Endocannabinoid levels in plasma and neurotransmitters in the brain: a preliminary report on patients with a psychotic disorder and healthy individuals.

BACKGROUND: Interactions between the endocannabinoid system (ECS) and neurotransmitter systems might mediate the risk of developing a schizophrenia spectrum disorder (SSD). Consequently, we investigated in patients with SSD and healthy controls (HC) the relations between (1) plasma concentrations of two prototypical endocannabinoids (N-arachidonoylethanolamine [anandamide] and 2-arachidonoylglycerol [2-AG]) and (2) striatal dopamine synthesis capacity (DSC), and glutamate and y-aminobutyric acid (GABA) levels in the anterior cingulate cortex (ACC). As anandamide and 2-AG might reduce the activity of these neurotransmitters, we hypothesized negative correlations between their plasma levels and the abovementioned neurotransmitters in both groups. METHODS: Blood samples were obtained from 18 patients and 16 HC to measure anandamide and 2-AG plasma concentrations. For all subjects, we acquired proton magnetic resonance spectroscopy scans to assess Glx (i.e. glutamate plus glutamine) and GABA + (i.e. GABA plus macromolecules) concentrations in the ACC. Ten patients and 14 HC also underwent [18F]F-DOPA positron emission tomography for assessment of striatal DSC. Multiple linear regression analyses were used to investigate the relations between the outcome measures. RESULTS: A negative association between 2-AG plasma concentration and ACC Glx concentration was found in patients (p = 0.008). We found no evidence of other significant relationships between 2-AG or anandamide plasma concentrations and dopaminergic, glutamatergic, or GABAergic measures in either group. CONCLUSIONS: Our preliminary results suggest an association between peripheral 2-AG and ACC Glx levels in patients.

The association between adherence to the EAT-Lancet diet and cognitive ageing.

BACKGROUND: The EAT-Lancet commission has proposed a dietary pattern that is both sustainable and healthy. However, the impact of this diet on cognition in older adults remains unexplored. Therefore, we examined the association between adherence to the EAT-Lancet diet and cognitive ageing. METHODS: We used data from a previous intervention study involving cognitively healthy community-dwelling adults aged ≥65 years. Adherence to the EAT-Lancet diet was calculated using a recently published index and a 190-item food frequency questionnaire. Global and domain-specific cognitive functioning were assessed at baseline and after 2 years using a neuropsychological test battery. Multivariate-adjusted linear regression was conducted to examine associations between EAT-Lancet diet adherence and cognitive functioning (n = 630) and 2-year change (n = 302). RESULTS: Greater adherence to the EAT-Lancet diet was associated with better global cognitive functioning (ß per SD = 3.7 points [95% CI]: 0.04 [0.00, 0.08]) and slower rate of decline (ß per SD [95% CI]: 0.05 [0.02, 0.08]). With respect to domain-specific functioning, beneficial associations were observed cross-sectionally for executive functioning (P < 0.01), and longitudinally for change in executive functioning (P < 0.01) and attention and working memory (P < 0.01). The degree of adherence to the EAT-Lancet was not associated with (changes in) information processing speed or episodic memory. CONCLUSION: We demonstrated that greater adherence to the EAT-Lancet diet is associated with better global cognitive functioning and slower cognitive decline among cognitively healthy older adults. Further research is needed to confirm these findings and assess the potential benefits of the EAT-Lancet diet for the ageing population in a broader context.

Concurrent nutrient deficiencies are associated with dementia incidence.

INTRODUCTION: While observational research suggests a protective role for nutrition in brain aging, intervention studies remain inconclusive. This failing translation from observational to interventional research may result from overlooking nutrient interactions. METHODS: We developed a nutrient status index capturing the number of suboptimal statuses of omega-3 fatty acids, homocysteine, and vitamin D (range 0 to 3). We associated this index with dementia incidence in a subsample (age ≥ 50 years) of the Framingham Heart Study Offspring cohort. RESULTS: Among 968 participants, 79 developed dementia over 15.5 years (median follow-up). Each point increase in nutrient status index was associated with a 50% higher risk of dementia (hazard ratio [HR] = 1.50; 95% confidence interval [CI] = 1.16, 1.96). Participants with three high-risk statuses had a four-fold increased risk of dementia compared to participants without high-risk status (HR = 4.68; 95% CI = 1.69, 12.94). DISCUSSION: Concurrent nutrient deficiencies are associated with the risk of dementia. The potential of optimizing nutritional status to lower dementia risk warrants further study. HIGHLIGHTS: Nutrition and dementia research calls for multiple-nutrient approaches. We studied combined suboptimal statuses of omega-3 polyunsaturated fatty acids, homocysteine, and vitamin D. Suboptimal status of the three nutrients was associated with dementia risk. The risk estimate was larger than for other factors (ie, diabetes, apolipoprotein E Îµ4 carrier). Future studies should assess the effect of improving nutrient status on dementia risk.

Association between Low Vitamin D Status, Serotonin, and Clinico-Biobehavioral Parameters in Alzheimer's Disease.

INTRODUCTION: Studies suggest a role of vitamin D in the progression and symptomatology of Alzheimer's disease (AD), with few in vitro studies pointing to effects on serotonergic and amyloidogenic turnover. However, limited data exist in AD patients on the potential association with cognition and behavioral and psychological signs and symptoms of dementia (BPSD). In this retrospective cross-sectional study, we, therefore, explored potential correlations of serum 25-hydroxyvitamin D3 (25(OH)D3) concentrations, indicative of vitamin D status, with serum serotonin (5-hydroxytryptamine, 5-HT) levels, cognitive/BPSD scorings, and cerebrospinal fluid (CSF) biomarker levels. METHODS: Frozen serum samples of 25 well-characterized AD subjects as part of a previous BPSD cohort were analyzed, of which 15 had a neuropathologically confirmed diagnosis. Serum 25(OH)D3 levels were analyzed by means of LC-MS/MS, whereas 5-HT concentrations were quantified by competitive ELISA. RESULTS: Among AD patients, vitamin D deficiency was highly prevalent, defined as levels below 50 nmol/L. Regression analyses, adjusted for age, gender, and psychotropic medications, revealed that serum 25(OH)D3 and 5-HT levels were positively associated (p = 0.012). Furthermore, serum 25(OH)D3 concentrations correlated inversely with CSF amyloid-beta (Aß1-42) levels (p = 0.006), and serum 5-HT levels correlated positively with aggressiveness (p = 0.001), frontal behavior (p = 0.001), depression (p = 0.004), and partly with cognitive performance (p < 0.005). Lastly, AD patients on cholinesterase inhibitors had higher serum 25(OH)D3 (p = 0.030) and lower serum 5-HT (p = 0.012) levels. CONCLUSIONS: The molecular associations between low vitamin D status, serum 5-HT, and CSF Aß1-42 levels are highly remarkable, warranting further mechanistic and intervention studies to disclose potential involvement in the clinico-biobehavioral pathophysiology of AD.

The association between adherence to a plant-based diet and cognitive ageing.

PURPOSE: While the benefits of adopting a more plant-based diet for sustainability and animal welfare are clear, its long-term health impacts, including the impact on cognitive ageing, are limited studied. Therefore, we investigated the associations between plant-based diet adherence and cognitive ageing. METHODS: Data from a previous intervention study involving community-dwelling adults aged ≥ 65 years were analysed at baseline (n = 658) and after 2-year follow-up (n = 314). Global and domain-specific cognitive functioning were assessed at both timepoints. Overall, healthful and unhealthful plant-based dietary indices were calculated from a 190-item food frequency questionnaire. Multivariate-adjusted linear regression models were applied to test for associations. RESULTS: After full-adjustment, higher overall adherence to a plant-based diet was not associated with global cognitive function (difference in Z-score, tertile 1 versus 3 [95% CI]: 0.04 [- 0.05, 0.13] p = 0.40) or cognitive change (- 0.04 [- 0.11, 0.04], p = 0.35). Similarly, healthful and unhealthful plant-based diet indices were not associated with cognitive functioning (respectively p = 0.48; p = 0.87) or change (respectively p = 0.21, p = 0.33). Interestingly, we observed fish consumption to influence the association between plant-based diet adherence and cognitive functioning (p-interaction = 0.01), with only individuals with a fish consumption of ≥ 0.93 portion/week benefitting from better overall plant-based diet adherence (ß per 10-point increment [95% CI]: 0.12 [0.03, 0.21] p = 0.01). CONCLUSION: We did not demonstrate associations of a more plant-based diet with cognitive ageing. However, possibly such association exists in a subpopulation with higher fish intake. This would be in line with earlier observations that diets rich in plant foods and fish, such as the Mediterranean diet, may be beneficial for cognitive ageing. TRIAL REGISTRATION: Registered at clinicaltrials.gov (NCT00696514) on June 12, 2008.

DHA status influences effects of B-vitamin supplementation on cognitive ageing: a post-hoc analysis of the B-proof trial.

PURPOSE: Trials aiming to lower homocysteine by B-vitamin supplementation have reported mixed results on slowing cognitive decline. We investigated if efficacy of B-vitamin supplementation is affected by baseline plasma omega-3 fatty acid levels. METHODS: This post-hoc analysis of the B-proof trial included 191 adults aged 65 years or older with baseline plasma total homocysteine ≥ 12 µmol/L, randomly assigned to 400 µg folic acid and 500 µg vitamin B12 or placebo daily for 2 years. Global and domain-specific cognitive functioning were assessed at baseline and after 2 years. The effect of B-vitamin supplementation was analyzed according to tertiles of baseline plasma omega-3 fatty acids concentrations combined, and eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) individually using multiple linear regression analyses. RESULTS: The mean ± SD age of the participants was 71.6 ± 5.9 years and median [IQR] Mini-Mental State Examination was 29 [28-30]. The treatment effect of B-vitamins on global cognition was larger in participants in the high compared to the middle DHA tertile (difference in z-score, mean ± SE 0.22 ± 0.10, p = 0.03). There was no significant interaction between B-vitamin supplementation and combined omega-3 fatty acid (p = 0.49) and EPA (p = 0.99) tertiles. Similarly, the efficacy of B-vitamin treatment on domain-specific cognitive functioning did not link to omega-3 fatty acid, DHA, or EPA plasma levels. CONCLUSION: This post-hoc analysis indicated that efficacy of B-vitamin supplementation in slowing cognitive decline relates to DHA status, with individuals with higher plasma DHA levels benefitting more from vitamin B12 and folic acid use. The results support earlier observations that positive effects of B-vitamins in cognitive ageing may be subgroup-specific. TRIAL REGISTRATION: Registered at clinicaltrials.gov (NCT00696514) on June 12, 2008.

The Effect of Calcium Buffering and Calcium Sensor Type on the Sensitivity of an Array-Based Bitter Receptor Screening Assay.

The genetically encoded calcium sensor protein Cameleon YC3.6 has previously been applied for functional G protein-coupled receptor screening using receptor cell arrays. However, different types of sensors are available, with a wide range in [Ca2+] sensitivity, Hill coefficients, calcium binding domains, and fluorophores, which could potentially improve the performance of the assay. Here, we compared the responses of 3 structurally different calcium sensor proteins (Cameleon YC3.6, Nano140, and Twitch2B) simultaneously, on a single chip, at different cytosolic expression levels and in combination with 2 different bitter receptors, TAS2R8 and TAS2R14. Sensor concentrations were modified by varying the amount of calcium sensor DNA that was printed on the DNA arrays prior to reverse transfection. We found that ~2-fold lower concentrations of calcium sensor protein, by transfecting 4 times less sensor-coding DNA, resulted in more sensitive bitter responses. The best results were obtained with Twitch2B, where, relative to YC3.6 at the default DNA concentration, a 4-fold lower DNA concentration increased sensitivity 60-fold and signal strength 5- to 10-fold. Next, we compared the performance of YC3.6 and Twitch2B against an array with 11 different bitter taste receptors. We observed a 2- to 8-fold increase in sensitivity using Twitch2B compared with YC3.6. The bitter receptor arrays contained 300 spots and could be exposed to a series of 18 injections within 1 h resulting in 5400 measurements. These optimized sensor conditions provide a basis for enhancing receptomics calcium assays for receptors with poor Ca2+ signaling and will benefit future high-throughput receptomics experiments.

A Diet Rich in Fish Oil and Leucine Ameliorates Hypercalcemia in Tumour-Induced Cachectic Mice.

BACKGROUND: Dietary supplementation with leucine and fish oil rich in omega-3 fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) has previously been shown to reduce cachexia-related outcomes in C26 tumour-bearing mice. To further explore associated processes and mechanisms we investigated changes in plasma Ca2+ levels, the involvement of parathyroid hormone related protein (PTHrP), and its possible interactions with cyclooxygenase 2 (COX-2). METHODS: CD2F1 mice were subcutaneously inoculated with C26 adenocarcinoma cells or sham treated and divided in: (1) controls, (2) tumour-bearing controls, and (3) tumour-bearing receiving experimental diets. After 20 days, body and organ masses and total plasma Ca2+ levels were determined. Furthermore, effects of DHA, EPA and leucine on production of PTHrP were studied in cultured C26 cells. RESULTS: The combination of leucine and fish oil reduced tumour-associated hypercalcemia. Plasma Ca2+ levels negatively correlated with carcass mass and multiple organ masses. DHA was able to reduce PTHrP production by C26 cells in vitro. Results indicate that this effect occurred independently of COX-2 inhibition. CONCLUSION: Our results suggest that cancer-related hypercalcemia may be ameliorated by a nutritional intervention rich in leucine and fish oil. The effect of fish oil possibly relates to a DHA-induced reduction of PTHrP excretion by the tumour.

Increasing quality of life in pulmonary arterial hypertension: is there a role for nutrition?

Pulmonary arterial hypertension (PAH) is a progressive disease primarily affecting the pulmonary vasculature and heart. PAH patients suffer from exercise intolerance and fatigue, negatively affecting their quality of life. This review summarizes current insights in the pathophysiological mechanisms underlying PAH. It zooms in on the potential involvement of nutritional status and micronutrient deficiencies on PAH exercise intolerance and fatigue, also summarizing the potential benefits of exercise and nutritional interventions. Pubmed/Medline, Scopus, and Web of Science were searched for publications on pathophysiological mechanisms of PAH negatively affecting physical activity potential and nutritional status, and for potential effects of interventions involving exercise or nutritional measures known to improve exercise intolerance. Pathophysiological processes that contribute to exercise intolerance and impaired quality of life of PAH patients include right ventricular dysfunction, inflammation, skeletal muscle alterations, and dysfunctional energy metabolism. PAH-related nutritional deficiencies and metabolic alterations have been linked to fatigue, exercise intolerance, and endothelial dysfunction. Available evidence suggests that exercise interventions can be effective in PAH patients to improve exercise tolerance and decrease fatigue. By contrast, knowledge on the prevalence of micronutrient deficiencies and the possible effects of nutritional interventions in PAH patients is limited. Although data on nutritional status and micronutrient deficiencies in PAH are scarce, the available knowledge, including that from adjacent fields, suggests that nutritional intervention to correct deficiencies and metabolic alterations may contribute to a reduction of disease burden.

Calcium Imaging of GPCR Activation Using Arrays of Reverse Transfected HEK293 Cells in a Microfluidic System.

Reverse-transfected cell arrays in microfluidic systems have great potential to perform large-scale parallel screening of G protein-coupled receptor (GPCR) activation. Here, we report the preparation of a novel platform using reverse transfection of HEK293 cells, imaging by stereo-fluorescence microscopy in a flowcell format, real-time monitoring of cytosolic calcium ion fluctuations using the fluorescent protein Cameleon and analysis of GPCR responses to sequential sample exposures. To determine the relationship between DNA concentration and gene expression, we analyzed cell arrays made with variable concentrations of plasmid DNA encoding fluorescent proteins and the Neurokinin 1 (NK1) receptor. We observed pronounced effects on gene expression of both the specific and total DNA concentration. Reverse transfected spots with NK1 plasmid DNA at 1% of total DNA still resulted in detectable NK1 activation when exposed to its ligand. By varying the GPCR DNA concentration in reverse transfection, the sensitivity and robustness of the receptor response for sequential sample exposures was optimized. An injection series is shown for an array containing the NK1 receptor, bitter receptor TAS2R8 and controls. Both receptors were exposed 14 times to alternating samples of two ligands. Specific responses remained reproducible. This platform introduces new opportunities for high throughput screening of GPCR libraries.

Docosahexaenoyl serotonin emerges as most potent inhibitor of IL-17 and CCL-20 released by blood mononuclear cells from a series of N-acyl serotonins identified in human intestinal tissue.

Fatty acid amides (FAAs), conjugates of fatty acids with ethanolamine, mono-amine neurotransmitters or amino acids are a class of molecules that display diverse functional roles in different cells and tissues. Recently we reported that one of the serotonin-fatty acid conjugates, docosahexaenoyl serotonin (DHA-5-HT), previously found in gut tissue of mouse and pig, attenuates the IL-23-IL-17 signaling axis in LPS-stimulated mice macrophages. However, its presence and effects in humans remained to be elucidated. Here, we report for the first time its identification in human intestinal (colon) tissue, along with a series of related N-acyl serotonins. Furthermore, we tested these fatty acid conjugates for their ability to inhibit the release of IL-17 and CCL-20 by stimulated human peripheral blood mononuclear cells (PBMCs). Serotonin conjugates with palmitic acid (PA-5-HT), stearic acid (SA-5-HT) and oleic acid (OA-5-HT) were detected in higher levels than arachidonoyl serotonin (AA-5-HT) and DHA-5-HT, while eicosapentaenoyl serotonin (EPA-5-HT) could not be quantified. Among these, DHA-5-HT was the most potent in inhibiting IL-17 and CCL-20, typical Th17 pro-inflammatory mediators, by Concanavalin A (ConA)-stimulated human PBMCs. These results underline the idea that DHA-5-HT is a gut-specific endogenously produced mediator with the capacity to modulate the IL-17/Th17 signaling response. Our findings may be of relevance in relation to intestinal inflammatory diseases like Crohn's disease and Ulcerative colitis.

The role of hypothalamic inflammation, the hypothalamic-pituitary-adrenal axis and serotonin in the cancer anorexia-cachexia syndrome.

PURPOSE OF REVIEW: In cancer patients, the development of cachexia (muscle wasting) is frequently aggravated by anorexia (loss of appetite). Their concurrence is often referred to as anorexia-cachexia syndrome. This review focusses on the recent evidence underlining hypothalamic inflammation as key driver of these processes. Special attention is given to the involvement of hypothalamic serotonin. RECENT FINDINGS: The anorexia-cachexia syndrome is directly associated with higher mortality in cancer patients. Recent reports confirm its severe impact on the quality of life of patients and their families.Hypothalamic inflammation has been shown to contribute to muscle and adipose tissue loss in cancer via central hypothalamic interleukine (IL)1ß-induced activation of the hypothalamic-pituitary-adrenal axis. The resulting release of glucocorticoids directly stimulates catabolic processes in these tissues via activation of the ubiquitin-proteosome pathway. Next to this, hypothalamic inflammation has been shown to reduce food intake in cancer by triggering changes in orexigenic and anorexigenic responses via upregulation of serotonin availability and stimulation of its signalling pathways in hypothalamic tissues. This combination of reduced food intake and stimulation of tissue catabolism represents a dual mechanism by which hypothalamic inflammation contributes to the development and maintenance of anorexia and cachexia in cancer. SUMMARY: Hypothalamic inflammation is a driving force in the development of the anorexia-cachexia syndrome via hypothalamic-pituitary-adrenal axis and serotonin pathway activation.

Adaptation of exercise-induced stress in well-trained healthy young men.

NEW FINDINGS: What is the central question of this study? Exercise is known to induce stress-related physiological responses, such as changes in intestinal barrier function. Our aim was to determine the test-retest repeatability of these responses in well-trained individuals. What is the main finding and its importance? Responses to strenuous exercise, as indicated by stress-related markers such as intestinal integrity markers and myokines, showed high test-retest variation. Even in well-trained young men an adapted response is seen after a single repetition after 1 week. This finding has implications for the design of studies aimed at evaluating physiological responses to exercise. Strenuous exercise induces different stress-related physiological changes, potentially including changes in intestinal barrier function. In the Protégé Study (ISRCTN14236739; www.isrctn.com), we determined the test-retest repeatability in responses to exercise in well-trained individuals. Eleven well-trained men (27 ± 4 years old) completed an exercise protocol that consisted of intensive cycling intervals, followed by an overnight fast and an additional 90 min cycling phase at 50% of maximal workload the next morning. The day before (rest), and immediately after the exercise protocol (exercise) a lactulose and rhamnose solution was ingested. Markers of energy metabolism, lactulose-to-rhamnose ratio, several cytokines and potential stress-related markers were measured at rest and during exercise. In addition, untargeted urine metabolite profiles were obtained. The complete procedure (Test) was repeated 1 week later (Retest) to assess repeatability. Metabolic effect parameters with regard to energy metabolism and urine metabolomics were similar for both the Test and Retest period, underlining comparable exercise load. Following exercise, intestinal permeability (1 h plasma lactulose-to-rhamnose ratio) and the serum interleukin-6, interleukin-10, fibroblast growth factor-21 and muscle creatine kinase concentrations were significantly increased compared with rest only during the first test and not when the test was repeated. Responses to strenuous exercise in well-trained young men, as indicated by intestinal markers and myokines, show adaptation in Test-Retest outcome. This might be attributable to a carry-over effect of the defense mechanisms triggered during the Test. This finding has implications for the design of studies aimed at evaluating physiological responses to exercise.

Beta-blocker use and fall risk in older individuals: Original results from two studies with meta-analysis.

AIMS: To investigate the association between use of ß-blockers and ß-blocker characteristics - selectivity, lipid solubility, intrinsic sympathetic activity (ISA) and CYP2D6 enzyme metabolism - and fall risk. METHODS: Data from two prospective studies were used, including community-dwelling individuals, n = 7662 (the Rotterdam Study) and 2407 (B-PROOF), all aged ≥55 years. Fall incidents were recorded prospectively. Time-varying ß-blocker use was determined using pharmacy dispensing records. Cox proportional hazard models adjusted for age and sex were applied to determine the association between ß-blocker use, their characteristics - selectivity, lipid solubility, ISA and CYP2D6 enzyme metabolism - and fall risk. The results of the studies were combined using meta-analyses. RESULTS: In total 2917 participants encountered a fall during a total follow-up time of 89 529 years. Meta-analysis indicated no association between use of any ß-blocker, compared to nonuse, and fall risk, hazard ratio (HR) = 0.97 [95% confidence interval (CI) 0.88-1.06]. Use of a selective ß-blocker was also not associated with fall risk, HR = 0.92 (95%CI 0.83-1.01). Use of a nonselective ß-blocker was associated with an increased fall risk, HR = 1.22 (95%CI 1.01-1.48). Other ß-blocker characteristics including lipid solubility and CYP2D6 enzyme metabolism were not associated with fall risk. CONCLUSION: Our study suggests that use of a nonselective ß-blocker, contrary to selective ß-blockers, is associated with an increased fall risk in an older population. In clinical practice, ß-blockers have been shown effective for a variety of cardiovascular indications. However, fall risk should be considered when prescribing a ß-blocker in this age group, and the pros and cons for ß-blocker classes should be taken into consideration.

Public health relevance of drug-nutrition interactions.

The public health relevance of drug-nutrition interactions is currently highly undervalued and overlooked. This is particularly the case for elderly persons where multi-morbidity and consequently polypharmacy is very common. Vitamins and other micronutrients have central functions in metabolism, and their interactions with drugs may result in clinically relevant physiological impairments but possibly also in positive effects. On 12 April 2016, the University Medical Center Groningen (The Netherlands), as part of its Healthy Ageing program, organized a workshop on the public health relevance of drug-nutrient interactions. In this meeting, experts in the field presented results from recent studies on interactions between pharmaceuticals and nutrients, and discussed the role of nutrition for elderly, focusing on those persons receiving pharmaceutical treatment. This paper summarizes the proceedings of the symposium and provides an outlook for future research needs and public health measures. Since food, pharma and health are closely interconnected domains, awareness is needed in the medical community about the potential relevance of drug-nutrition interactions. Experts and stakeholders should advocate for the integration of drug-nutrition evaluations in the drug development process. Strategies for the individual patients should be developed, by installing drug review protocols, screening for malnutrition and integrating this topic into the general medical advice.

Decrease in Ionized and Total Magnesium Blood Concentrations in Endurance Athletes Following an Exercise Bout Restores within Hours-Potential Consequences for Monitoring and Supplementation.

Magnesium is essential for optimal sport performance, generating an interest to monitor its status in athletes. However, before measuring magnesium status in blood could become routine, more insight into its diurnal fluctuations and effects of exercise itself is necessary. Therefore, we measured the effect of an acute bout of exercise on ionized (iMg) and total plasma magnesium (tMg) in blood obtained from 18 healthy well-trained endurance athletes (age, 31.1 ± 8.1 yr.; VO2max, 50.9 ± 7.5 ml/kg/min) at multiple time points, and compared this with a resting situation. At both days, 7 blood samples were taken at set time points (8:30 fasted, 11:00, 12:30, 13:30, 15:00, 16:00, 18:30). The control day was included to correct for a putative diurnal fluctuation of magnesium. During the exercise day, athletes performed a 90 min bicycle ergometer test (70% VO2max) between 11:00 and 12:30. Whole blood samples were analyzed for iMg and plasma for tMg concentrations. Both concentrations decreased significantly after exercise (0.52 ± 0.04-0.45 ± 0.03 mmol/L and 0.81 ± 0.07-0.73 ± 0.06 mmol/L, respectively, p < .001) while no significant decline was observed during that time-interval on control days. Both, iMg and tMg, returned to baseline, on average, 2.5 hr after exercise. These findings suggest that timing of blood sampling to analyze Mg status is important. Additional research is needed to establish the recovery time after different types of exercise to come to a general advice regarding the timing of magnesium status assessment in practice.

Nutritional Supplement Use by Dutch Elite and Sub-Elite Athletes: Does Receiving Dietary Counseling Make a Difference?

The use of nutritional supplements is highly prevalent among athletes. In this cross-sectional study, we assessed the prevalence of nutritional supplement use by a large group of Dutch competitive athletes in relation to dietary counseling. A total of 778 athletes (407 males and 371 females) completed a web-based questionnaire about the use of nutritional supplements. Log-binomial regression models were applied to estimate crude and adjusted prevalence ratios (PR) for the use of individual nutritional supplements in athletes receiving dietary counseling as compared with athletes not receiving dietary counseling. Of the athletes, 97.2% had used nutritional supplements at some time during their sports career, whereas 84.7% indicated having used supplements during the last 4 weeks. The top ranked supplements used over the last 4 weeks from dietary supplements, sport nutrition products and ergogenic supplements were multivitamin and mineral preparations (42.9%), isotonic sports drinks (44.1%) and caffeine (13.0%). After adjustment for elite status, age, and weekly exercise duration, dietary counseling was associated with a higher prevalence of the use of vitamin D, recovery drinks, energy bars, isotonic drinks with protein, dextrose, beta-alanine, and sodium bicarbonate. In contrast, dietary counseling was inversely associated with the use of combivitamins, calcium, vitamin E, vitamin B2, retinol, energy drinks and BCAA and other amino acids. In conclusion, almost all athletes had used nutritional supplements at some time during their athletic career. Receiving dietary counseling seemed to result in better-informed choices with respect to the use of nutritional supplements related to performance, recovery, and health.

The Noncaloric Sweetener Rebaudioside A Stimulates Glucagon-Like Peptide 1 Release and Increases Enteroendocrine Cell Numbers in 2-Dimensional Mouse Organoids Derived from Different Locations of the Intestine.

BACKGROUND: Glucagon-like peptide 1 (GLP-1) contributes to satiety and plays a pivotal role in insulin secretion and glucose homeostasis. Similar to GLP-1, peptide YY (PYY) and cholecystokinin also influence food intake. The secretion of these hormones by enteroendocrine cells along the intestine is modulated by nutrients. Preparations from the Stevia rebaudiana plant, including rebaudioside A, are increasingly being used as noncaloric sweeteners. OBJECTIVE: We investigated the effects of rebaudioside A on enteroendocrine cells by assessing both cell numbers as well as their secretory capacity in an organoid model. METHODS: A 2-dimensional organoid model derived from duodenal, jejunal, and ileal crypts of a C57BL/6J mouse was developed and characterized with the use of gene expression and immunofluorescence. We stimulated these organoids with 10 mmol/L rebaudioside A for 1 h and measured their GLP-1, PYY, and cholecystokinin release. We also analyzed the effects of rebaudioside A on gene expression in enteroendocrine cells after an 18-h incubation. RESULTS: The 2-dimensional organoids contained crypt cells and differentiated villus cells, including enterocytes and goblet and enteroendocrine cells. These enteroendocrine cells stained positive for GLP-1, PYY, and serotonin. The cultured 2-dimensional organoids maintained their location-specific gene expression patterns. Compared with the control, rebaudioside A induced GLP-1 secretion 1.7-fold in the duodenum (P < 0.01), 2.2-fold in the jejunum (P < 0.01), and 4.3-fold in the ileum (P < 0.001). PYY release was increased by rebaudioside A 3-fold in the ileum compared with the control (P < 0.05). Long-term (18-h) stimulation with the sweetener induced the expression of the enteroendocrine-specific markers chromogranin A, glucagon, Pyy, and cholecystokinin 3.5- (P < 0.001), 3.5- (P < 0.001), 3.8- (P < 0.05), and 6.5-fold (P < 0.001), respectively. CONCLUSIONS: These results show novel ex vivo effects of rebaudioside A on enteroendocrine cells of the mouse small intestine and highlight potentially new applications for rebaudioside A in metabolic diseases.

Moderate alcohol consumption stimulates food intake and food reward of savoury foods.

The aim of this study was to investigate whether food reward plays a role in the stimulating effect of moderate alcohol consumption on subsequent food intake. In addition, we explored the role of oral and gut sensory pathways in alcohol's effect on food reward by modified sham feeding (MSF) or consumption of a preload after alcohol intake.In a single-blind crossover design, 24 healthy men were randomly assigned to either consumption of vodka/orange juice (20 g alcohol) or orange juice only, followed by consumption of cake, MSF of cake or no cake. Food reward was evaluated by actual food intake measured by an ad libitum lunch 45 min after alcohol ingestion and by behavioural indices of wanting and liking of four food categories (high fat, low fat, sweet and savoury).Moderate alcohol consumption increased food intake during the ad libitum lunch by 11% (+338 kJ, P = 0.004). Alcohol specifically increased intake (+127 kJ, P <0.001) and explicit liking (P = 0.019) of high-fat savoury foods. Moreover, moderate alcohol consumption increased implicit wanting for savoury (P = 0.013) and decreased implicit wanting for sweet (P = 0.017) before the meal. Explicit wanting of low-fat savoury foods only was higher after alcohol followed by no cake as compared to after alcohol followed by cake MSF (P = 0.009), but not as compared to alcohol followed by cake consumption (P = 0.082). Both cake MSF and cake consumption had no overall effect on behavioural indices of food reward.To conclude, moderate alcohol consumption increased subsequent food intake, specifically of high-fat savoury foods. This effect was related to the higher food reward experienced for savoury foods. The importance of oral and gut sensory signalling in alcohol's effect on food reward remains largely unclear.