Correlations between urinary concentrations and dietary intakes of flavonols in the European Prospective Investigation into Cancer and Nutrition (EPIC) study

The Evaluation of the Phytochemical Profiles and Antioxidant and α-Glucosidase Inhibitory Activities of Four Herbal Teas Originating from China: A Comparative Analysis of Aqueous and Ethanol Infusions

“…Similarly, with aqueous extraction, Vine also exhibited the highest total flavonol content, followed by Mallotus > Rubus > Cyclocarya. The recommended daily intake of flavonol for adults is approximately 29 mg [ 36 ], and results from the total flavonol content analysis suggest that Vine tea could serve as one of the best dietary sources of flavonol among the four herbal teas. Moreover, the flavonol contents from most ethanol extracts were comparable to those of Camellia tea leaves [ 37 ], highlighting the value of ethanol extraction as a method for obtaining dietary flavonols.…”

Food frequency questionnaire is a valid assessment tool of quercetin and kaempferol intake in Iranian breast cancer patients according to plasma biomarkers

“…Apart from dietary vs. pharmacological doses [1,54], differences in correlations might be partially due to the use of different databases for flavonoid contents (taking into account missing values and variability in the composition of these compounds in foods), and intraand inter-variability in the pharmacokinetics of flavonols [1,35,57]. More importantly, short-term dietary assessments (such as 24h dietary-recall) are methods usually accompanied by stronger correlations than long-term assessments such as FFQ) [25,58]. The included food groups are not uniform across studies, and therefore, this might lead to variation in correlations.…”

“…This could be in part due to limitations of the dietary assessment using questionnaires [20], which are usually prone to random and systematic errors [21][22][23]. Moreover, plasma and urinary concentrations of flavonoids are usually affected by intra-and inter-individual variations related to absorption, intestinal-hepatic metabolism, and excretion, and therefore, these could add difficulties to the selection of a precise biomarker or led to controversies in epidemiological studies [24][25][26].…”

Evaluation of the Phytochemical Profiles, Antioxidant and α-Glucosidase Inhibitory Activities of Four Herbal Teas Originating from China: A Comparative Analysis of Aqueous and Ethanol Extraction

“…While with aqueous extraction, Vine also had the highest value of total flavonol content, followed by Mallotus > Rubus > Cyclocarya. The recommended flavonol intake is about 29 mg per day for adults [36], and results from the total flavonol content analysis suggested that Vine tea could serve as one of the best dietary supplement for flavonol intake among the four herbal teas. At the same time, the flavonol contents from most of the ethanol extracts were similar with that of Camellia tea leaf [37], which revealed that ethanol extraction method would provide valuable dietary flavonol.…”