Biomarkers of Whole-Grain and Cereal-Fiber Intake in Human Studies: A Systematic Review of the Available Evidence and Perspectives

Abstract

High whole-grain consumption is related to better health outcomes. The specific physiological effect of these compounds is still unrevealed, partly because the accurate estimation of the intake of whole grains from dietary assessments is difficult and prone to bias, due to the complexity of the estimation of the intake by the consumer. A biomarker of whole-grain intake and type of whole-grain intake would be useful for quantifying the exposure to whole-grain intake. In this review, we aim to review the evidence on the potential biomarkers for whole-grain intake in the literature. We conducted a systematic search in Medline, Embase, Web of Science, and the Cochrane database. In total, 39 papers met the inclusion criteria following the PRISMA guidelines and were included. The relative validity, responsiveness, and reproducibility of these markers were assessed for short-, medium-, and long-term exposure as important criteria for the potential use of these biomarkers from a clinical and research perspective. We found three major groups of biomarkers: (1) alkylresorcinol, as well as its homologs and metabolites, assessed in plasma, adipose tissue biopsies, erythrocyte membranes, and urine; (2) avenacosides, assessed in urine samples; and (3) benzoxazinoid-derived phenylacetamide sulfates, assessed in blood and urine samples. The reviewed biomarkers may be used for improved assessment of associations between whole-grain intake and health outcomes.

Foods as First Defense Against COVID-19

“…Many of these dietary components contribute in wide-ranging physiological functions in the body [44]. The consumption of whole grain in higher proportion results in better health outcomes [45] in present COVID-19 pandemic crises. Intake of whole grains should be preferred because grains with minimal processing maintain their nutritive values, while refining of grains results in reduction of dietary fibers and numerous bioactive compounds.…”

The Effect of Rye-Based Foods on Postprandial Plasma Insulin Concentration: The Rye Factor

“…Lignans and alkylresorcinols have been shown in in vitro and animal studies to improve insulin sensitivity ( 64 , 65 ). An association between alkylresorcinols and insulin sensitivity has been confirmed in human studies ( 29 , 66 ), but since alkylresorcinols may just be a marker of whole grain rye and wheat intake, it is difficult to distinguish between the effect of the alkylresorcinols and other components of whole grain products that could influence insulin sensitivity ( 67 ). Human studies on lignans and health has primarily been focused on cancer, due to the potential mild estrogenic effects of certain lignan metabolites ( 68 ).…”

Evaluating an Intervention to Increase Cereal Fiber Intake in Children: A Randomized Controlled Feasibility Trial

“…ARs have therefore been suggested as potential biomarkers of whole-grain wheat and rye intakes ( 29 ). There are clear advantages of using objective markers of dietary intakes and, although not a precise measure of cereal fiber intake at an individual level, AR provides both a degree of ranking in individuals ( 28 , 29 ) and an objective marker of recent cereal fiber intake from whole wheat and rye at a group level ( 30 ). In the current trial, participants were asked to consume whole-wheat breakfast cereals, therefore consuming all parts of the grain, and the measure of AR was used solely as a measure of adherence to the intervention and not to examine any potential relation between AR and metabolic outcomes.…”