Dietary flavonoid intake in older adults: how many days of dietary assessment are required and what is the impact of seasonality?

Abstract

BackgroundWithin- and between-person variation in nutrient intake is well established, but little is known about variability in dietary flavonoid intake, including the effect of seasonality.MethodsWithin- and between-individual variability of flavonoid intake, and intake of flavonoid subclasses was examined in older adults (n = 79; mean age 70.1 y (range: 60y-80y)), using three separate 4-day weighed food records (WFR) collected approximately 4 months apart. The effects of seasonality were also examined. Mixed-effects linear regression models were used to estimate within- and between-individual variance components for flavonoids and subclasses. The number of days of dietary assessment required for a high level of hypothetical accuracy was calculated from variance ratios.ResultsWithin- and between-individual variability was high for flavonoid intake, and intake of flavonoid subclasses, with variance ratios > 1. It was calculated that six days of WFR data are required for total flavonoid intake, and between 6 and 10 days was required for flavonoid subclasses. There was no effect of seasonality for total flavonoid intake or intake of flavonoid subclasses, with the exception that flavan-3-ol and flavanone intakes which were relatively low in summer, and in summer and winter, respectively.ConclusionWhile the effects of seasonality on total flavonoid intake may be small, within- and between-individual variation associated with flavonoid intake assessment appears to be substantial across 12 days of WFR data in older adults. It is recommended that a minimum of 6 days of weighed food records are collected to minimise the impact of within- and between-individual variability on total flavonoid intake assessments in this population.Electronic supplementary materialThe online version of this article (10.1186/s12937-017-0309-7) contains supplementary material, which is available to authorized users.

Estimated Intakes of Nutrients and Polyphenols in Participants Completing the MaPLE Randomised Controlled Trial and Its Relevance for the Future Development of Dietary Guidelines for the Older Subjects

“…We could not find other data on the impact of seasonality on polyphenol content of dietary plans provided in long-term residences for older people, while more literature is available in free-living older subjects. In this regard, in the Blue Mountains Eye Study, a longitudinal study performed in Australia [35], the authors found that season did not affect the overall total flavonoid intake in a group of adult and older subjects; however, it was relatively higher in spring and lower in autumn in line with our results. Conversely, Tatsumi et al [37] showed that total antioxidant intake in a Japanese population (39-77 years) was highest in winter and lowest in summer.…”

“…A major focus in this study was polyphenols because these compounds have the potential to provide further specific benefits to the target population under study. It has been reported that there is a large variation in the polyphenol content of foods available in different periods of the year [34][35][36], and for this reason we specifically analysed recipes and ingredients used to develop seasonal menus and the results obtained showed a relatively comparable amount of these bioactive compounds (about 770 mg per day on average as TPC) among the different seasons. We could not find other data on the impact of seasonality on polyphenol content of dietary plans provided in long-term residences for older people, while more literature is available in free-living older subjects.…”

Systematic Review on Polyphenol Intake and Health Outcomes: Is there Sufficient Evidence to Define a Health-Promoting Polyphenol-Rich Dietary Pattern?

“…Table 1 shows reported data from literature focused on polyphenols intake. A total of 45 studies were found and analyzed [3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47]. Most of the studies were performed in Europe, North America and Asia (Figure 3A).…”

“…In addition, multiple administrations are also recommended when 24-h DRs are used to examine diet impact on health outcomes or other parameters. On the other hand, it has been reported that the assessment of total flavonoid intake requires at least 6 days of weighed food records, and between 6 and 10 days to determine intake of specific flavonoid subclasses with an acceptable degree of accuracy [47]. Most of the studies analyzed in the present review did not perform a multiple evaluation of food intake as highly recommended thus, an under or overestimation of total polyphenols and their classes/subclasses intake cannot be excluded.…”

Polyphenols and Human Health: The Role of Bioavailability

“…Like other flavonoids, the mean daily intake of anthocyanins can vary among countries, depending on the nutritional habits and cultural differences. It has been calculated that the daily intake of anthocyanins is between 6.8 mg per day in Brazil (where the most important dietary sources are citrus and tropical fruits) and Australia, and 133 mg per day in Italy (the main dietary sources are seasonal fruits, citrus fruits, leafy vegetables, and wine) [ 9 , 10 , 11 ].…”