K Kent

Estimation of Flavonoid Intake in Older Australians: Secondary Data Analysis of the Blue Mountains Eye Study

Flavonoids, consumed in plant-based foods, have been linked to risk reduction of cancers, cardiovascular, and neurodegenerative diseases. The paucity of information on dietary sources and quantities of flavonoid intake in older adults limits interpretation of epidemiological studies that link flavonoid intake with health outcomes in this population. It was our aim to describe total flavonoid intake, including flavonoid subclasses, in older Australians and to identify rich and commonly consumed sources of flavonoids in this age group. Twelve days of weighed food record dietary data from a subsample of the Blue Mountains Eye Study baseline cohort study of older Australians (n = 79) was analyzed using the US Department of Agriculture flavonoid database. Mean intake of flavonoids was estimated to be 683 mg/day (SD = 507) of which flavan-3-ols contributed 92%, followed by flavonols (4%), flavanones (3%), and flavones (<1%). Black tea was the major flavonoid source, providing 89% of total flavonoid intake. No differences in intake between genders were identified. Dietary intake of flavonoids and flavonoid subclasses in older Australians is similar to the one other estimation of intake in Australian older adults and confirms the types of foods that contribute to flavonoid intake among this sample of older Australians.

Acute reduction in blood pressure following consumption of anthocyanin-rich cherry juice may be dose-interval dependant: a pilot cross-over study

Abstract A pilot cross-over study assessed the acute effects on blood pressure and plasma biomarkers associated with consumption of a 300 ml anthocyanin-rich fruit juice, provided in differing dose-intervals. Young adults (n = 6) and older adults (n = 7) received in random order, either a single 300 ml dose or 3 × 100 ml doses of high-flavonoid cherry juice provided at 0, 1 and 2 h. Blood pressure and plasma levels of phenolic metabolites were measured at 0, 2 and 6 h.The single 300 ml dose of cherry juice resulted in a significant reduction in systolic (p = 0.002), and diastolic blood pressure (p = 0.008) and heart-rate (p = 0.033) 2 h after consumption, before returning to baseline levels at 6 h post-consumption. The 3 × 100 ml dose provided over 2 h did not result in significant blood pressure reductions. Plasma phenolic metabolites increased at 2 and 6 h; however, fluctuations were higher after the single 300 ml dose in older adults. These findings have implications for design of intervention studies that investigate vascular effects associated with flavonoid-rich foods.

A systematic review of food composition tools used for determining dietary polyphenol intake in estimated intake studies

Translating food intake data into phytochemical outcomes is a crucial step in investigating potential health benefits. The aim of this review was to examine the tools for determining dietary-derived polyphenol intakes for estimated intake studies. Published studies from 2004 to 2014 reporting polyphenol food composition information were sourced with 157 studies included. Six polyphenol subclasses were identified. One quarter of studies (n=39) reported total flavonoids intake with 27% reporting individual flavonoid compounds. Assessing multiple compounds was common with approximately 10% of studies assessing seven (n=13), six (n=12) and five (n=14) subclasses of polyphenol. There was no pattern between reported flavonoids compounds and subclass studied. Approximately 60% of studies relied on publicly accessible food composition data to estimate dietary polyphenols intake with 33% using two or more tools. This review highlights the importance of publicly accessible composition databases for estimating polyphenol intake and provides a reference for tools available globally.

Anthocyanin-rich plum juice reduces ambulatory blood pressure but not acute cognitive function in younger and older adults: A pilot cross-over dose-timing study

Consumption of anthocyanins from fruit sources may exert protection against hypertension and improve cognition. However, the effect of dose timing in studies is rarely considered. We hypothesized that timed-dose consumption of juice from an anthocyanin-rich Japanese plum variety (Queen Garnet plum, QGP) will have acute and dose-timing effects on cardiovascular responses, cognition, and urinary anthocyanin excretion profiles. Our study objective was to investigate the impact of plum juice on these health parameters. Twelve older (65+ years) and 12 younger (18-45 years) adults participated in an acute crossover study. Participants received, randomly, either 1 × 300 mL or 3 × 100 mL plum juice over 3 hours on 2 different occasions with a 2-week washout period. A battery of cognitive tasks was administered at 0 and 6 hours on each study day. Blood pressure (BP) and urinary anthocyanin/metabolite excretion profiles were measured over 24 hours. Area under the curve for BP was calculated (0-6 hours). A significant reduction in BP and cardiovascular responses was observed in both age groups which was more obvious in the older age group on the single dose for systolic BP, diastolic BP, mean arterial pressure, and heart rate (P values = .035, .028, .017, and .006, respectively). No significant difference was observed between dose-timing regimens for either age group. There was no observed effect on cognition. Native QGP anthocyanins, as well as methylated/glucuronidated metabolites, were detected in urine with no significant differences between age groups or dose timing. High-anthocyanin plum juice significantly reduced BP, but dose timing did not appear to be a significant factor in the potential acute BP-lowering effect of QGP juice.

Dietary phytochemical intake from foods and health outcomes: a systematic review protocol and preliminary scoping

Introduction Dietary phytochemicals are found in plant-based foods such as fruits, vegetables and grains and may be categorised in a nested hierarchical manner with many hundred individual phytochemicals identified to date. To associate phytochemical intakes with positive health outcomes, a fundamental step is to accurately estimate the dietary phytochemical intake from foods reported. The purpose of this systematic review protocol is to describe the process to be undertaken to summarise the evidence for food-based dietary phytochemical intakes and health outcomes for adults. Methods and analysis The review will be undertaken following the PRISMA guidelines and the Cochrane Handbook for Systematic Reviews of Interventions using the Review Manager software. Phytochemical subclasses (phenolic acids, flavanols, etc) will be used to search for relevant studies using the Web of Science and Scopus scientific databases. The retrieved studies will be screened based on inclusion of natural whole food items and health outcomes. Phytochemical studies related to cardiovascular disease, cancer, overweight, glucose tolerance, digestive, reproductive, macular and bone health and mental disorders, fatigue and immunity will be examined based on prior scoping. The evidence will be aggregated by the food types and health outcomes. Comparison of differences in the outcomes for randomised controlled trials and observational studies will be undertaken. The strength of the review lies in its focus on whole food items and health conditions rather than one type of phytochemical related to one single health condition. Subgroup and sensitivity analyses will be conducted where an adequate number of publications are found per phytochemical subclass. Dissemination By comparing the outcomes from experimental and observational studies, the review will determine whether the overall conclusions related to the phytochemical subclasses are the same between study types for the identified health conditions. This is useful to public health policymakers and health professionals alike. Trial registration number #CRD42014015610.

Development, validation and reproducibility of a food frequency questionnaire to measure flavonoid intake in older Australian adults

AIM To develop and assess the validity and reproducibility of a food frequency questionnaire (FFQ) to measure total flavonoid intake, and individual flavonoid subclasses, in older adults. METHODS Retrospective analysis of flavonoid intake in older adults informed the development of a FFQ to measure flavonoid intake and determine the flavonoid subclasses consumed (anthocyanins, flavan-3-ols, flavones, flavonols and flavanones). Older adults (n = 42, mean age 75.3 ± 8.6 years) attended two interviews 1 month apart where anthropometrics (height and weight), blood pressure (BP), demographic data and a 93-item self-administered FFQ were collected. A 4-day food record (FR) was randomly administered between the two interview dates, and each food item was assigned a flavonoid and flavonoid subclass content using the United States Department of Agriculture flavonoid database. The criterion validity and reproducibility of the FFQ was assessed against a 4-day FR using the Wilcoxon signed-rank sum test, Spearmans correlation coefficient (r), Bland-Altman Plots and Cohens kappa. RESULTS Total flavonoid intake was determined (median intake FFQ = 919.3 mg/day, FR = 781.4 mg/day). Tests of validity indicated that the FFQ consistently overestimated total flavonoid intake compared with the 4-day FR. There was a significant difference in estimates between the FFQ and the 4-day FR for total flavonoid intake (Wilcoxon signed-rank sum P < 0.001; Bland-Altman plots indicated large bias and wide limits of agreement), but they were well correlated (Spearmans r 0.93, P < 0.001; Cohens kappa κ = 0.619, P < 0.001). For individual flavonoid subclasses, the tests of validity indicated greater discrepancy compared with 4-day FR. The FFQ showed high reproducibility for estimating total flavonoid intake (FFQ1vsFFQ2: Wilcoxon signed-rank sum test, P > 0.05; Spearmans r 0.91, P < 0.001; Bland-Altman plots visually showed small, non-significant bias and wide limits of agreement; and Cohens kappa κ = 0.619, P < 0.001), with a small mean percentage difference (6.7%). For individual flavonoid subclasses, the tests of reproducibility between FFQ1 and FFQ2 showed similarly high reproducibility. CONCLUSIONS The developed FFQ appears suitable for satisfactorily ranking individuals according to total flavonoid intake. The FFQ shows limitations for estimating absolute total flavonoid intake and intake of flavonoid subclasses in comparison to a 4-day FR in terms of overestimating intake. Refinement and further validation of this tool may be required.

Relative Validity and Reproducibility of an Interviewer Administered 14-Item FFQ to Estimate Flavonoid Intake Among Older Adults with Mild-Moderate Dementia

ABSTRACT There is a large burden on researchers and participants when attempting to accurately measure dietary flavonoid intake using dietary assessment. Minimizing participant and researcher burden when collecting dietary data may improve the validity of the results, especially in older adults with cognitive impairment. A short 14-item food frequency questionnaire (FFQ) to measure flavonoid intake, and flavonoid subclasses (anthocyanins, flavan-3-ols, flavones, flavonols, and flavanones) was developed and assessed for validity and reproducibility against a 24-hour recall. Older adults with mild-moderate dementia (n = 49) attended two interviews 12 weeks apart. With the assistance of a family carer, a 24-h recall was collected at the first interview, and the flavonoid FFQ was interviewer-administered at both time-points. Validity and reproducibility was assessed using the Wilcoxon signed-rank sum test, Spearman’s correlation coefficient, Bland-Altman Plots, and Cohen’s kappa. Mean flavonoid intake was determined (FFQ1 = 795 ± 492.7 mg/day, 24-h recall = 515.6 ± 384.3 mg/day). Tests of validity indicated the FFQ was better at estimating total flavonoid intake than individual flavonoid subclasses compared with the 24-h recall. There was a significant difference in total flavonoid intake estimates between the FFQ and the 24-h recall (Wilcoxon signed-rank sum p < 0.001; Bland-Altman plots indicated large bias and wide limits of agreement), but they were well correlated (Spearman’s correlation coefficient r = 0.74, p < 0.001; Cohen’s kappa κ = 0.292, p < 0.001). The FFQ showed good reproducibility, with a small mean percentage difference (12.6%). The Wilcoxon signed-rank sum test showed no significant difference, Spearman’s correlation coefficient indicated excellent reliability (r = 0.75, p < 0.001), Bland-Altman plots visually showed small, nonsignificant bias and wide limits of agreement, and Cohen’s kappa indicated fair agreement (κ = 0.429, p < 0.001). A 14-item FFQ developed to easily measure flavonoid intake in older adults with dementia demonstrates fair validity against a 24-h recall and good reproducibility.

A systematic literature review of the effect of anthocyanins on gut microbiota populations

BACKGROUND Evidence has shown that anthocyanins, a subclass of polyphenol, are metabolised in the gut, modulate bacterial species and exert bioactive effects through this interaction. METHODS A systematic literature review was undertaken to determine the level of current evidence for the association between anthocyanin intake and changes in gut microbiota populations. The studies included were also assessed for the different techniques used in microbiota determination. Following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, scientific databases, including Scopus, PubMed, ScienceDirect, Web of Science and MEDLINE, were searched up to June 2017. Details on population/sample, study design, intervention/control, dosage and method of microbiota determination were extracted. RESULTS Six studies (three in vitro, two animal and one human trials) were included in the review, which showed that anthocyanins induced a significant proliferative effect on Bifidobacterium spp., known for their wide use in probiotics and for the treatment of irritable bowel syndrome. There was also an observed inhibition of Clostridium histolyticum, which was shown to be pathogenic in humans. The depth of analysis is an important consideration for the choice of microbiota determination technique with respect to a comprehensive, high-resolution microbiota analysis or analysis of the main microbiota taxa. CONCLUSIONS Very limited research has been carried out in the area of anthocyanins and gut microbiota; beneficial effects have generally been observed, and further clinical trials in humans are needed to confirm changes to gut microbes in relation to dietary anthocyanin intake and potential health benefits.