Journal of Dietary Supplements最新文献

Telomeres are nucleotide repeat sequences located at the end of chromosomes that protect them from degradation and maintain chromosomal stability. Telomeres shorten with each cell division; hence telomere length is associated with aging and longevity. Numerous lifestyle factors have been identified that impact the rate of telomere shortening; high vitamin consumption has been associated with longer telomere length, whereas oxidative stress is associated with telomere shortening. In this paper, we sought to determine if a multivitamin mixture containing both vitamins and a blend of polyphenolic compounds, could reduce telomere shortening consequent to an oxidative stress (10 uM H₂O₂ for 8 weeks) in a primary fibroblast cell culture model. Under conditions of oxidative stress, the median and 20^th percentile telomere length were significantly greater (p < 0.05), and the percentage of critically short telomeres (<3000 bp) was significantly less (p < 0.05) in cells treated with the multivitamin mixture at 4, 15 and 60 ug/ml compared to control (0 ug/ml). Median and 20^th percentile telomere shortening rate was also reduced under the same conditions (p < 0.05). Taken together, these findings demonstrate that the multivitamin mixture protects against oxidative stress-mediated telomere shortening in cell culture, findings which may have implications in human health.

Boswellia serrata ole-gum-resin extracts (BSEs) are commonly used as food supplements, especially in osteoarthritis management. The quality standard is established by determining 11-keto-β-boswellic acid (KBA) and acetyl-11-keto-boswellic acid (AKBA) content using high-performance liquid chromatography (HPLC) or assessing the total boswellic acid (TBA) content by titrimetry. The limited geographical distribution of Boswellia species and increasing industrial demand could increase the risk of adulteration in Boswellia-containing products. In this study, 14 BSEs from commercial sources, used in food supplements, were analyzed in comparison with a USP Reference Standard extract. The KBA and AKBA content was determined by HPLC, whereas the TBA content was determined by titration. Targeted UHPLC-high-resolution mass spectrometry (HRMS) was applied to identify the carboxylic acid content in the samples. The ¹H NMR spectra of extracts were also analyzed. Only two products met the criteria for KBA and AKBA content. Although, the TBA content complied with the expected amount, 10 extracts contained citric acid levels of 6-11% even though citric acid is not a cha-racteristic component of BSEs. Our results suggest undeclared addition of citric acid to comply with declared contents of TBA when using titration methods. Incorporation of citric acid to industrial samples - in order to alter the outcomes of the titration analysis - was demonstrated for the first time.

Many high school athletes report using nutritional supplements. Due to a lack of education at the high school level, the use of safe for sports third-party tested nutritional supplements may be limited. To determine the impact of a short online nutritional supplement education program on safe dietary supplement behavior a cross-sectional repeated measures design was used. Therefore, a convenience sample of 106 high school athletes (14-19 years old) was recruited to measure pre-post education difference for nutritional supplement use and third-party tested (TPT) supplements. Additionally, it was analyzed if nutritional supplement related Theory of Planned Behavior (TPB) constructs were associated with athlete choices. The most popular supplements included protein powder (65%), caffeine from beverages (45%), and different types of vitamins (ranging from 38-44%). Consistent use of (safe) third-party tested individual supplements was low, ranging from 35-77% for the most frequently reported supplements. The combined TPB determinants explained 26% of the variance of the intention to use safe supplements (F_{3, 102} = 13.03, p < 0.001, Adj R² = 0.26). The self-reported intention to use third-party tested supplements increased significantly (+7%-36% per individual supplement) after following the education program (Z = -3.288, p = 0.001) resulting in an intentional use of 54-94% TPT supplements. In conclusion, education resulted in more high school athletes reporting future third-party tested supplements use, and TPB construct scores did not change over time but could explain a substantial part of the variance of safe supplement use intentions.

Exogenous ketone monoesters can raise blood β-OHB and lower glucose without other nutritional modifications or invasive procedures. However, unpleasant taste and potential gastrointestinal discomfort may make adherence to supplementation challenging. Two novel ketone supplements promise an improved consumer experience but differ in their chemical properties; it is currently unknown how these affect blood β-OHB and blood glucose compared to the ketone monoester. In a double-blind randomized cross-over pilot study, N=12 healthy individuals (29 ± 5 years, BMI = 25 ± 4 kg/m2, 42% female) participated in three experimental trials with a different ketone supplement providing 10 grams of active ingredient in each; (i) the monoester (R)-3-hydroxybutyl (R)-3-hydroxybutyrate, (ii) D-β-hydroxybutyric acid with R-1,3-butanediol, and (iii) R-1,3-butanediol. Blood β-OHB and glucose were measured via finger prick capillary blood samples at baseline and across 240 minutes post-supplementation. Supplement acceptability, hunger, and gastrointestinal distress were assessed via questionnaires. β-OHB was elevated compared to baseline in all conditions. Total and incremental area under the curve (p < 0.05) and peak β-OHB (p  < 0.001) differed between conditions with highest values seen in the ketone monoester condition. Blood glucose was reduced after consumption of each supplement, with no differences in total and incremental area under the curve across supplements. Supplement acceptability was greatest for D-β-hydroxybutyric acid with R-1,3-butanediol, with no effect on hunger or evidence of gastrointestinal distress across all supplements. All ketone supplements tested raised β-OHB with highest values seen after ketone monoester ingestion. Blood glucose was lowered similarly across the assessed time frame with all three supplements.

Autism spectrum disorder (ASD) is a group of neurodevelopmental disorders defined by a lack of social behaviors, repetitive behaviors and nonverbal interactions, such as limited eye contact, facial expression, and body gesturing. It is not a single condition, but rather a multi-factorial disorder caused by hereditary and non-genetic risk factors, as well as their interaction. According to several studies, the gut microbiota may have a role in the pathophysiology of autism spectrum disorder. Various studies have found differences in the composition of the gastrointestinal (GI) microbiota in children with ASD compared to unaffected siblings and/or healthy unrelated controls. The processes that relate the gut microbiota to brain dysfunctions (the gut-brain axis) in ASD are yet to be fully understood. However, the differences in the gastrointestinal composition might be due to vitamin A deficiency because vitamin A (VA) plays a role in the regulation of the intestinal microbiota. This narrative review discusses the impact of vitamin A deficiency on the gut microbiota composition and tries to understand how this may contribute for the development and severity of ASD.

The use of nutritional supplements can lead to doping risk and no data exist on high school athletes' use of certified third-party tested supplements. A cross-sectional cohort design was developed using an anonymous survey. Descriptive data for supplement use, use of third-party tested supplements, and knowledge in high school athletes were reported. A total of 225 high school athletes, ranging from 14-19 years of age, from a private high school in the western US, were included in the analysis of the results. A total of 94% (n=211) of athletes reported nutritional supplement use within the past year with an average of six (interquartile range: 3-9) individual supplements, ranging from 0-20 supplements per person. Most frequently reported were sports drinks (72%), vitamins (65%), sports bars (60%), protein powder (58%), caffeine (37%, as part of normal beverages, or 13% as a supplement), followed by creatine (23%). A total of 24% claimed to know for sure that all their supplements were third-party tested. In addition, the recognition of third-party testing organization icons was low (46% in supplement users vs. 14% in nonusers). Athletes also scored low in reporting how to find (22%) and how to order (25%) third-party tested supplements. In conclusion, almost all athletes in this study reported the use of multiple nutritional supplements annually. Only one-fourth of the athletes reported consistently using third-party tested supplements. Knowledge of where and how tested supplements could be purchased was limited in this high school athlete population.

There is growing interest of ergogenic aids that deliver supplemental oxygen during exercise and recovery, however, breathing supplemental oxygen via specialist facemasks is often not feasible. Therefore, this study investigated the effect of an oxygen-nanobubble beverage during submaximal and repeated sprint cycling. In a double-blind, randomized, placebo-controlled study, 10 male cyclists (peak aerobic capacity, 56.9 ± 6.1 mL·kg^-1·min^-1; maximal aerobic power, 385 ± 25 W) completed submaximal or maximal exercise after consuming an oxygen-nanobubble (O₂) or placebo (PLA) beverage. Submaximal trials comprised 30-min of steady-state cycling at 60% peak aerobic capacity and 16.1-km time-trial (TT). Maximal trials involved 4 × 30 s Wingate tests interspersed by 4-min recovery. Time-to-completion during the 16.1-km TT was 2.4% faster after O₂ compared with PLA (95% CI = 0.7-4.0%, p = 0.010, d = 0.41). Average power for the 16.1-km TT was 4.1% higher for O₂ vs. PLA (95% CI = 2.1-7.3%, p = 0.006, d = 0.28). Average peak power during the repeated Wingate tests increased by 7.1% for O₂ compared with PLA (p = 0.002, d = 0.58). An oxygen-nanobubble beverage improves performance during submaximal and repeated sprint cycling, therefore may provide a practical and effective ergogenic aid for competitive cyclists.

Type 1 collagen is an abundant structural protein with importance to the skin, eyes, bones, ligaments, tendons, and muscles. Shilajit supplementation has been shown to increase gene expression of collagen synthesis, however, it is unclear if increased gene expression translates to increases in circulating levels. Therefore, the purpose of the present study was to examine the effects of 8 weeks of daily supplementation with 500 mg·d^-1 and 1000 mg·d^-1 of Shilajit versus placebo on serum pro-c1α1, a biomarker of type 1 collagen synthesis. Thirty-five recreationally trained men (mean ± SD: age = 21.1 ± 1.8 yrs; body mass = 80.7 ± 12.4 kg; height = 180.9 ± 6.7 cm) volunteered to participate in this study. Mixed factorial and one-way ANOVAs were used to analyze mean differences between groups, with follow-up t-tests when necessary. Individual subject responses were assessed using the minimal clinically important difference and Chi-squared tests. There were significant (Low dose: p = 0.008, d = 1.2; High dose: p = 0.007, d = 1.3) increases in serum pro-c1α1 from pre- (Low dose: 42.5 ± 12.4 ng·mL^-1; High dose: 42.7 ± 12.7 ng·mL^-1) to post-supplementation (Low dose: 82.3 ± 46.5 ng·mL^-1; High dose: 113.1 ± 78.7 ng·mL^-1) for the low and high dose groups, however, no change (p > 0.05) for the placebo group. A greater proportion (p = 0.03) of subjects exhibited increases in pro-c1α1 that exceeded the minimal clinically important difference in the high dose Shilajit group (75%) compared to the placebo group (30%), but no differences (p = 0.06) between the low dose Shilajit group (69%) and placebo. In conclusion, 8 weeks of Shilajit supplementation with 500 and 1000 mg·d^-1 increased type 1 collagen synthesis as indicated by serum levels of pro-c1α1.