Exergaming in augmented reality is tailor-made for aerobic training and enjoyment among healthy young adults.

In recent years, the use of exergaming for physical activity practice has gain in popularity but few is known about the use of augmented reality for physical activity, particularly at moderate to vigorous intensities. The present study examined the use of an exergame in augmented reality for aerobic training in healthy young adults. In a within-subject design, 18 participants (19.8 ± 1.4 years of age) have performed two physical activity sessions playing dodgeball. Indeed, they realized a classical dodgeball session and an exergaming session with an augmented reality version of dodgeball game. Physical loads and intensities were measured with accelerometers, RPE and heart sensors. Enjoyment experienced during the sessions was measured with the short version of the physical activity enjoyment scale questionnaire. Results revealed that both physical load and intensity were appropriate for aerobic training in the two conditions (i.e., classical and exergame in augmented reality) although values were significantly higher in the classical condition. Enjoyment was high in the two conditions with a higher significant value in the classical condition compared to the exergame in augmented reality condition. Put together, these results indicate that an aerobic state can be attained through both physical gameplay and its augmented reality equivalent and was associated to a high level of enjoyment among healthy young adults.

Exploring the Use of a Learning-Based Exergame to Enhance Physical Literacy, Soft Skills, and Academic Learning in School-Age Children: Pilot Interventional Study.

BACKGROUND: There is ample evidence that most children do not perform enough physical activity (PA). To address this major public health problem, the French government implemented 30 minutes of daily PA (DPA) at schools but did not provide any supplemental resources or concrete guidance. Considering both children's interest in video games and the need for teachers to complete their curriculum, the use of a learning-based exergame that combines PA and learning appears particularly relevant. OBJECTIVE: The first objective of this study was to evaluate the feasibility of implementing 30 minutes of DPA through exergaming among school-age children. The second objective was to examine the effects of an exergaming program on physical literacy, academic learning, and soft skills (motivation, self-efficacy, and concentration). METHODS: This interventional study had a pre-post design and used the Play LÜ exergame platform. The study included 79 children with a mean age of 8.9 (SD 1.2) years from grade 2 (7 years old) to grade 5 (11 years old). Play LÜ requires players to throw balls against a wall to reach a target or to activate an object and provides an interactive game area for educational activities linked to specific learning themes. After a 4-session familiarization phase during which the teachers chose to prioritize mathematics learning in 30-minute DPA sessions, students took part in DPA sessions over a period of 3 weeks with Play LÜ and a motor skills circuit behind the LÜ setup to keep them continuously active. All sessions were carried out by PA specialists. Each session started with a warm-up using the Grööve application, continued with main activities promoting mathematics learning adapted to each grade level, and ended with a 3-minute meditation for returning to a calm and serene state using the Gaïa application. Before (T0) and after (T1) the program, students completed a self-evaluation booklet to assess their levels of physical literacy, academic performance, and soft skills. RESULTS: The implementation of this exergaming program was welcomed by the school's administration, teaching staff, and parents. After the program, we observed increased scores for physical literacy (difference +2.6, percentage change +3.6%; W=933.0; P=.002; rrb=-0.39, 95% CI -0.58 to -0.16) and motivation in mathematics (+0.7, +9.8%; W=381.5; P=.005; rrb=-0.44, 95% CI -0.66 to -0.16). In addition, it is important to note that some measures progressed differently across learning levels and age groups. CONCLUSIONS: The study results indicate positive impacts of learning-based exergaming on physical literacy and motivation in mathematics among school-age children.

Relationship between Fear of COVID-19, Intolerance of Uncertainty, and Coping Strategies on University Students' Mental Health.

BACKGROUND: the mental health of students was particularly affected by the COVID-19 pandemic. The present study therefore examined the relationships between anxiety and depressive symptoms, eating-related problems, coping, fear of COVID-19, and intolerance of uncertainty. METHODS: 2139 French students of 54 universities were recruited in the different regions of France during a French lockdown (between 21 April and 3 May 2021). Six variables were measured: fear of COVID-19, intolerance of uncertainty, coping, anxiety and depressive symptoms, and eating-related problems. To explore the directions of the relationships between our variables of interest, we calculated a directed acyclic graph. RESULTS: our data highlighted the central roles of intolerance of uncertainty in students' anxiety and depressive symptoms, and the direct role of prospective intolerance of uncertainty on eating-related problems. CONCLUSIONS: these findings indicate that intolerance of uncertainty should be targeted by interventions designed to help students with high levels of anxiety, depressive symptoms, and/or eating-related problems.

Exploring the Health Effectiveness of a Physical Activity Program Co-Constructed with Students after the COVID-19 Pandemic.

BACKGROUND: University students have low levels of physical activity and high levels of sedentary behaviors that were exacerbated by the COVID-19 pandemic. Even before the pandemic, there was poor uptake of university sports activities. Therefore, it is essential to develop and test innovative programs to increase students' motivation to engage in physical activity in order to prevent any future deterioration in their general health. OBJECTIVE: This exploratory study was conducted to test the effectiveness of a physical activity program that was co-constructed with students. METHODS: First, a workshop drawing on social design methodologies and the fundamentals of physical activity programs was conducted to assess students' needs and desires in terms of physical activity. Second, the effectiveness of a program co-constructed with students on the basis of this workshop was assessed on physical and mental health parameters. The results showed that the workshop outcomes allowed the physical activity program to be tailored to meet students' expectations (e.g., session duration and type of activities). This innovative physical activity program was found to improve body image, autonomous motivation, and certain physical parameters. At the end of the 8-week program, the adherence rate was 89%, and 83% of the final respondents expressed a wish to re-enroll for the following semester. CONCLUSIONS: Involving students and considering their wishes, needs, and objectives could facilitate the development of attractive and innovative programs.

The Effect of Intervention Approaches of Emotion Regulation and Learning Strategies on Students' Learning and Mental Health.

University students are a vulnerable population, and many recent studies show that anxiety, depressive symptoms, and academic burnout have been on the increase since the beginning of the COVID-19 pandemic. These findings point to a need for interventions to reduce these difficulties. The purpose of the present study was to assess the effects of 2 formats of an innovative program on students' mental health (anxiety, depressive symptoms, and academic burnout), intolerance of uncertainty, learned helplessness, and learning. Our sample was composed of 105 university students, recruited on a voluntary basis. They were divided into 3 groups: online intervention group (n = 36), face-to-face intervention group (n = 32), and control group (n = 37). The following variables were measured through online questionnaires: anxiety and depressive symptoms, academic burnout, intolerance of uncertainty, learned helplessness, perceived social support, learning strategies, and beliefs. There were 2 assessments 10 weeks apart (ie, before and after the program in the case of the 2 intervention groups). We performed nonparametric analyses to run comparisons between the 2 assessment timepoints in each group. Results showed that participants in the 2 intervention groups had lower levels of learned helplessness and intolerance of uncertainty at the end of the program. Furthermore, participants in the face-to-face group reported higher levels of perceived social support, academic self-efficacy, and help-seeking strategies. The present study highlighted the benefits of our innovative program, especially its face-to-face format.Clinical Trial - ID: NCT04978194.

Can an Eight-Session Multicomponent Physical Exercise Program Reduce Fall Risk and Fear of Falling among the Elderly?

In older populations, falls are responsible for decrease autonomy and increased pain and injuries. With aging, fall risk is multifactorial and associated with sarcopenia, impaired balance, falls themselves and psychological factors such as fear of falling. The objectives of the present study were: (a) to test the effects of a short multicomponent physical exercise program on fall risk and fear of falling; and (b) to analyze the relationship between fall risk and fear of falling. The participants were thirty-five older persons who were engaged in an eight-session physical exercise program. Balance (i.e., One-leg Balance Test, and Functional Reach Test), lower-limb endurance (i.e., Wall-sit Test) and fear of falling were measured before and after the multicomponent physical exercise program. Results indicated an increase in balance and a diminution of fear of falling after the end of the physical exercise program (p < 0.05). The program has an effect on lower limb endurance (p > 0.05). Gains in balance were correlated to the diminution of fear of falling (p < 0.05). An 8-week multicomponent physical exercise program based on balance is efficient to reduce fall risk and fear of falling among the elderly.

Promoting Physical Activity Among University Students During the COVID-19 Pandemic: Protocol for a Randomized Controlled Trial.

BACKGROUND: Since the beginning of the COVID-19 pandemic, sanitary context and e-learning have greatly modified student lifestyles and led to deteriorations in their mental health. An increase in anxiety and depressive symptoms and sedentary behaviors, reduction in physical activity, and a stronger tendency to move toward unhealthy diet have been demonstrated. This finding highlights the need for innovative interventions to promote healthy lifestyle among students. OBJECTIVE: This research protocol aims to evaluate the effects of an intervention program on the lifestyle and psychological state of students. METHODS: Students from University of Nîmes were recruited and randomly assigned to 1 of 2 following conditions: an intervention group and a control group. Participants in the intervention group were engaged in an 8-week physical activity program. Prior to the start of the program, design-based innovative workshops were conducted with participants to ensure that the program was co-constructed by the users and met their specific needs. Students in the control group did not receive any intervention. For each group, measures of physical activity, sedentary time, anthropometric data, sleep, physical condition, and psychological variables (eg, anxiety, depression, motivation, body appreciation, perceived control, well-being) were conducted at baseline and 9 weeks later. RESULTS: A total of 110 participants were initially included. Reporting of the results is projected for the spring of 2022. CONCLUSIONS: It is anticipated that this innovative intervention co-constructed by pairs will promote a healthier lifestyle and psychological health in students. There is every reason to believe that a mobilized co-construction approach is a promising strategy to limit unhealthy habits and promote physical activity while increasing motivation. The development and evaluation of interventions to address the specific needs of university students is essential and could be transferred to other vulnerable populations such as people with chronic diseases or older people. TRIAL REGISTRATION: ClinicalTrials.gov NCT05019482; https://clinicaltrials.gov/ct2/show/NCT05019482. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/36429.

Vitamin D Supplementation on Carotid Remodeling and Stiffness in Obese Adolescents.

Obesity is associated with vitamin D (VD) deficiency and arterial stiffness. This randomized control trial assessed the effects of VD supplementation during a weight-loss program on carotid intima-media thickness (IMT) and carotid compliance in obese adolescents. Participants were randomly assigned to receive either a 12-week lifestyle program with VD supplementation (n = 13), a lifestyle program without VD supplementation (n = 13) or a control group composed of normal-weight adolescents (n = 18). Serum total and free 25-hydroxyvitamin D (25(OH)D), IMT and carotid compliance were measured before and after the trial. Insufficiency in 25(OH)D concentration was found in 73% of obese participants compared to 22% among controls. Obese adolescents had lower free 25(OH)D and displayed higher IMT but lower carotid compliance than controls. Free 25(OH)D and IMT were negatively correlated in adolescents displaying VD insufficiency at baseline. After three months, total and free 25(OH)D increased in both groups. The changes of IMT and carotid compliance were similar between groups. The changes in IMT were correlated with the changes in total 25(OH)D in obese adolescents with VD insufficiency at baseline (r = -0.59, p = 0.03). While the lifestyle program with VD supplementation did not affect carotid compliance, IMT reduction was improved in obese adolescents.

Two Years and Four Time Points: Description of Emotional State and Coping Strategies of French University Students during the COVID-19 Pandemic.

While it is now clear that the COVID-19 pandemic has had a major impact on the mental health of individuals, especially the most vulnerable ones such as students, we have very little knowledge about the long-term consequences. The objective of this study was to compare the mental health and coping of French university students during the different phases of the pandemic in the first 2 years. To this end, French university students were evaluated at four time points: during France's first lockdown (April-May 2020; nT1 = 1357), the period after lockdown (June 2020; nT2 = 309), 1 year after the first lockdown, which was also a lockdown period (April-May 2021; nT1' = 2569); and 1 year after the end of the first unlock (June 2021; nT2' = 1136). Anxiety and depressive symptoms, coping and concerns were measured. In order to compare scores between the lockdown and unlock periods within the same year, paired samples t-tests were performed. To compare scores between the 2 years for different participants, independent samples t-tests were conducted. Our results showed that maladaptive strategies, concerns and symptoms were higher during lockdown periods, compared with unlock periods. In addition, symptom levels were higher in the second year of the pandemic compared with the first one. These argue that the psychological effects of COVID-19 were exacerbated by lockdowns but also by time. This highlights the need for more attention to be paid to students' mental health.

Effects of an online self-help intervention on university students' mental health during COVID-19: A non-randomized controlled pilot study.

The COVID-19 pandemic has had a major impact on university students, particulary on their mental health. However, little is yet known about how to prevent and/or reduce this impact. Prior to COVID-19, some studies have shown that online stress management programs were successful enough to improve students' mental health and stress adjustment strategies, suggesting that these interventions should be further developed during the pandemic. Our study explored the effects on mental health of an online program that targeted stress management and learning. A total of 347 university students were initially recruited to take part in a non-randomized controlled study. After dropout, our final sample consisted of 114 participants, divided into two groups: an intervention group (participants who took part in the program) and the control group (participants who did not participate in the program). The variables measured were: anxiety and depressive symptoms, academic burnout, learned helplessness, and coping strategies. Means comparisons between baseline (T0) and an assessment at 8 weeks (T1) revealed reductions in anxiety symptoms and learned helplessness in the intervention group, but not in the control group. Our pilot study reports promising effects of an online program on students' psychological state.

Psychological Vulnerability of French University Students during the COVID-19 Pandemic: A Four-Wave Longitudinal Survey.

BACKGROUND: Many studies have highlighted the negative mental health consequences of lockdowns. However, to date, we do not know how these consequences change over time. The first objective of the present study was to track changes in adjustment strategies and clinical issues among French university students at different times of the pandemic. The second objective was to investigate the psychological and situational factors contributing to students' anxiety and depressive symptoms. METHOD: This cohort study was conducted between 23 April and 11 December 2020. Measurements were performed four times: during France's first national lockdown, during the period after lockdown, when universities were open, and finally during the second national lockdown. A total of 1294 university students were initially included, and 91 students completed the four measurement points over a 7-month period. Coping strategies (with the Brief-COPE), health concerns (with two questions), anxiety and depressive symptoms (with the HADS) were measured. RESULTS: Results showed an evolution over time of anxiety (χ2 = 21.59 ***) and depressive (χ2 = 29.73 ***) symptoms. Depressive symptoms are significantly higher during lockdown periods compared to unlockdown periods. Anxiety symptoms are likewise particularly high during the two lockdowns, but also when the universities reopen. At different times, anxiety and depressive symptoms were positively associated with maladaptive strategies, such as the self-blame (rho between 0.33 and 0.51) and negatively with adaptive strategies, such as the positive reframing (rho between -0.23 and -0.44). CONCLUSIONS: The trajectory of anxiety, which is elevated even in the absence of lockdown, raises concerns about the long-term effects of the pandemic on these symptoms.

University Students' Lifestyle Behaviors during the COVID-19 Pandemic: A Four-Wave Longitudinal Survey.

Many studies have highlighted the impact of lockdowns on the lifestyle of university students. We do not, however, know how these lifestyles have changed over the course of the COVID-19 pandemic. The objective of the present study was to describe changes in the levels of physical activity, sedentary behaviors, and alcohol consumption in French university students during different periods of the pandemic. This cohort study was conducted between 23 April and 11 December 2020. Measurements were performed four times: Twice during two successive lockdowns and twice during the intervening period. A total of 1294 university students were initially included, and 91 students completed the four measurement points over a seven-month period. Alcohol consumption, physical activity, and sedentary behaviors were measured. The results revealed high levels of physical activity during the first lockdown, but a subsequent decline during the pandemic that was partly explained by time. The pandemic had a positive effect on alcohol consumption. Sedentary levels were higher during both lockdowns, and sedentary behaviors tended to persist over time. This study raises concerns about the long-term effects of the pandemic on students' health and lifestyle. The preponderance of distance learning should be reconsidered, given the negative impact of physical inactivity and sedentary behavior on long-term health, especially in young adults.

Effect of vitamin D supplementation on microvascular reactivity in obese adolescents: A randomized controlled trial.

BACKGROUND AND AIM: Childhood obesity is associated with vitamin D (VD) deficiency and vascular dysfunction. Considering evidence indicates that VD may improve vascular function, this study, for the first time, assessed the effect of VD supplementation on microvascular reactivity in obese adolescents (OA). METHODS AND RESULTS: This randomized controlled trial included 26 OA, receiving fruit juice with (n = 13) or without VD (4000 IU/d; n = 13) over a 3-month lifestyle program, as well as 23 normal-weight adolescents (controls). The primary outcome was the pre-to-post-program change in microvascular reactivity determined by laser speckle contrast imaging with acetylcholine and sodium nitroprusside iontophoresis. Changes in 25 hydroxyvitamin D (25(OH)D), flow-mediated dilation (FMD), nitrate-mediated dilation (NMD), insulin resistance (HOMA-IR) and inflammatory markers (C-reactive protein [CRP]) were monitored. At inclusion, in comparison to controls, OA exhibited lower total and free 25(OH)D, impaired microvascular responses, and impaired FMD, but similar NMD. After the lifestyle program, total and free 25(OH)D increased in all OA, with a greater increase in those receiving VD supplements. HOMA-IR and CRP decreased in all OA. Neither FMD nor NMD were altered in either group. Endothelium-dependent microvascular reactivity only increased in the VD-supplemented group, reaching values comparable to that of controls. Similar results were found when analyzing only OA with a VD deficiency at baseline. CONCLUSION: VD supplementation during a lifestyle program attenuated microvascular dysfunction in OA without altering macrovascular function. REGISTRATION NUMBER FOR CLINICAL TRIAL: NCT02400151.

The Psychological Vulnerability of French University Students to the COVID-19 Confinement.

Even before the current pandemic, university students were known to have high levels of hassles, anxiety, and depressive symptoms. In all probability, the advent of COVID-19 has substantially raised these levels. The present study measured the emotional state of university students during lockdown and identified the relevant situational and psychological factors. To this end, 1,297 French university students were assessed during lockdown, which lasted from 16 March to 11 May in France. Situational factors included the belief that lockdown was compromising their future job prospects, COVID-19 symptoms, and health concerns. Psychological factors included students' implicit theory of emotion, and the coping strategies they used during lockdown. We explored the extent to which these factors were associated with levels of hassles, anxiety, and depressive symptoms. Results indicated that students' belief that lockdown was compromising their future job prospects was positively related to hassles (r = .34, p < .001), while concerns about their own health and that of relatives were positively associated with anxiety (r = .37 and .34; p < .001). In addition, use of the positive reframing coping strategy mediated the effect of students' implicit theory of emotion on their depressive symptoms. Even though the national lockdown is now over, the pandemic will continue to have a major impact on university students over the coming months. It is therefore essential for universities to provide them with adequate psychological support.

Association of organic food consumption with obesity in a nationally representative sample.

The increased prevalence and adverse health consequences of obesity have made it one of the leading public health issues in recent years. Importantly, several epidemiological studies have revealed significant associations between BMI and organic food consumption. However, although these studies have suggested that this factor holds promise to prevent obesity, they all suffer from methodological limitations, including self-reporting methods to assess BMI, not controlling for potential confounding factors or using a non-representative sample. Moreover, all were restricted to an adult sample. We present the results of a cross-sectional epidemiological study assessing the association of organic food consumption with BMI and obesity in a representative lifespan French sample (INCA3 study). Objective methods were used to measure BMI, and several potentially confounding variables were controlled for. In total, 1775 children and adolescents and 2121 adults underwent anthropometric measurements and completed questionnaires concerning their dietary habits and lifestyle. Unadjusted models systematically revealed negative associations between organic food consumption and both BMI and obesity across all age groups. These associations tended to remain statistically significant even after controlling for several confounding variables concerning socio-economic status, quality of the diet and physical activity. The effect sizes were, however, small. These data confirm the association between organic food consumption and obesity during both childhood and adulthood. Evidence from randomised controlled trials is required to investigate causality between organic food consumption and lower BMI or obesity rate.

[Pilot study on the effects of an adapted physical activity program focused on the quality of life and risk indicators for falls in independent dwelling-women over 65 years]. / Étude pilote portant sur les effets d'un programme d'activités physiques adaptées sur la qualité de vie et les indicateurs du risque de chute chez des femmes autonomes âgées de plus de 65 ans.

Falls can have multiple detrimental consequences in the elderly, and this is particularly relevant for women. To prevent the risk of falling, intervention programmes based on physical exercises focusing on balance appear to be the most efficient, which explains the multiplication of this type of action at the local level. However, these actions are very rarely evaluated. METHODS: Our sample consists of 26 women (75.0 ± 6.7 years old), randomly assigned to two groups: an intervention group (GI) that has benefited from a balance-oriented adapted physical activity (APA) program focused on balance and conducted in an associative structure; and a control group (GC). Our study aims to evaluate different parameters such as physical (functional mobility, balance), subjective (balanced confidence) and health (quality of life) indicators in women over 65 years of age, living independently at home. RESULTS: In people completing the program, we observed an improvement in equilibrium capabilities (significant increase in POMA score; p < 0.05), in balance and functional mobility (significant decrease in TUG score; p < 0.01) and in balance confidence (significant increase in ABC-S; p < 0.05). CONCLUSION: The implementation of a short programme by the associative structure seems to be an interesting approach for the prevention of falls in autonomous elderly women.

Fat-soluble micronutrients and metabolic syndrome.

PURPOSE OF REVIEW: Metabolic syndrome (MetS) is associated with increased risk of obesity, type 2 diabetes mellitus and cardiovascular diseases. MetS prevalence has been associated with diet inadequacy. Conversely, the cumulative incidence of MetS has been inversely associated with a Mediterranean-style diet that includes many different health-beneficial nutrients. Adherence to a Mediterranean-style diet could reduce or at least stabilize metabolic risk factors. RECENT FINDINGS: Low serum level of fat-soluble micronutrients, such as carotenoids, vitamin (vit) A, D and E, has been linked to MetS. Fat-soluble micronutrients could contribute to prevent MetS thanks to their antioxidant and anti-inflammatory properties (vit E, carotenoids) or to their central role as hormone regulators (vit D) and/or lipid metabolism and glucose homeostasis sensors (vit D and E). SUMMARY: This review summarizes recent epidemiological studies linking fat-soluble micronutrients to MetS and highlights new evidence on their mechanisms of actions.

A Combination of Single-Nucleotide Polymorphisms Is Associated with Interindividual Variability in Cholecalciferol Bioavailability in Healthy Men.

BACKGROUND: Most people require dietary vitamin D to achieve the recommended concentration of 25-hydroxyvitamin D [25(OH)D] in the blood. However, the response to vitamin D supplementation is highly variable among individuals. OBJECTIVE: We assessed whether the variability in cholecalciferol bioavailability was associated with single-nucleotide polymorphisms (SNPs) in candidate genes. METHODS: In a single-group design, 39 healthy adult men with a mean ± SD age of 33 ± 2 y and mean ± SD body mass index (in kg/m2) of 22.9 ± 0.3 were genotyped with the use of whole-genome microarrays. After an overnight fast, plasma 25(OH)D status was measured, and the subjects then consumed a meal that provided 5 mg cholecalciferol as a supplement. Plasma chylomicron cholecalciferol concentration was measured over 8 h, and cholecalciferol response was assessed by calculating the postprandial area under the curve. Partial least squares regression was used to test the association of SNPs in or near candidate genes (61 genes representing 3791 SNPs) with the postprandial cholecalciferol response. RESULTS: The postprandial chylomicron cholecalciferol concentration peaked at 5.4 h. The cholecalciferol response was extremely variable among individuals (CV: 47%). It correlated with the chylomicron triglyceride (TG) response (r = 0.60; P < 0.001) but not with the fasting plasma 25(OH)D concentration (r = 0.04; P = 0.83). A significant (P = 1.32 × 10-4) partial least squares regression model that included 17 SNPs in 13 genes (including 5 that have been associated with chylomicron TG response) was associated with the variance in the cholecalciferol response. CONCLUSION: In healthy men, there is a high interindividual variability in cholecalciferol bioavailability that is associated with a combination of SNPs located in or near genes involved in both vitamin D and lipid metabolism. This trial was registered at clinicaltrials.gov as NCT02100774.

Pinoresinol of olive oil decreases vitamin D intestinal absorption.

Enriching oils, such as olive oil, could be one solution to tackle the worldwide epidemic of vitamin D deficiency and to better fit with omega 3 (DHA) recommendations. However, data regarding the interactions occurring at the intestinal level between vitamin D and phenols from olive oil are scarce. We first determined the effect of polyphenols from a virgin olive oil, and a virgin olive oil enriched with DHA, on vitamin D absorption in rats. We then investigated the effects of 3 main olive oil phenols (oleuropein, hydroxytyrosol and pinoresinol) on vitamin D uptake by Caco-2 cells. The presence of polyphenols in the olive oil supplemented with DHA inhibited vitamin D postprandial response in rats (-25%, p<0.05). Similar results were obtained with a mix of the 3 polyphenols delivered to Caco-2 cells. However, this inhibitory effect was due to the presence of pinoresinol only. As the pinoresinol content can highly vary between olive oils, the present results should be taken into account to formulate an appropriate oil product enriched in vitamin D.

Micellar lipid composition affects micelle interaction with class B scavenger receptor extracellular loops.

Scavenger receptors (SRs) like cluster determinant 36 (CD36) and SR class B type I (SR-BI) play a debated role in lipid transport across the intestinal brush border membrane. We used surface plasmon resonance to analyze real-time interactions between the extracellular protein loops and various ligands ranging from single lipid molecules to mixed micelles. Micelles mimicking physiological structures were necessary for optimal binding to both the extracellular loop of CD36 (lCD36) and the extracellular loop of SR-BI (lSR-BI). Cholesterol, phospholipid, and fatty acid micellar content significantly modulated micelle binding to and dissociation from the transporters. In particular, high phospholipid micellar concentrations inhibited micelle binding to both receptors (-53.8 and -74.4% binding at 0.32 mM compared with 0.04 mM for lCD36 and lSR-BI, respectively, P < 0.05). The presence of fatty acids was crucial for micelle interactions with both proteins (94.4 and 81.3% binding with oleic acid for lCD36 and lSR-BI, respectively, P < 0.05) and fatty acid type substitution within the micelles was the component that most impacted micelle binding to the transporters. These effects were partly due to subsequent modifications in micellar size and surface electric charge, and could be correlated to micellar vitamin D uptake by Caco-2 cells. Our findings show for the first time that micellar lipid composition and micellar properties are key factors governing micelle interactions with SRs.