Biomarkers of food intake for cocoa and liquorice (products): a systematic review

Abstract

BackgroundTo unravel true links between diet and health, it is important that dietary exposure is accurately measured. Currently, mainly self-reporting methods (e.g. food frequency questionnaires and 24-h recalls) are used to assess food intake in epidemiological studies. However, these traditional instruments are subjective measures and contain well-known biases. Especially, estimating the intake of the group of confectionary products, such as products containing cocoa and liquorice, remains a challenge. The use biomarkers of food intake (BFIs) may provide a more objective measurement. However, an overview of current candidate biomarkers and their validity is missing for both cocoa- and liquorice-containing foods.ObjectiveThe purpose of the current study was to (1) identify currently described candidate BFIs for cocoa (products) and liquorice, (2) to evaluate the validity of these identified candidate BFIs and (3) to address further validation and/or identification work to be done.MethodsThis systematic review was based on a comprehensive literature search of three databases (PubMed, Scopus and ISI web of Science), to identify candidate BFIs. Via a second search step in the Human Metabolome Database (HMDB), the Food Database (FooDB) and Phenol-Explorer, the specificity of the candidate BFIs was evaluated, followed by an evaluation of the validity of the specific candidate BFIs, via pre-defined criteria.ResultsIn total, 37 papers were included for cocoa and 8 papers for liquorice. For cocoa, 164 unique candidate BFIs were obtained, and for liquorice, four were identified in total. Despite the high number of identified BFIs for cocoa, none of the metabolites was specific. Therefore, the validity of these compounds was not further examined. For liquorice intake, 18-glycyrrhetinic acid (18-GA) was found to have the highest assumed validity.ConclusionsFor cocoa, specific BFIs were missing, mainly because the individual BFIs were also found in foods having a similar composition, such as tea (polyphenols) or coffee (caffeine). However, a combination of individual BFIs might lead to discriminating profiles between cocoa (products) and foods with a similar composition. Therefore, studies directly comparing the consumption of cocoa to these similar products are needed, enabling efforts to find a unique profile per product. For liquorice, we identified 18-GA as a promising BFI; however, important information on its validity is missing; thus, more research is necessary. Our findings indicate a need for more studies to determine acceptable BFIs for both cocoa and liquorice.Electronic supplementary materialThe online version of this article (10.1186/s12263-018-0610-x) contains supplementary material, which is available to authorized users.

Effects of Extra Virgin Olive Oil and Apples Enriched-Dark Chocolate on Endothelial Progenitor Cells in Patients with Cardiovascular Risk Factors: A Randomized Cross-Over Trial

“…Regarding changes to metabolites that classical clinical parameters do not immediately detect, recent studies strongly suggest identifying new pathways explaining the benefits of cocoa on cardiovascular [48], and our study supports this hypothesis.…”

Where to Look into the Puzzle of Polyphenols and Health? The Postbiotics and Gut Microbiota Associated with Human Metabotypes

“…[ 153 ] Therefore, the binary response of metabotypes is not accomplished, that is, the presence versus absence of unique metabolites. Although phenylvalerolactones have been proposed as biomarkers of proanthocyanidin intake, [ 154,155 ] these metabolites are intermediates in the catabolic pathway, being further metabolized to unspecific final metabolites. This means that the analysis of intermediates, including phenylvalerolactones, is influenced by many variables such as the source and concentration of proanthocyanidins, the lag period between the last intake of precursor and the sample analysis, the concomitant intake of other food compounds, etc., which lead to misleading results concerning the qualitative and quantitative production of metabolites.…”

Food intake biomarkers for green leafy vegetables, bulb vegetables, and stem vegetables: a review

“…To facilitate the identification and evaluation of new candidate BFIs, the Food Biomarker Alliance (FoodBAll) [21], a project funded by the Joint Programming Initiative a Healthy Diet for a Healthy Life, established guidelines to conduct a literature search dedicated to food intake biomarkers [25] and to evaluate their level of validation using a set of consensus criteria [26]. The guidelines were applied for all major food groups: fruit and vegetables, meats, fish, and other marine foods, dairy products, cereals and whole grains, alcoholic and non-alcoholic beverages, vegetable oils, nuts, and spices and herbs (http://foodmetabolome.org/wp3) [27][28][29][30][31][32][33][34][35][36]. The present article presents the results of the in depth exploration of possible biomarkers of intake for green leafy vegetables (lettuce, spinach, endive, and garden rocket) as well as bulb and stem vegetables (artichoke, asparagus, celery).…”