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The idea that previously unknown hazards can be readily revealed in complex mixtures such as foods is a seductive one, giving rise to the hope that data from effect-based assays of food products collected in market surveys is of suitable quality to be the basis for data-driven decision-making. To study this, we undertook a comparative study of the oestrogenicity of blinded cereal samples, both in a number of external testing laboratories and in our own facility. The results clearly showed little variance in the activities of 9 samples when using a single method, but great differences between the activities from each method. Further exploration of these findings suggest that the oestrogenic activity is likely an inherent part of the natural food matrix which the varying sample preparation methods are able to release and extract to differing degrees. These issues indicate the current poor suitability of these types of datasets to be used as the basis for consumer advice or food decision-making. Data quality must be improved before such testing is used in practice. [ABSTRACT FROM AUTHOR]

Background and objectives: The presence of endocrine disruptors in food is creating concern, and consequently, efficient methods for their identification are needed. In vitro bioassays have been developed to study endocrine properties of pure chemicals as well as mixtures. Because of their relative ease of execution and low cost, application of such techniques to whole foods is tempting. This raises a number of technical challenges. To address them, a study was commissioned in a contract laboratory offering in vitro estrogenicity testing of food products. Findings: Four different commercial and regulatory compliant cereal products were sent in blinded triplicates. Some samples were reported to be active by the laboratory. However, the results were not reproducible and very close to the 0% measurable activity. Furthermore, a statistical analysis of the raw data indicated an absence of activity. This was surprising since these products were expected to naturally contain estrogenic compounds such as the phytoestrogens lignans and flavones. However, phytoestrogens in cereals are known to occur mainly in bound, inactive, forms, suggesting that the sample preparation used in the present study was not suitable to release active estrogenic substances. This hypothesis was supported by preliminary data using a high‐resolution mass spectrometry method which did not detect any significant levels of phytoestrogens in the tested cereal extracts. Conclusions: Using a yeast‐based method, no estrogenic activity was found in breakfast cereals. However, benchmarking the bioassay data against quality criteria raised the question of the qualification of the sample preparation and bioassay used to adequately address estrogenic activity of whole foods. Significance and novelty: The quality requirements for testing whole food samples were formally addressed. The application of validated and harmonized methods for both sample preparation and bioassay testing is strongly advocated. [ABSTRACT FROM AUTHOR]

Scope This study intended to clarify whether two coffee brews, a market blend (MB) and a study blend (SB), containing equal amounts of caffeine, but differing in their contents of N-methylpyridinium, trigonelline and chlorogenic acids, differentially affect blood lipid profiles and glucose concentrations as well as blood platelet phosphodiesterase and lymphocyte energy charge potential in healthy volunteers. Methods and results In this double-blinded, randomized, controlled cross-over intervention study, 84 healthy normal-weight female and male volunteers consumed 750 mL of medium roast MB and dark roast SB coffee per day for 4 weeks. Following MB and SB coffee intervention, plasma free fatty acid concentrations equally increased ( p < 0.001) by 140 ± 187 μM and 178 ± 160 μM, respectively. Plasma glucose remained largely unchanged. Lymphocyte adenosine nucleotide analysis revealed a comparable rise in the energy charge potential, as calculated from ADP/ATP concentrations, adjusted to total adenosine nucleotides. Blood platelet phosphodiesterase activity was found decreased to about the same extent ( p < 0.001). Levels of HDL-cholesterol, adiponectin, leptin, insulin and osteopontin were found to some extent differentially influenced by MB, respectively SB coffee. Conclusion The results of this intervention study indicate that MB and SB coffees, although differing in contents of N-methylpyridinium, trigonelline and chlorogenic acids, largely exert similar biological effects as monitored by the biomarkers tested. [ABSTRACT FROM AUTHOR]