Chronic consumption of flavanone-rich orange juice is associated with cognitive benefits: an 8-wk randomised, double-blind, placebo-controlled trial in healthy older adults

Background: Research indicates that chronic consumption of flavonoids is associated with cognitive benefits in adults with mild cognitive impairment and neurodegenerative disease, although, there has been no such studies in healthy older adults. Furthermore, the effects of commonly consumed orange juice flavanones on cognitive function remain unexplored. Objective: To investigate whether eight weeks of daily flavanone-rich orange juice consumption was beneficial for cognitive function in healthy older adults. Design: High flavanone (HF: 305mg) 100% orange juice and equicaloric low flavanone (LF: 37mg) orange flavored cordial (500ml) were consumed daily for eight weeks by thirty seven healthy older adults (mean age 67 years) according to a crossover, double blind, randomized design separated by a four week washout. Cognitive function, mood and blood pressure were assessed at baseline and follow up with standardized validated tests. Results: Global cognitive function was significantly better following eight week consumption of flavanone-rich juice relative to eight week consumption of the low flavanone control. No significant effects on mood or blood pressure were observed. Conclusions: Chronic daily consumption of flavanone-rich 100% orange juice over eight weeks is beneficial for cognitive function in healthy older adults. The potential for flavanone-rich foods and drinks to attenuate cognitive decline in ageing and the mechanisms which underlie these effects should be investigated.

Orange juice–derived flavanone and phenolic metabolites do not acutely affect cardiovascular risk biomarkers: a randomized, placebo-controlled, crossover trial in men at moderate risk of cardiovascular disease

Background: Epidemiological data suggest inverse associations between citrus flavanone intake and cardiovascular disease (CVD) risk. However, insufficient randomized controlled trial (RCT) data limit our understanding of mechanisms by which flavanones and their metabolites potentially reduce cardiovascular (CV) risk factors. Objective: We examined the effects of orange juice or a dose-matched hesperidin supplement on plasma concentrations of established and novel flavanone metabolites and their effects on CV risk biomarkers in men at moderate CVD risk. Methods: In an acute, randomized, placebo-controlled crossover trial, 16 fasted participants (aged 51-69 y) received orange juice or a hesperidin supplement (both providing 320 mg hesperidin) or control (all matched for sugar and vitamin C content). At baseline and 5 h post-intake, endothelial function (primary outcome), further CV risk biomarkers (i.e. blood pressure, arterial stiffness, cardiac autonomic function, platelet activation and NADPH oxidase gene expression) and plasma flavanone metabolites were assessed. Prior to each intervention, a diet low in flavonoids, nitrate/nitrite, alcohol and caffeine was followed and a standardized low-flavonoid evening meal was consumed. Results: Orange juice intake significantly elevated mean (± SEM) plasma concentrations of 8 flavanone (1.75 ± 0.35 µmol/L, P < 0.0001) and 15 phenolic metabolites (13.27 ± 2.22 µmol/L, P < 0.0001) compared with control at 5 h post-consumption. Despite increased plasma flavanone and phenolic metabolite concentrations, CV risk biomarkers were unaltered. Following hesperidin supplement intake, flavanone metabolites were not different to control, suggesting altered absorption/metabolism compared with the orange juice matrix. Conclusions: Following single-dose flavanone intake within orange juice, we detected circulating flavanone and phenolic metabolites collectively reaching a concentration of 15.20 ± 2.15 µmol/L but observed no effect on CV risk biomarkers. Longer-duration RCTs are required to further examine the previous associations between higher flavanone intakes and improved cardiovascular health and to ascertain the relative importance of food matrix and flavanone-derived phenolic metabolites.

A model analysis of climate and CO2 controls on tree growth in a semi-arid woodland

We used a light-use efficiency model of photosynthesis coupled with a dynamic carbon allocation and tree-growth model to simulate annual growth of the gymnosperm Callitris columellaris in the semi-arid Great Western Woodlands, Western Australia, over the past 100 years. Parameter values were derived from independent observations except for sapwood specific respiration rate, fine-root turnover time, fine-root specific respiration rate and the ratio of fine-root mass to foliage area, which were estimated by Bayesian optimization. The model reproduced the general pattern of interannual variability in radial growth (tree-ring width), including the response to the shift in precipitation regimes that occurred in the 1960s. Simulated and observed responses to climate were consistent. Both showed a significant positive response of tree-ring width to total photosynthetically active radiation received and to the ratio of modeled actual to equilibrium evapotranspiration, and a significant negative response to vapour pressure deficit. However, the simulations showed an enhancement of radial growth in response to increasing atmospheric CO2 concentration (ppm) ([CO2]) during recent decades that is not present in the observations. The discrepancy disappeared when the model was recalibrated on successive 30-year windows. Then the ratio of fine-root mass to foliage area increases by 14% (from 0.127 to 0.144 kg C m-2) as [CO2] increased while the other three estimated parameters remained constant. The absence of a signal of increasing [CO2] has been noted in many tree-ring records, despite the enhancement of photosynthetic rates and water-use efficiency resulting from increasing [CO2]. Our simulations suggest that this behaviour could be explained as a consequence of a shift towards below-ground carbon allocation.

Effects of orange juice formulation on prebiotic functionality using an in vitro colonic model sytem

A three-stage continuous fermentative colonic model system was used to monitor in vitro the effect of different orange juice formulations on prebiotic activity. Three different juices with and without Bimuno, a GOS mixture containing galactooligosaccharides (B-GOS) were assessed in terms of their ability to induce a bifidogenic microbiota. The recipe development was based on incorporating 2.75g B-GOS into a 250 ml serving of juice (65°Brix of concentrate juice). Alongside the production of B-GOS juice, a control juice - orange juice without any additional Bimuno and a positive control juice, containing all the components of Bimuno (glucose, galactose and lactose) in the same relative proportions with the exception of B-GOS were developed. Ion Exchange Chromotography analysis was used to test the maintenance of bimuno components after the production process. Data showed that sterilisation had no significant effect on concentration of B-GOS and simple sugars. The three juice formulations were digested under conditions resembling the gastric and small intestinal environments. Main bacterial groups of the faecal microbiota were evaluated throughout the colonic model study using 16S rRNA-based fluorescence in situ hybridization (FISH). Potential effects of supplementation of the juices on microbial metabolism were studied measuring short chain fatty acids (SCFAs) using gas chromatography. Furthermore, B-GOS juices showed positive modulations of the microbiota composition and metabolic activity. In particular, numbers of faecal bifidobacteria and lactobacilli were significantly higher when B-GOS juice was fermented compared to controls. Furthermore, fermentation of B-GOS juice resulted in an increase in Roseburia subcluster and concomitantly increased butyrate production, which is of potential benefit to the host. In conclusion, this study has shown B-GOS within orange juice can have a beneficial effect on the fecal microbiota.

Flavonoid-rich orange juice is associated with acute improvements in cognitive function in healthy middle-aged males

Purpose: Epidemiological evidence suggests that chronic consumption of fruit based flavonoids is associated with cognitive benefits, however, the acute effects of flavonoid rich drinks on cognitive function in the immediate postprandial period requires examination. The objective was to investigate whether consumption of flavonoid rich orange juice is associated with acute cognitive benefits over six hours in healthy middle-aged adults. Methods: Males aged 30-65 consumed a 240ml flavonoid rich (FR) orange juice (272mg) and a calorie matched placebo in a randomized, double-blind, counterbalanced order on two days separated by a two week washout. Cognitive function and subjective mood were assessed at baseline (prior to drink consumption) and 2hrs and 6hrs post consumption. The cognitive battery included eight individual cognitive tests. A standardized breakfast was consumed prior to the baseline measures, and a standardized lunch was consumed 3hrs post drink consumption. Results: Change from baseline analysis revealed that performance on tests of executive function and psychomotor speed was significantly better following the FR drink compared to the placebo. The effects for objective cognitive function were supported by significant benefits for subjective alertness following the FR drink relative to the placebo. Conclusions: These data demonstrate that consumption of flavonoid rich orange juice can acutely enhance objective and subjective cognition over the course of six hours in healthy middle-aged adults.

Long-term conditioning of soil by plantation eucalypts and pines does not affect growth of the native jarrah tree

Plant species can condition the physico-chemical and biological properties of soil in ways that modify plant growth via plant–soil feedback (PSF). Plant growth can be positively affected, negatively affected or neutrally affected by soil conditioning by the same or other plant species. Soil conditioning by other plant species has particular relevance to ecological restoration of historic ecosystems because sites set aside for restoration are often conditioned by other, potentially non-native, plant species. We investigated changes in properties of jarrah forest soils after long-term (35 years) conditioning by pines (Pinus radiata), Sydney blue gums (Eucalyptus saligna), both non-native, plantation trees, and jarrah (Eucalyptus marginata; dominant native tree). Then, we tested the influence of the conditioned soils on the growth of jarrah seedlings. Blue gums and pines similarly conditioned the physico-chemical properties of soils, which differed from soil conditioning caused by jarrah. Especially important were the differences in conditioning of the properties C:N ratio, pH, and available K. The two eucalypt species similarly conditioned the biological properties of soil (i.e. community level physiological profile, numbers of fungal-feeding nematodes, omnivorous nematodes, and nematode channel ratio), and these differed from conditioning caused by pines. Species-specific conditioning of soil did not translate into differences in the amounts of biomass produced by jarrah seedlings and a neutral PSF was observed. In summary, we found that decades of soil conditioning by non-native plantation trees did not influence the growth of jarrah seedlings and will therefore not limit restoration of jarrah following the removal of the plantation trees.

Struggles over family land? Tree crops, land and labour in Ghana's Brong-Ahafo region

Agricultural land use in much of Brong-Ahafo region, Ghana has been shifting from the production of food crops towards increased cashew nut cultivation in recent years. This article explores everyday, less visible, gendered and generational struggles over family farms in West Africa, based on qualitative, participatory research in a rural community that is becoming increasingly integrated into the global capitalist system. As a tree crop, cashew was regarded as an individual man's property to be passed on to his wife and children rather than to extended family members, which differed from the communal land tenure arrangements governing food crop cultivation. The tendency for land, cash crops and income to be controlled by men, despite women's and young people's significant labour contributions to family farms, and for women to rely on food crop production for their main source of income and for household food security, means that women and girls are more likely to lose out when cashew plantations are expanded to the detriment of land for food crops. Intergenerational tensions emerged when young people felt that their parents and elders were neglecting their views and concerns. The research provides important insights into gendered and generational power relations regarding land access, property rights and intra-household decision-making processes. Greater dialogue between genders and generations may help to tackle unequal power relations and lead to shared decision-making processes that build the resilience of rural communities.

Leaf trapping and retention of particles by holm oak and other common tree species in Mediterranean urban environments

Holm oak (Quercus ilex), a widespread urban street tree in the Mediterranean region, is widely used as biomonitor of persistent atmospheric pollutants, especially particulate-bound metals. By using lab- and field-based experimental approaches, we compared the leaf-level capacity for particles’ capture and retention between Q. ilex and other common Mediterranean urban trees: Quercus cerris, Platanus × hispanica, Tilia cordata and Olea europaea. All applied methods were effective in quantifying particulate capture and retention, although not univocal in ranking species performances. Distinctive morphological features of leaves led to differences in species’ ability to trap and retain particles of different size classes and to accumulate metals after exposure to traffic in an urban street. Overall, P. × hispanica and T. cordata showed the largest capture potential per unit leaf area for most model particles (Na+ and powder particles), and street-level Cu and Pb, while Q. ilex acted intermediately. After wash-off experiments, P. × hispanica leaves had the greatest retention capacity among the tested species and O. europaea the lowest. We concluded that the Platanus planting could be considered in Mediterranean urban environments due to its efficiency in accumulating and retaining airborne particulates; however, with atmospheric pollution being typically higher in winter, the evergreen Q. ilex represents a better year-round choice to mitigate the impact of airborne particulate pollutants.

CHP toolkit: case study of LAIe sensitivity to discontinuity of canopy cover in fruit plantations

This paper presents an open-source canopy height profile (CHP) toolkit designed for processing small-footprint full-waveform LiDAR data to obtain the estimates of effective leaf area index (LAIe) and CHPs. The use of the toolkit is presented with a case study of LAIe estimation in discontinuous-canopy fruit plantations. The experiments are carried out in two study areas, namely, orange and almond plantations, with different percentages of canopy cover (48% and 40%, respectively). For comparison, two commonly used discrete-point LAIe estimation methods are also tested. The LiDAR LAIe values are first computed for each of the sites and each method as a whole, providing “apparent” site-level LAIe, which disregards the discontinuity of the plantations’ canopies. Since the toolkit allows for the calculation of the study area LAIe at different spatial scales, between-tree-level clumpingcan be easily accounted for and is then used to illustrate the impact of the discontinuity of canopy cover on LAIe retrieval. The LiDAR LAIe estimates are therefore computed at smaller scales as a mean of LAIe in various grid-cell sizes, providing estimates of “actual” site-level LAIe. Subsequently, the LiDAR LAIe results are compared with theoretical models of “apparent” LAIe versus “actual” LAIe, based on known percent canopy cover in each site. The comparison of those models to LiDAR LAIe derived from the smallest grid-cell sizes against the estimates of LAIe for the whole site has shown that the LAIe estimates obtained from the CHP toolkit provided values that are closest to those of theoretical models.

Effects of selective logging on tropical forest tree growth

We combined measurements of tree growth and carbon dioxide exchange to investigate the effects of selective logging on the Aboveground Live Biomass (AGLB) of a tropical rain forest in the Amazon. Most of the measurements began at least 10 months before logging and continued at least 36 months after logging. The logging removed similar to 15% of the trees with Diameter at Breast Height (DBH) greater than 35 cm, which resulted in an instantaneous 10% reduction in AGLB. Both wood production and mortality increased following logging, while Gross Primary Production (GPP) was unchanged. The ratio of wood production to GPP (the wood Carbon Use Efficiency or wood CUE) more than doubled following logging. Small trees (10 cm < DBH < 35 cm) accounted for most of the enhanced wood production. Medium trees (35 cm < DBH < 55 cm) that were within 30 m of canopy gaps created by the logging also showed increased growth. The patterns of enhanced growth are most consistent with logging-induced increases in light availability. The AGLB continued to decline over the study, as mortality outpaced wood production. Wood CUE and mortality remained elevated throughout the 3 years of postlogging measurements. The future trajectory of AGLB and the forest`s carbon balance are uncertain, and will depend on how long it takes for heterotrophic respiration, mortality, and CUE to return to prelogging levels.

Effects of abscisic acid, ethylene and sugars on the mobilization of storage proteins and carbohydrates in seeds of the tropical tree Sesbania virgata (Leguminosae)

Endospermic legumes are abundant in tropical forests and their establishment is closely related to the mobilization of cell-wall storage polysaccharides. Endosperm cells also store large numbers of protein bodies that play an important role as a nitrogen reserve in this seed. In this work, a systems approach was adopted to evaluate some of the changes in carbohydrates and hormones during the development of seedlings of the rain forest tree Sesbania virgata during the period of establishment. Seeds imbibed abscisic acid (ABA), glucose and sucrose in an atmosphere of ethylene, and the effects of these compounds on the protein contents, alpha-galactosidase activity and endogenous production of ABA and ethylene by the seeds were observed. The presence of exogenous ABA retarded the degradation of storage protein in the endosperm and decreased alpha-galactosidase activity in the same tissue during galactomannan degradation, suggesting that ABA represses enzyme action. On the other hand, exogenous ethylene increased alpha-galactosidase activity in both the endosperm and testa during galactomannan degradation, suggesting an inducing effect of this hormone on the hydrolytic enzymes. Furthermore, the detection of endogenous ABA and ethylene production during the period of storage mobilization and the changes observed in the production of these endogenous hormones in the presence of glucose and sucrose, suggested a correlation between the signalling pathway of these hormones and the sugars. These findings suggest that ABA, ethylene and sugars play a role in the control of the hydrolytic enzyme activities in seeds of S. virgata, controlling the process of storage degradation. This is thought to ensure a balanced flow of the carbon and nitrogen for seedling development.

Cell wall polysaccharides from cell suspension cultures of the Atlantic Forest tree Rudgea jasminoides (Rubiaceae)

Rudgea jasminoides (Rubiaceae) is a tropical tree species native of the Atlantic Forest in the south of Brazil. Previous studies with leaf cell walls of R. jasminoides showed a different proportion of cross-linked glycans compared to what is usually reported for eudicots. However, due to the difficulties of working with whole plant organs, cell suspensions of R. jasminoides, consisting of predominantly undifferentiated cells with mainly primary cell walls, were used to examine cell walls and extracellular soluble polysaccharides (EP) released into the culture medium. Sugar composition and linkage analysis showed homogalacturonans, xylogalacturonans and arabinogalactans to be the predominant EP. In the cell wall, homogalacturonans and arabinogalactans are the major pectins, and xyloglucans and xylans are the major cross-linking glycans. The presence of xylogalacturonans in the R. jasminoides cell cultures seems to be related to the occurrence of a homogeneous cell suspension with loosely attached cells. Although all alkali extractions from the cell walls yielded amounts of xyloglucan that exceed those of the xylans, the latter was found in a proportion that is higher than what has been usually reported for primary cell walls of most eudicots. The xyloglucan from cell walls of cell suspension cultures of R. jasminoides has low fucosylation levels and high proportion of galactosyl residues, a branching pattern commonly found in storage cell-wall xyloglucans.

The role of carbohydrates in seed germination and seedling establishment of Himatanthus sucuuba, an Amazonian tree with populations adapted to flooded and non-flooded conditions

Background and Aims In the Amazonian floodplains plants withstand annual periods of flooding which can last 7 months. Under these conditions seedlings remain submerged in the dark for long periods since light penetration in the water is limited. Himatanthus sucuuba is a tree species found in the `varzea` (VZ) floodplains and adjacent non-flooded `terra-firme` (TF) forests. Biochemical traits which enhance flood tolerance and colonization success of H. sucuuba in periodically flooded environments were investigated. Methods Storage carbohydrates of seeds of VZ and TF populations were extracted and analysed by HPAEC/PAD. Starch was analysed by enzyme (glucoamylase) degradation followed by quantification of glucose oxidase. Carbohydrate composition of roots of VZ and TF seedlings was studied after experimental exposure to a 15-d period of submersion in light versus darkness. Key Results The endosperm contains a large proportion of the seed reserves, raffinose being the main nonstructural carbohydrate. Around 93% of the cell wall storage polysaccharides (percentage dry weight basis) in the endosperm of VZ seeds was composed of mannose, while soluble sugars accounted for 2.5%. In contrast, 74% of the endosperm in TF seeds was composed of galactomannans, while 22% of the endosperm was soluble sugars. This suggested a larger carbohydrate allocation to germination in TF populations whereas VZ populations allocate comparatively more to carbohydrates mobilized during seedling development. The concentration of root non-structural carbohydrates in non-flooded seedlings strongly decreased after a 15-d period of darkness, whereas flooded seedlings were less affected. These effects were more pronounced in TF seedlings, which showed significantly lower root non-structural carbohydrate concentrations. Conclusions There seem to be metabolic adjustments in VZ but not TF seedlings that lead to adaptation to the combined stresses of darkness and flooding. This seems to be important for the survival of the species in these contrasting environments, leading these populations to different directions during evolution.