at P < 0.01 displayed poor results with lycopene as an indicator of fruit and vegetable intake [40][41][42][43]. This might be due to large individual variations in absorption, metabolism and excretion of lycopene [44,45].…”

Comparison of fruit and vegetable intakes during weight loss in males and females

“…17,18 The Australian Eating Survey uses a standard portion size derived from the 1995 National Nutrition Survey or a 'natural' serving size (for example, a piece of fruit). Twenty-one questions related directly to the intake of vegetables and 11 questions related to fruit intake.…”

Analysis of energy metabolism in humans: A review of methodologies

“…While the complexity of metabolomics analyses makes it unlikely to replace more cost-effective dietary assessment tools, a more common use of biomarkers is to validate self-reported measures. For example, an increase in plasma carotenoids levels has often been used to validate high fruit and vegetables intake reported in FFQs and food diaries [120], [121]. Prentice and colleagues [122] demonstrated the use of biomarkers from sub-groups within study cohorts to develop algorithms to calibrate self-reported dietary measures as an alternative for more objective measures at an acceptable cost.…”