Dietary biomarker evaluation in a controlled feeding study in women from the Women’s Health Initiative cohort ,

Abstract

Background: Controlled human feeding studies are necessary for robust nutritional biomarker development and validation. Previous feeding studies have typically evaluated single nutrients and tested relatively few diets. Objectives: The objectives were 1) to simultaneously associate dietary intake with a range of potential nutritional biomarkers in postmenopausal women by using a controlled feeding study whereby each participant was provided a diet similar to her usual diet and 2) to evaluate serum concentrations of select nutrients as potential biomarkers with the use of established urinary recovery biomarkers of energy and protein as benchmarks for evaluation. Design: Postmenopausal women from the Women's Health Initiative (n = 153) were provided with a 2-wk controlled diet in which each individual's menu approximated her habitual food intake as estimated from her 4-d food record and adjusted for estimated energy requirements. Serum biomarkers, including carotenoids, tocopherols, folate, vitamin B-12, and phospholipid fatty acids, were collected at the beginning and end of the feeding period. Doubly labeled water and urinary nitrogen biomarkers were used to derive estimates of energy and protein consumption, respectively. Results: Linear regression of (ln-transformed) consumed nutrients on (ln-transformed) potential biomarkers and participant characteristics led to the following regression (R 2 ) values for serum concentration biomarkers: folate, 0.49; vitamin B-12, 0.51; a-carotene, 0.53; b-carotene, 0.39; lutein + zeaxanthin, 0.46; lycopene, 0.32; and a-tocopherol, 0.47. R 2 values for percentage of energy from polyunsaturated fatty acids and urinary recovery biomarkers of energy and protein intakes were 0.27, 0.53, and 0.43, respectively. Phospholipid saturated fatty acids and monounsaturated fatty acids and serum g-tocopherol were weakly associated with intake (R 2 , 0.25). Conclusions: Serum concentration biomarkers of several vitamins and carotenoids performed similarly to established energy and protein urinary recovery biomarkers in representing nutrient intake variation in a feeding study, and thus are likely suitable for application in this population of postmenopausal women. Further work is needed to identify objective measures of categories of fatty acid intake. This trial was registered at clinicaltrials.gov as NCT00000611.Am J Clin Nutr 2017;105:466-75.

STRATOS guidance document on measurement error and misclassification of variables in observational epidemiology: Part 1—Basic theory and simple methods of adjustment

“…However, they are the best method currently available . Prentice and others, using data from a unique large feeding study, are currently engaged in expanding the list of dietary components for which unbiased measurements are available.…”

Metabolomics‐Based Dietary Biomarkers in Nutritional Epidemiology—Current Status and Future Opportunities

“…A recent paper by Lampe and colleagues illustrated the potential of candidate biomarkers for dietary assessment in terms of nutrient intake . The work demonstrated that a series of dietary biomarkers including carotenoids, tocopherols, folate, and vitamin B12 performed as well as established energy (doubly labeled water) and protein biomarkers (urinary nitrogen) in representing nutrient intake.…”

Research Strategies for Nutritional and Physical Activity Epidemiology and Cancer Prevention

“…Human feeding studies provide an important context for intake biomarker development and validation. A recent report describes a novel feeding study design in which participants were provided a diet approximating their usual diet for a two week period, with various blood and urine measures for intake variations among study participants, resulting in identification of suitable biomarkers for several nutritional variables (17). Specimens from this study are currently undergoing extensive metabolomic profiling to identify additional intake biomarkers.…”

“…There are a few established urine-based intake biomarkers, including a doubly labeled water biomarker of total energy intake, a urinary nitrogen biomarker of protein intake, and 24-hour excretion-based biomarkers of sodium and potassium. Blood-based biomarkers of several micronutrients have also shown promise in human feeding study evaluation (17). Once established, the objective intake measures can be used to correct self-report assessments for measurement error.…”