Acute Effects of Beetroot Juice Supplementation on Isometric Muscle Strength, Rate of Torque Development and Isometric Endurance in Young Adult Men and Women: A Randomized, Double-Blind, Controlled Cross-Over Pilot Study.

This study was conducted to investigate the effect of concentrated beetroot juice on isometric strength and knee extensor muscle endurance in healthy adults. We conducted a randomized cross-over, double-blind experiment in which participants (18 healthy, physically active adults, 9 men, 9 women) consumed either concentrated beetroot juice (140 mL) or low-nitrate control supplement 2.5 h before the measurement. Isometric maximum strength (peak torque), explosive strength (isometric rate of torque development), and strength endurance at 50% of peak torque were measured on an isometric dynamometer. The results showed that concentrated beetroot juice had no effect on the maximum voluntary isometric strength and rate of torque development of the knee extensors. The only exception was the maximum rate of torque development, for which a positive influence was demonstrated only in men. As for the endurance of the knee extensors, the supplement had a positive effect in men (endurance time increased from 86.4 ± 46.1 s to 103.4 ± 53.7 s; p = 0.022), but not in women. The absence of effect on maximal voluntary strength is consistent with previous research. One the other hand, improvements in endurance and rate of torque development in men only point to an important aspect of a previously under-researched area of sex-specific responses to nitrate supplementation.

A Comparative Study of the Antioxidative Effects of Helichrysum italicum and Helichrysum arenarium Infusions.

Helichrysum arenarium (L.) Moench (abbrev. as HA) has a long tradition in European ethnomedicine and its inflorescences are approved as a herbal medicinal product. In the Mediterranean part of Europe, Helichrysum italicum (Roth) G. Don (abbrev. as HI) is more common. Since infusions from both plants are traditionally used, we aimed to compare their antioxidative potential using in vitro assays. Two morphologically distinct HI plants, HIa and HIb, were compared to a commercially available HA product. Genetic analysis using microsatellites confirmed a clear differentiation between HI and HA and suggested that HIb was a hybrid resulting from spontaneous hybridization from unknown HI subspecies. High-performance liquid chromatography-mass spectrometry analysis showed the highest amounts of hydroxycinnamic acids and total arzanol derivatives in HIa, whereas HIb was richest in monohydroxybenzoic acids, caffeic acids, and coumarins, and HA contained the highest amounts of flavonoids, especially flavanones. HIa exhibited the highest radical scavenging activity; it was more efficient in protecting different cell lines from induced oxidative stress and in inducing oxidative stress-related genes superoxide dismutase 1, catalase, and glutathione reductase 1. The antioxidative potential of HI was not only dependent on the morphological type of the plant but also on the harvest date, revealing important information for obtaining the best possible product. Considering the superior properties of HI compared to HA, the evaluation of HI as a medicinal plant could be recommended.

HPLC-DAD-ESI-QTOF-MS Determination of Bioactive Compounds and Antioxidant Activity Comparison of the Hydroalcoholic and Water Extracts from Two Helichrysum italicum Species.

Mediterranean plant Helichrysum italicum represents a rich source of versatile bioactive compounds with potential benefits for human health. Despite extensive research on the plant's active constituents, little attention has yet been paid to characterizing the relationship between its intra-specific genetic diversity and metabolite profile. The study aimed to determine metabolic profile of H. italicum ssp. italicum (HII) and ssp. tyrrhenicum (HIT) cultivated on the experimental plantation in Slovenia and to compare the chemical composition of extracts regarding the solvent extraction process. Extracts were prepared upon conventional extract preparation procedures: maceration with 50 % methanol or ethanol and cold or hot water infusion and analyzed using High Performance Liquid Chromatography-Diode Array Detection-Electrospray Ionization-Quadrupole Time-of-Flight-Mass Spectrometry (HPLC-DAD-ESI-QTOF-MS). One hundred compounds were identified in the samples, among them several isomers and derivatives were reported for the first time, while caffeoylquinic acids and pyrones were the most abundant. Semi-quantitative comparison revealed that the extraction procedure had a greater impact on the chemical profile than genetic variability. All HIT extracts showed a higher total phenolic content compared to HII, while the antioxidant potential evaluated by 1,1-diphenyl-2-picrylhydrazil test was not proportionally higher. In addition, hot water extracts proved to be comparably active as alcoholic ones, confirming high commercial potential of Helichrysum italicum as herbal functional beverages.

Assessment of micronutrients in a 12-wk ketogenic diet in obese adults.

OBJECTIVE: A 12-wk ketogenic diet was found to have many beneficial effects in healthy obese adults, but it is not clear if the supply of micronutrients is adequate. METHODS: In 35 adult individuals with body mass index >30, the intakes of minerals and their serum levels were analyzed at baseline and at weeks 4 and 12 of the ketogenic diet intervention. The intake of vitamins and serum antioxidative potential were also investigated. RESULTS: Throughout the diet the intakes of magnesium, calcium, iron, phosphorus, and potassium were less than recommended values, but serum levels always remained within the reference range. Nevertheless, the level of calcium decreased significantly (from 2.52 ± 0.10 mmol/L at baseline to 2.36 ± 0.07 mmol/L at week 12, P < 0.001), which could be due to the omission of legumes and reduced dairy intake or because of the high fat intake alone. The levels of phosphate increased concomitantly. Calcium serum levels were negatively associated with ω-6 but not with ω-3 unsaturated fatty acid intake. The intakes of water-soluble vitamins were also too low. However, the antioxidative potential of serum did not change during intervention. CONCLUSIONS: Careful choice of foods that will provide the necessary micronutrients is of utmost importance when consuming ketogenic diet. In the 12 wk study the decreased intakes were not reflected in serum values, but special attention to calcium should be advised if such diet is recommended for longer periods.

Effects of Royal Jelly Administration on Lipid Profile, Satiety, Inflammation, and Antioxidant Capacity in Asymptomatic Overweight Adults.

OBJECTIVES: Obesity and overweight are chronic disorders of multifactorial origin that are characterized by high oxidative status and by chronic activation of macrophages in peripheral tissues. Effective therapeutic approaches to lower inflammation and oxidative stress are currently of general interest. Royal jelly (RJ) is a functional food with a broad range of pharmacological activities, mainly used by healthy individuals or borderline patients to protect themselves against disease onset. The objective of this randomized, double-blind, placebo-controlled trial was to investigate the effects of RJ supplementation on metabolic profile and oxidative and inflammatory parameters in asymptomatic overweight adults, considered at an early stage of developing metabolic syndrome. MATERIAL AND METHODS: The experimental group (n=30) was given RJ and the control group (n=30) was provided with a placebo for eight weeks. Anthropometric, biochemical parameters, biomarkers of oxidative stress, and inflammation were assessed at baseline, after 4 and 8 weeks of the intervention, and after additional 2 weeks of follow up. RESULTS AND CONCLUSION: Compared with the placebo, RJ supplementation demonstrated a statistically significant decrease in total cholesterol (6.7%; p=0.041) and inflammatory marker C-reactive protein (19%; p=0.027), whereas significant increases were observed in anti-inflammatory marker adiponectin (34%; p=0.011), endogenous antioxidants bilirubin (35%; p=0.002) and uric acid (5%; p=0.018), total antioxidant capacity in serum (54%; p=0.005), and leptin (17%; p=0.025). The present study demonstrated positive effects of RJ administration on lipid profile, satiety, inflammation, and antioxidant capacity in overweight adults. Therefore, our study supports the benefits of RJ supplementation for the improvement of human health.

Randomized controlled trial investigating the effects of a breastfeeding relaxation intervention on maternal psychological state, breast milk outcomes, and infant behavior and growth.

BACKGROUND: Biological signaling and communication between mothers and infants during breastfeeding may shape infant behavior and feeding. This signaling is complex and little explored in humans, although it is potentially relevant for initiatives to improve breastfeeding rates. OBJECTIVES: The aim of this study was to investigate physiological and psychological aspects of mother-infant signaling during breastfeeding experimentally, testing the effects of a relaxation intervention on maternal psychological state, breast milk intake, milk cortisol levels, and infant behavior and growth. METHODS: Primiparous breastfeeding mothers and full-term infants were randomly assigned to receive relaxation therapy [intervention relaxation group; n = 33 (RG)] or to the control group [n = 31 (CG); no relaxation therapy] at 2 wk postpartum. Both groups received standard breastfeeding support. Home visits were conducted at 2 (HV1), 6 (HV2), 12 (HV3) and 14 (HV4) wk to measure maternal stress and anxiety, breast milk intake and milk cortisol, and infant behavior and growth. RESULTS: RG mothers had lower stress scores postintervention than the CG (HV3 ∆ = -3.13; 95% CI: -5.9, -0.3) and lower hindmilk cortisol at HV1 (∆ = -44.5%; 95% CI: -76.1%, -12.9%) but not at HV2. RG infants had longer sleep duration (∆ = 82 min/d; 95% CI: 16, 149 min/d) at HV2 and higher gains in weight and body mass index standardized deviation score than the CG infants (∆ = 0.76; 95% CI: 0.3, 1.22; and ∆ = 0.59; 95% CI: 0.09, 1.1, respectively). RG infants had a mean milk intake at HV3 that was 227 g/d higher than that of the CG infants (P = 0.031) after controlling for gender and milk intake at HV1. CONCLUSIONS: The trial shows the effectiveness of a simple relaxation intervention for improving maternal and infant outcomes and identifies some potential signaling mechanisms for investigation in future and larger studies, especially in settings where mothers are more stressed, such as those with preterm or low birth weight infants. This trial was registered at clinicaltrials.gov as NCT01971216.

Roasting intensity of naturally low-caffeine Laurina coffee modulates glucose metabolism and redox balance in humans.

OBJECTIVE: Coffee consumption is negatively associated with risk of type 2 diabetes and cardiovascular mortality. Coffee roasting can greatly modify the quality-quantitative characteristics of bioactive compounds. We compared the effects of two different roasting intensities of the same naturally low-caffeine Arabica coffee variety (Laurina) on glucose and lipid metabolism as well as oxidative stress. METHODS: We performed a double-blind, crossover intervention study. Fourteen healthy male volunteers consumed four cups daily of light roasted coffee (LRC) and dark roasted coffee (DRC), each for 1 wk (intervention period 1 and 2 respectively). One wk washout, with total abstinence from coffee and other possible caffeine sources, preceded each intervention. Data were collected at the end of washout and intervention periods. RESULTS: Changes between washout and intervention periods in glucose concentrations at 2 h post-oral glucose tolerance test, were significantly lower after DRC than LRC intake (-0.6 ± 0.3 and 0.4 ± 0.3 mmol/L, P < 0.03). Changes in ß-cell function, assessed as insulin secretion-sensitivity index-2, were significantly greater after DRC than LRC (34.7 ± 25.0 and -18.8 ± 21.0, P = 0.03). The initial (30 min) post-oral glucose tolerance test area under the curve of glucagon-like peptide-1 was 24± 9% greater (P = 0.03) after DRC than LRC. LRC or DRC did not affect insulin sensitivity. Changes from basal of reduced-to-oxidized glutathione ratio (GSH/GSSG) in erythrocytes were significantly greater after DRC than LRC (+1437 ± 371 and -152 ± 30, P < 0.05). The omega-3 index in erythrocyte membranes was 16± 4% greater (P < 0.001) after DRC than LRC. CONCLUSIONS: DRC consumption improved postload glucose metabolism by increasing incretin and insulin secretions. DRC compared to LRC improved redox balance and increased omega-3 fatty acids. Thus, we suggest greater metabolic benefits related to DRC.