A polyphenol-rich green Mediterranean diet enhances epigenetic regulatory potential: the DIRECT PLUS randomized controlled trial.

BACKGROUND: The capacity of a polyphenol-enriched diet to modulate the epigenome in vivo is partly unknown. Given the beneficial metabolic effects of a Mediterranean (MED) diet enriched in polyphenols and reduced in red/processed meat (green-MED), as previously been proven by the 18-month DIRECT PLUS randomized controlled trial, we analyzed the effects of the green-MED diet on methylome and transcriptome levels to highlight molecular mechanisms underlying the observed metabolic improvements. METHODS: Our study included 260 participants (baseline BMI = 31.2 kg/m2, age = 5 years) of the DIRECT PLUS trial, initially randomized to one of the intervention arms: A. healthy dietary guidelines (HDG), B. MED (440 mg polyphenols additionally provided by walnuts), C. green-MED (1240 mg polyphenols additionally provided by walnuts, green tea, and Mankai: green duckweed shake). Blood methylome and transcriptome of all study subjects were analyzed at baseline and after completing the 18-month intervention using Illumina EPIC and RNA sequencing technologies. RESULTS: A total of 1573 differentially methylated regions (DMRs; false discovery rate (FDR) < 5 %) were found in the green-MED compared to the MED (177) and HDG (377) diet participants. This corresponded to 1753 differentially expressed genes (DEGs; FDR < 5 %) in the green-MED intervention compared to MED (7) and HDG (738). Consistently, the highest number (6 %) of epigenetic modulating genes was transcriptionally changed in subjects participating in the green-MED intervention. Weighted cluster network analysis relating transcriptional and phenotype changes among participants subjected to the green-MED intervention identified candidate genes associated with serum-folic acid change (all P < 1 × 10-3) and highlighted one module including the KIR3DS1 locus, being negatively associated with the polyphenol changes (e.g. P < 1 × 10-4), but positively associated with the MRI-assessed superficial subcutaneous adipose area-, weight- and waist circumference- 18-month change (all P < 0.05). Among others, this module included the DMR gene Cystathionine Beta-Synthase, playing a major role in homocysteine reduction. CONCLUSIONS: The green-MED high polyphenol diet, rich in green tea and Mankai, renders a high capacity to regulate an individual's epigenome. Our findings suggest epigenetic key drivers such as folate and green diet marker to mediate this capacity and indicate a direct effect of dietary polyphenols on the one­carbon metabolism.

The effect of high-polyphenol Mediterranean diet on visceral adiposity: the DIRECT PLUS randomized controlled trial.

BACKGROUND: Mediterranean (MED) diet is a rich source of polyphenols, which benefit adiposity by several mechanisms. We explored the effect of the green-MED diet, twice fortified in dietary polyphenols and lower in red/processed meat, on visceral adipose tissue (VAT). METHODS: In the 18-month Dietary Intervention Randomized Controlled Trial PoLyphenols UnproceSsed (DIRECT-PLUS) weight-loss trial, 294 participants were randomized to (A) healthy dietary guidelines (HDG), (B) MED, or (C) green-MED diets, all combined with physical activity. Both isocaloric MED groups consumed 28 g/day of walnuts (+ 440 mg/day polyphenols). The green-MED group further consumed green tea (3-4 cups/day) and Wolffia globosa (duckweed strain) plant green shake (100 g frozen cubes/day) (+ 800mg/day polyphenols) and reduced red meat intake. We used magnetic resonance imaging (MRI) to quantify the abdominal adipose tissues. RESULTS: Participants (age = 51 years; 88% men; body mass index = 31.2 kg/m2; 29% VAT) had an 89.8% retention rate and 79.3% completed eligible MRIs. While both MED diets reached similar moderate weight (MED: - 2.7%, green-MED: - 3.9%) and waist circumference (MED: - 4.7%, green-MED: - 5.7%) loss, the green-MED dieters doubled the VAT loss (HDG: - 4.2%, MED: - 6.0%, green-MED: - 14.1%; p < 0.05, independent of age, sex, waist circumference, or weight loss). Higher dietary consumption of green tea, walnuts, and Wolffia globosa; lower red meat intake; higher total plasma polyphenols (mainly hippuric acid), and elevated urine urolithin A polyphenol were significantly related to greater VAT loss (p < 0.05, multivariate models). CONCLUSIONS: A green-MED diet, enriched with plant-based polyphenols and lower in red/processed meat, may be a potent intervention to promote visceral adiposity regression. TRIAL REGISTRATION: ClinicalTrials.gov , NCT03020186.

Obesity Hinders the Protective Effect of Selenite Supplementation on Insulin Signaling.

The intake of high-fat diets (HFDs) containing large amounts of saturated long-chain fatty acids leads to obesity, oxidative stress, inflammation, and insulin resistance. The trace element selenium, as a crucial part of antioxidative selenoproteins, can protect against the development of diet-induced insulin resistance in white adipose tissue (WAT) by increasing glutathione peroxidase 3 (GPx3) and insulin receptor (IR) expression. Whether selenite (Se) can attenuate insulin resistance in established lipotoxic and obese conditions is unclear. We confirm that GPX3 mRNA expression in adipose tissue correlates with BMI in humans. Cultivating 3T3-L1 pre-adipocytes in palmitate-containing medium followed by Se treatment attenuates insulin resistance with enhanced GPx3 and IR expression and adipocyte differentiation. However, feeding obese mice a selenium-enriched high-fat diet (SRHFD) only resulted in a modest increase in overall selenoprotein gene expression in WAT in mice with unaltered body weight development, glucose tolerance, and insulin resistance. While Se supplementation improved adipocyte morphology, it did not alter WAT insulin sensitivity. However, mice fed a SRHFD exhibited increased insulin content in the pancreas. Overall, while selenite protects against palmitate-induced insulin resistance in vitro, obesity impedes the effect of selenite on insulin action and adipose tissue metabolism in vivo.

The effect of a high-polyphenol Mediterranean diet (Green-MED) combined with physical activity on age-related brain atrophy: the Dietary Intervention Randomized Controlled Trial Polyphenols Unprocessed Study (DIRECT PLUS).

BACKGROUND: The effect of diet on age-related brain atrophy is largely unproven. OBJECTIVES: We aimed to explore the effect of a Mediterranean diet (MED) higher in polyphenols and lower in red/processed meat (Green-MED diet) on age-related brain atrophy. METHODS: This 18-mo clinical trial longitudinally measured brain structure volumes by MRI using hippocampal occupancy score (HOC) and lateral ventricle volume (LVV) expansion score as neurodegeneration markers. Abdominally obese/dyslipidemic participants were randomly assigned to follow 1) healthy dietary guidelines (HDG), 2) MED, or 3) Green-MED diet. All subjects received free gym memberships and physical activity guidance. Both MED groups consumed 28 g walnuts/d (+440 mg/d polyphenols). The Green-MED group consumed green tea (3-4 cups/d) and Mankai (Wolffia-globosa strain, 100 g frozen cubes/d) green shake (+800 mg/d polyphenols). RESULTS: Among 284 participants (88% men; mean age: 51 y; BMI: 31.2 kg/m2; APOE-ε4 genotype = 15.7%), 224 (79%) completed the trial with eligible whole-brain MRIs. The pallidum (-4.2%), third ventricle (+3.9%), and LVV (+2.2%) disclosed the largest volume changes. Compared with younger participants, atrophy was accelerated among those ≥50 y old (HOC change: -1.0% ± 1.4% compared with -0.06% ± 1.1%; 95% CI: 0.6%, 1.3%; P < 0.001; LVV change: 3.2% ± 4.5% compared with 1.3% ± 4.1%; 95% CI: -3.1%, -0.8%; P = 0.001). In subjects ≥ 50 y old, HOC decline and LVV expansion were attenuated in both MED groups, with the best outcomes among Green-MED diet participants, as compared with HDG (HOC: -0.8% ± 1.6% compared with -1.3% ± 1.4%; 95% CI: -1.5%, -0.02%; P = 0.042; LVV: 2.3% ± 4.7% compared with 4.3% ± 4.5%; 95% CI: 0.3%, 5.2%; P = 0.021). Similar patterns were observed among younger subjects. Improved insulin sensitivity over the trial was the parameter most strongly associated with brain atrophy attenuation (P < 0.05). Greater Mankai, green tea, and walnut intake and less red and processed meat were significantly and independently associated with reduced HOC decline (P < 0.05). Elevated urinary concentrations of the polyphenols urolithin-A (r = 0.24; P = 0.013) and tyrosol (r = 0.26; P = 0.007) were significantly associated with lower HOC decline. CONCLUSIONS: A Green-MED (high-polyphenol) diet, rich in Mankai, green tea, and walnuts and low in red/processed meat, is potentially neuroprotective for age-related brain atrophy.This trial was registered at clinicaltrials.gov as NCT03020186.

Impairment of gut microbial biotin metabolism and host biotin status in severe obesity: effect of biotin and prebiotic supplementation on improved metabolism.

OBJECTIVES: Gut microbiota is a key component in obesity and type 2 diabetes, yet mechanisms and metabolites central to this interaction remain unclear. We examined the human gut microbiome's functional composition in healthy metabolic state and the most severe states of obesity and type 2 diabetes within the MetaCardis cohort. We focused on the role of B vitamins and B7/B8 biotin for regulation of host metabolic state, as these vitamins influence both microbial function and host metabolism and inflammation. DESIGN: We performed metagenomic analyses in 1545 subjects from the MetaCardis cohorts and different murine experiments, including germ-free and antibiotic treated animals, faecal microbiota transfer, bariatric surgery and supplementation with biotin and prebiotics in mice. RESULTS: Severe obesity is associated with an absolute deficiency in bacterial biotin producers and transporters, whose abundances correlate with host metabolic and inflammatory phenotypes. We found suboptimal circulating biotin levels in severe obesity and altered expression of biotin-associated genes in human adipose tissue. In mice, the absence or depletion of gut microbiota by antibiotics confirmed the microbial contribution to host biotin levels. Bariatric surgery, which improves metabolism and inflammation, associates with increased bacterial biotin producers and improved host systemic biotin in humans and mice. Finally, supplementing high-fat diet-fed mice with fructo-oligosaccharides and biotin improves not only the microbiome diversity, but also the potential of bacterial production of biotin and B vitamins, while limiting weight gain and glycaemic deterioration. CONCLUSION: Strategies combining biotin and prebiotic supplementation could help prevent the deterioration of metabolic states in severe obesity. TRIAL REGISTRATION NUMBER: NCT02059538.

Tart Cherry Juice and Seeds Affect Pro-Inflammatory Markers in Visceral Adipose Tissue of High-Fat Diet Obese Rats.

BACKGROUND: Tart cherries (Prunus cerasus L.) are a rich source of anthocyanins. They are phytochemical flavonoids found in red and blue fruits, and vegetables that can reduce hyperlipidemia. Visceral Adipose Tissue (VAT) has emerged as a major player in driving obesity-related inflammatory response. METHODS: This study has investigated the potential positive effects of tart cherries on rats with Diet-Induced Obesity (DIO). In particular, the inflammatory status in retroperitoneal (RPW) and perigonadal (PGW) adipose tissue were studied. Rats were fed ad libitum for 17 weeks with a hypercaloric diet with the supplementation of tart cherries seeds powder (DS) and seeds powder plus tart cherries juice containing 1mg of anthocyanins (DJS). In RPW and PGW, expression of CRP, IL-1 ß, TNF-α, CCL2 and CD36, were measured by qRT-PCR, Western blot and immunohistochemistry techniques. RESULTS: No differences in the weight of RPW and PGW animals were found between DS and DJS groups compared to DIO rats. However, an increase of inflammatory markers was observed in DIO group in comparison with control lean rats. A modulation of these markers was evident upon tart cherry supplementation. CONCLUSION: Study results suggest that tart cherry enriched-diet did not modify the accumulation of visceral fat, but it decreased inflammatory markers in both tissues. Therefore, this supplementation could be useful, in combination with healthy lifestyles, to modify adipose tissue cell metabolism limiting-obesity related organ damage.

Activation of Endogenous H2S Biosynthesis or Supplementation with Exogenous H2S Enhances Adipose Tissue Adipogenesis and Preserves Adipocyte Physiology in Humans.

Aims: To investigate the impact of exogenous hydrogen sulfide (H2S) and its endogenous biosynthesis on human adipocytes and adipose tissue in the context of obesity and insulin resistance. Results: Experiments in human adipose tissue explants and in isolated preadipocytes demonstrated that exogenous H2S or the activation of endogenous H2S biosynthesis resulted in increased adipogenesis, insulin action, sirtuin deacetylase, and PPARγ transcriptional activity, whereas chemical inhibition and gene knockdown of each enzyme generating H2S (CTH, CBS, MPST) led to altered adipocyte differentiation, cellular senescence, and increased inflammation. In agreement with these experimental data, visceral and subcutaneous adipose tissue expression of H2S-synthesising enzymes was significantly reduced in morbidly obese subjects in association with attenuated adipogenesis and increased markers of adipose tissue inflammation and senescence. Interestingly, weight-loss interventions (including bariatric surgery or diet/exercise) improved the expression of H2S biosynthesis-related genes. In human preadipocytes, the expression of CTH, CBS, and MPST genes and H2S production were dramatically increased during adipocyte differentiation. More importantly, the adipocyte proteome exhibiting persulfidation was characterized, disclosing that different proteins involved in fatty acid and lipid metabolism, the citrate cycle, insulin signaling, several adipokines, and PPAR, experienced the most dramatic persulfidation (85-98%). Innovation: No previous studies investigated the impact of H2S on human adipose tissue. This study suggests that the potentiation of adipose tissue H2S biosynthesis is a possible therapeutic approach to improve adipose tissue dysfunction in patients with obesity and insulin resistance. Conclusion: Altogether, these data supported the relevance of H2S biosynthesis in the modulation of human adipocyte physiology. Antioxid. Redox Signal. 35, 319-340.

Treatment-Induced Neuropathy in Diabetes (TIND)-Developing a Disease Model in Type 1 Diabetic Rats.

Treatment-induced neuropathy in diabetes (TIND) is defined by the occurrence of an acute neuropathy within 8 weeks of an abrupt decrease in glycated hemoglobin-A1c (HbA1c). The underlying pathogenic mechanisms are still incompletely understood with only one mouse model being explored to date. The aim of this study was to further explore the hypothesis that an abrupt insulin-induced fall in HbA1c may be the prime causal factor of developing TIND. BB/OKL (bio breeding/OKL, Ottawa Karlsburg Leipzig) diabetic rats were randomized in three groups, receiving insulin treatment by implanted subcutaneous osmotic insulin pumps for 3 months, as follows: Group one received 2 units per day; group two 1 unit per day: and group three 1 unit per day in the first month, followed by 2 units per day in the last two months. We serially examined blood glucose and HbA1c levels, motor- and sensory/mixed afferent conduction velocities (mNCV and csNCV) and peripheral nerve morphology, including intraepidermal nerve fiber density and numbers of Iba-1 (ionized calcium binding adaptor molecule 1) positive macrophages in the sciatic nerve. Only in BB/OKL rats of group three, with a rapid decrease in HbA1c of more than 2%, did we find a significant decrease in mNCV in sciatic nerves (81% of initial values) after three months of treatment as compared to those group three rats with a less marked decrease in HbA1c <2% (mNCV 106% of initial values, p ≤ 0.01). A similar trend was observed for sensory/mixed afferent nerve conduction velocities: csNCV were reduced in BB/OKL rats with a rapid decrease in HbA1c >2% (csNCV 90% of initial values), compared to those rats with a mild decrease <2% (csNCV 112% of initial values, p ≤ 0.01). Moreover, BB/OKL rats of group three with a decrease in HbA1c >2% showed significantly greater infiltration of macrophages by about 50% (p ≤ 0.01) and a decreased amount of calcitonin gene related peptide (CGRP) positive nerve fibers as compared to the animals with a milder decrease in HbA1c. We conclude that a mild acute neuropathy with inflammatory components was induced in BB/OKL rats as a consequence of an abrupt decrease in HbA1c caused by high-dose insulin treatment. This experimentally induced neuropathy shares some features with TIND in humans and may be further explored in studies into the pathogenesis and treatment of TIND.

Effect of green-Mediterranean diet on intrahepatic fat: the DIRECT PLUS randomised controlled trial.

OBJECTIVE: To examine the effectiveness of green-Mediterranean (MED) diet, further restricted in red/processed meat, and enriched with green plants and polyphenols on non-alcoholic fatty liver disease (NAFLD), reflected by intrahepatic fat (IHF) loss. DESIGN: For the DIRECT-PLUS 18-month randomized clinical trial, we assigned 294 participants with abdominal obesity/dyslipidaemia into healthy dietary guidelines (HDG), MED and green-MED weight-loss diet groups, all accompanied by physical activity. Both isocaloric MED groups consumed 28 g/day walnuts (+440 mg/day polyphenols provided). The green-MED group further consumed green tea (3-4 cups/day) and Mankai (a Wolffia globosa aquatic plant strain; 100 g/day frozen cubes) green shake (+1240 mg/day total polyphenols provided). IHF% 18-month changes were quantified continuously by proton magnetic resonance spectroscopy (MRS). RESULTS: Participants (age=51 years; 88% men; body mass index=31.3 kg/m2; median IHF%=6.6%; mean=10.2%; 62% with NAFLD) had 89.8% 18-month retention-rate, and 78% had eligible follow-up MRS. Overall, NAFLD prevalence declined to: 54.8% (HDG), 47.9% (MED) and 31.5% (green-MED), p=0.012 between groups. Despite similar moderate weight-loss in both MED groups, green-MED group achieved almost double IHF% loss (-38.9% proportionally), as compared with MED (-19.6% proportionally; p=0.035 weight loss adjusted) and HDG (-12.2% proportionally; p<0.001). After 18 months, both MED groups had significantly higher total plasma polyphenol levels versus HDG, with higher detection of Naringenin and 2-5-dihydroxybenzoic-acid in green-MED. Greater IHF% loss was independently associated with increased Mankai and walnuts intake, decreased red/processed meat consumption, improved serum folate and adipokines/lipids biomarkers, changes in microbiome composition (beta-diversity) and specific bacteria (p<0.05 for all). CONCLUSION: The new suggested strategy of green-Mediterranean diet, amplified with green plant-based proteins/polyphenols as Mankai, green tea, and walnuts, and restricted in red/processed meat can double IHF loss than other healthy nutritional strategies and reduce NAFLD in half. TRIAL REGISTRATION NUMBER: NCT03020186.

Effects of a blend of green tea and curcuma extract supplementation on lipopolysaccharide-induced inflammation in horses and ponies.

BACKGROUND: In horses and ponies numerous medical conditions are known to be linked with inflammation in different tissues, especially in the liver. Besides affecting other metabolic pathways such as the expression of certain interleukins (IL), inflammation is associated with stress of the endoplasmic reticulum (ER). In particular, ER stress leads to adaptive stress response and can be measured by several markers of inflammatory and stress signalling pathways, like nuclear factor κB (NF-kB). OBJECTIVES: To investigate lipopolysaccharide (LPS)-induced inflammatory reactions and their modulation in horses and ponies by feeding a polyphenol-rich supplement consisting of green tea and curcuma. METHODS: In a cross-over study, 11 animals were allocated to either a placebo or a supplement group and supplemented with 10 g of a blend of green tea and curcuma extract (GCE) or a placebo (calcium carbonate) once daily. After 21 days of supplementation, all animals underwent a LPS challenge to induce moderate systemic inflammation. Blood samples and liver biopsies were taken at standardized time points: 24 hours before and 12 hours after LPS challenge. Inflammatory blood parameters such as serum amyloid A (SAA), haptoglobin and retinol binding protein 4 (RBP4) were measured in serum. Hepatic mRNA levels of selected markers of inflammation such as haptoglobin, tumor necrosis factor α (TNF-α), IL-1ß, IL-6, cluster of differentiation 68 (CD68), fibroblast growth factor 21 (FGF-21), NF-κB, activating transcription factor 4 (ATF4) were quantified by RT-qPCR. In addition, liver biopsies were examined histologically for inflammatory alterations. RESULTS: Blood markers of acute inflammatory response increased after LPS challenge. In the liver, the proinflammatory cytokine IL-1ß showed significantly lower mRNA levels after LPS challenge in the supplemented group (P = 0.04) compared to the placebo group. Levels of the hepatic CD68 mRNA increased significantly in the placebo group (P = 0.04). There were no significant differences between supplemented and placebo groups concerning other markers of inflammation and markers of ER stress within the liver. The number of hepatic macrophages were not different after LPS challenge in both feeding groups. CONCLUSION: LPS was able to induce inflammation but seemed less suitable to induce ER stress in the horses and ponies. The polyphenol-rich supplement showed some potential to reduce inflammatory responses. Nevertheless, the supplementation did not exert an overall anti-inflammatory effect in horses and ponies.

The Effect of Wolffia globosa Mankai, a Green Aquatic Plant, on Postprandial Glycemic Response: A Randomized Crossover Controlled Trial.

OBJECTIVE: To compare the postprandial and overnight glycemic response using a novel green aquatic plant thought to provide a dietary source for high-quality protein, with an iso-carbohydrate/protein/caloric dairy shake. RESEARCH DESIGN AND METHODS: This is a randomized controlled crossover trial among 20 abdominally obese participants (age 51.4 years; fasting plasma glucose 110.9 mg/dL), who were allocated to replace dinner with either, first, a green shake containing Wolffia globosa duckweed (Mankai: specific-strain) or an iso-carbohydrate/protein/calorie yogurt shake. A 2-week flash glucose-monitoring system was used to assess postmeal glucose dynamics (6 net administration days; 97 observation days in total). We further obtained from each participant dietary/daily activity/satiety scale/sleep logs. Participants were recruited from the green-Mediterranean diet arm of the 18-month Dietary Intervention Randomized Controlled Trial-Polyphenols Unprocessed (DIRECT-PLUS) study. RESULTS: Wolffia globosa Mankai elicited a lower postprandial glucose peak compared with yogurt (∆peak = 13.4 ± 9.2 vs. 19.3 ± 15.1 mg/dL; P = 0.044), which occurred later (77.5 ± 29.2 vs. 59.2 ± 28.4 min; P = 0.037) and returned faster to baseline glucose levels (135.8 ± 53.1 vs. 197.5 ± 70.2 min; P = 0.012). The mean post-net incremental area under the curve (netAUC) was lower with Wolffia globosa up to 60 and 180 min (netAUC 60 min: 185.1 ± 340.1 vs. 441.4 ± 336.5 mg/dL/min, P = 0.005; netAUC 180 min: 707.9 ± 1,428.5 vs. 1,576.6 ± 1,810.1 mg/dL/min, P = 0.037). A Wolffia globosa-based shake replacing dinner resulted in lower next-morning fasting glucose levels (83.2 ± 0.8 vs. 86.6 ± 13 mg/dL; P = 0.041). Overall, postprandial glucose levels from the shake administration until the next morning were lower in the Wolffia globosa Mankai green shake compared with the yogurt shake (P < 0.001). Overnight sleep duration was similar (378.2 ± 22.4 vs. 375.9 ± 28.4 min; P = 0.72), and satiety rank was slightly higher for the Wolffia globosa shake compared with the yogurt shake (7.5 vs. 6.5; P = 0.035). CONCLUSIONS: Wolffia globosa Mankai duckweed may serve as an emerging alternative plant protein source with potential beneficial postprandial glycemic effects.

A Green-Mediterranean Diet, Supplemented with Mankai Duckweed, Preserves Iron-Homeostasis in Humans and Is Efficient in Reversal of Anemia in Rats.

BACKGROUND: Decreased dietary meat may deplete iron stores, as plant-derived iron bioavailability is typically limited. OBJECTIVES: We explored the effect of a low-meat Mediterranean (green-MED) diet, supplemented with Wolffia globosa duckweed (Mankai: rich in protein and iron) as a food source for humans, on iron status. We further examined the iron bioavailability of Mankai in rats. METHODS: Two hundred and ninety-four abdominally obese/dyslipidemic [mean age = 51.1 y; body mass index (kg/m2) = 31.3; 88% men] nonanemic participants were randomly assigned to physical activity (PA), PA + MED diet, or PA + green-MED diet. Both isocaloric MED groups consumed 28 g walnuts/d and the low-meat green-MED group further consumed green tea (800 mL/d) and Mankai (100 g green shake/d). In a complementary animal experiment, after 44 d of an iron deficiency anemia-inducing diet, 50 female rats (age = 3 wk; Sprague Dawley strain) were randomly assigned into: iron-deficient diet (vehicle), or vehicle + iso-iron: ferrous gluconate (FG) 14, Mankai 50, and Mankai 80 versions (1.7 mg · kg-1 · d-1 elemental iron), or FG9.5 and Mankai 50-C version (1.15 mg · kg-1 · d-1 elemental iron). The specific primary aim for both studies was changes in iron homeostasis parameters. RESULTS: After 6 mo of intervention, iron status trajectory did not differ between the PA and PA + MED groups. Hemoglobin modestly increased in the PA + green-MED group (0.23 g/dL) compared with PA (-0.1 g/dL; P < 0.001) and PA + MED (-0.1 g/dL; P < 0.001). Serum iron and serum transferrin saturation increased in the PA + green-MED group compared with the PA group (8.21 µg/dL compared with -5.23 µg/dL and 2.39% compared with -1.15%, respectively; P < 0.05 for both comparisons), as did folic acid (P = 0.011). In rats, hemoglobin decreased from 15.7 to 9.4 mg/dL after 44 d of diet-induced anemia. After depletion treatment, the vehicle-treated group had a further decrease of 1.3 mg/dL, whereas hemoglobin concentrations in both FG and Mankai iso-iron treatments similarly rebounded (FG14: +10.8 mg/dL, Mankai 50: +6.4 mg/dL, Mankai 80: +7.3 mg/dL; FG9.5: +5.1 mg/dL, Mankai 50-C: +7.1 mg/dL; P < 0.05 for all vs. the vehicle group). CONCLUSIONS: In humans, a green-MED low-meat diet does not impair iron homeostasis. In rats, iron derived from Mankai (a green-plant protein source) is bioavailable and efficient in reversal of anemia. This trial was registered at clinicaltrials.gov as NCT03020186.

The Role of Iron and Nerve Inflammation in Diabetes Mellitus Type 2-Induced Peripheral Neuropathy.

Peripheral diabetic neuropathy (PDN) is one of the most common complications of diabetes mellitus. Previous studies showed an association between dietary iron load and inflammation in the development of PDN in a rat model of type 1 diabetes (T1D). Here we investigated the role of iron and neural inflammation in development of PDN in a animal model of obesity and type 2 diabetes (T2D). 3-month-old db/db mice were fed with a high, standard or low iron diet for 4 months. High iron chow lead to a significant increase in motor nerve conduction velocities compared to mice on standard and low iron chow. Direct beneficiary effects on lowering blood glucose and HbA1c concentrations were shown in the high iron treated diabetic mice. Numbers of pro-inflammatory M1 macrophages were reduced in nerve sections, and anti-inflammatory M2 macrophages were increased in db/db mice on high iron diet compared to other groups. These results confirm and extend our previous findings in STZ-diabetic rats by showing that dietary non-hem iron supplementation may partly prevent the development of PDN in opposition to iron restriction. The identification of these dietary iron effects on the metabolic and inflammatory mechanisms of PDN supports a role of dietary iron and leads us to suggest testing for iron levels in human diabetic patients.

Genomic insights into the origin of farming in the ancient Near East.

We report genome-wide ancient DNA from 44 ancient Near Easterners ranging in time between ~12,000 and 1,400 bc, from Natufian hunter-gatherers to Bronze Age farmers. We show that the earliest populations of the Near East derived around half their ancestry from a 'Basal Eurasian' lineage that had little if any Neanderthal admixture and that separated from other non-African lineages before their separation from each other. The first farmers of the southern Levant (Israel and Jordan) and Zagros Mountains (Iran) were strongly genetically differentiated, and each descended from local hunter-gatherers. By the time of the Bronze Age, these two populations and Anatolian-related farmers had mixed with each other and with the hunter-gatherers of Europe to greatly reduce genetic differentiation. The impact of the Near Eastern farmers extended beyond the Near East: farmers related to those of Anatolia spread westward into Europe; farmers related to those of the Levant spread southward into East Africa; farmers related to those of Iran spread northward into the Eurasian steppe; and people related to both the early farmers of Iran and to the pastoralists of the Eurasian steppe spread eastward into South Asia.

Does vitamin D supplementation alter plasma adipokines concentrations? A systematic review and meta-analysis of randomized controlled trials.

We aimed to elucidate the role of vitamin D supplementation on adipokines through a systematic review and a meta-analysis of randomized placebo-controlled trials (RCTs). The search included PUBMED, Scopus, Web of Science and Google Scholar through July 1st, 2015. Finally we identified 9 RCTs and 484 participants. Meta-analysis of data from 7 studies did not find a significant change in plasma adiponectin concentrations following vitamin D supplementation (mean difference [MD]: 4.45%, 95%CI: -3.04, 11.93, p=0.244; Q=2.18, I(2)=0%). In meta-regression, changes in plasma adiponectin concentrations following vitamin D supplementation were found to be independent of treatment duration (slope: 0.25; 95%CI: -0.69, 1.19; p=0.603) and changes in serum 25-hydroxy vitamin D [25(OH)D] levels (slope: -0.02; 95%CI: -0.15, 0.12; p=0.780). Meta-analysis of data from 6 studies did not find a significant change in plasma leptin concentrations following vitamin D supplementation (MD: -4.51%, 95%CI: -25.13, 16.11, p=0.668; Q=6.41, I(2)=21.97%). Sensitivity analysis showed that this effect size is sensitive to one of the studies; removing it resulted in a significant reduction in plasma leptin levels (MD: -12.81%, 95%CI: -24.33, -1.30, p=0.029). In meta-regression, changes in plasma leptin concentrations following vitamin D supplementation were found to be independent of treatment duration (slope: -1.93; 95%CI: -4.08, 0.23; p=0.080). However, changes in serum 25(OH)D were found to be significantly associated with changes in plasma leptin levels following vitamin D supplementation (slope: 1.05; 95%CI: 0.08, 2.02; p=0.033). In conclusion, current data did not indicate a significant effect of vitamin D supplementation on adiponectin and leptin levels.

Benefits of foods supplemented with vegetable oils rich in α-linolenic, stearidonic or docosahexaenoic acid in hypertriglyceridemic subjects: a double-blind, randomized, controlled trail.

PURPOSE: The aim of the study was to investigate the influence of foods enriched with vegetable oils varying in their n-3 polyunsaturated fatty acids profile on cardiovascular risk factors for hypertriglyceridemic subjects. METHODS: Fifty-nine hypertriglyceridemic subjects (triglycerides ≥ 1.5 mmol/L) were included in the randomized, double-blind, placebo-controlled, crossover study. The placebo group received sunflower oil [linoleic acid (LA) group; 10 g LA/day]. The intervention groups received linseed oil [α-linolenic acid (ALA) group; 7 g ALA/day], echium oil [stearidonic acid (SDA) group; 2 g SDA/day] or microalgae oil [docosahexaenoic acid (DHA) group; 2 g DHA/day] over 10 weeks. Blood samples were collected at baseline and at the end of each period. RESULTS: Total cholesterol (TC) and low-density-lipoprotein cholesterol decreased significantly in the LA and ALA groups (LA: P ≤ 0.01, ALA: P ≤ 0.05). No changes in blood lipids were observed in the SDA group. Significant increases in TC and high-density-lipoprotein cholesterol occurred in the DHA group (P ≤ 0.05). In the ALA and SDA groups, the content of eicosapentaenoic acid in erythrocyte lipids increased significantly (P ≤ 0.05) after 10 weeks (ALA group: 38 ± 37 %, SDA group: 73  ± 59 %). CONCLUSION: Foods enriched with different vegetable oils rich in ALA or SDA are able to increase the n-3 long-chain polyunsaturated fatty acids content in erythrocyte lipids; echium oil is more potent in comparison with linseed oil. Blood lipids were beneficially modified through the consumption of food products enriched with sunflower, linseed and microalgae oils, whereas echium oil did not affect blood lipids. ClinicalTrials.gov: NCT01437930.

Serum vaspin concentrations are decreased after exercise-induced oxidative stress.

Elevated visceral adipose tissue-derived serpin (vaspin) serum concentrations are associated with impaired insulin sensitivity, but increase unexpectedly after long-term physical training. We therefore investigated the effect of an acute exercise bout and the effects of vitamin supplementation on chronic exercise effect and on serum vaspin concentrations. We measured serum vaspin and thiobarbituric acid-reactive substances (TBARS) concentrations in 80 individuals before and after a 1-hour acute exercise bout and independently in 40 healthy young men who were randomly assigned to either antioxidant (vitamin C (1,000 mg/day) and vitamin E (400 IU/day)) or to no supplementation after a standardized 4-week physical training program as a post hoc analysis. Serum vaspin concentrations significantly decreased after acute physical exercise as well as after 4 weeks of training in individuals without antioxidants. Changes in vaspin serum concentration correlate with increased TBARS serum concentrations both in response to a 1-hour exercise bout (r = -0.42, p < 0.01) and to the 4-week training (r = -0.31, p < 0.05). Interestingly, supplementation with antioxidants rather increased circulating vaspin levels in response to 4 weeks of exercise. In conclusion, vaspin serum concentrations are decreased by exercise-induced oxidative stress, but not by exercise-associated improvement in insulin sensitivity.

Antioxidants prevent health-promoting effects of physical exercise in humans.

Exercise promotes longevity and ameliorates type 2 diabetes mellitus and insulin resistance. However, exercise also increases mitochondrial formation of presumably harmful reactive oxygen species (ROS). Antioxidants are widely used as supplements but whether they affect the health-promoting effects of exercise is unknown. We evaluated the effects of a combination of vitamin C (1000 mg/day) and vitamin E (400 IU/day) on insulin sensitivity as measured by glucose infusion rates (GIR) during a hyperinsulinemic, euglycemic clamp in previously untrained (n = 19) and pretrained (n = 20) healthy young men. Before and after a 4 week intervention of physical exercise, GIR was determined, and muscle biopsies for gene expression analyses as well as plasma samples were obtained to compare changes over baseline and potential influences of vitamins on exercise effects. Exercise increased parameters of insulin sensitivity (GIR and plasma adiponectin) only in the absence of antioxidants in both previously untrained (P < 0.001) and pretrained (P < 0.001) individuals. This was paralleled by increased expression of ROS-sensitive transcriptional regulators of insulin sensitivity and ROS defense capacity, peroxisome-proliferator-activated receptor gamma (PPARgamma), and PPARgamma coactivators PGC1alpha and PGC1beta only in the absence of antioxidants (P < 0.001 for all). Molecular mediators of endogenous ROS defense (superoxide dismutases 1 and 2; glutathione peroxidase) were also induced by exercise, and this effect too was blocked by antioxidant supplementation. Consistent with the concept of mitohormesis, exercise-induced oxidative stress ameliorates insulin resistance and causes an adaptive response promoting endogenous antioxidant defense capacity. Supplementation with antioxidants may preclude these health-promoting effects of exercise in humans.