Sohail Mushtaq

Correcting a marginal riboflavin deficiency improves hematologic status in young women in the United Kingdom (RIBOFEM)

BACKGROUND Moderate riboflavin deficiency is prevalent in certain population groups in affluent countries, but the functional significance of this deficiency is not clear. Studies have indicated a role for riboflavin in the absorption and use of iron. OBJECTIVE We investigated the effect of riboflavin supplementation on hematologic status in a group of moderately riboflavin-deficient women aged 19-25 y in the United Kingdom. DESIGN One hundred twenty-three women with biochemical evidence of riboflavin deficiency [erythrocyte glutathione reductase activation coefficient (EGRAC) >1.40] were randomly assigned to receive 2 or 4 mg riboflavin or a placebo for 8 wk. Measurements of hematologic status were made pre- and postsupplementation, and dietary intakes were also assessed; iron absorption was measured in a subgroup of women. RESULTS One hundred nineteen women completed the intervention. The use of a riboflavin supplement for 8 wk elicited a significant improvement in riboflavin status with a dose response (P < 0.0001). For women who received supplemental riboflavin, an increase in hemoglobin status correlated with improved riboflavin status (P < 0.02). Women in the lowest tertile of riboflavin status at baseline (EGRAC >1.65) showed a significantly greater increase in hemoglobin status in response to the supplement than did women in the first and second tertiles (P < 0.01). Dietary iron intake and iron absorption did not change during the study. CONCLUSIONS Moderately poor riboflavin status can affect iron status: the lower the riboflavin status, the greater the hematologic benefits of improving status. The results also suggest that consideration should be given to raising the currently accepted EGRAC threshold for deficiency. This trial was registered at controlled-trials.com as ISRCTN35811298.

Estimation of cis-9, trans-11 conjugated linoleic acid content in UK foods and assessment of dietary intake in a cohort of healthy adults.

Dietary conjugated linoleic acid (CLA) from ruminant-derived foods may be potentially beneficial to health. The quantity of cis-9, trans-11 CLA and trans-10, cis-12 CLA in a range of UK foodstuffs (112 foods) was determined using triple-column silver ion HPLC. The cis-9, trans-11 CLA content ranged from 1.9 mg/g lipid (mild Cheddar) to 7.3 mg/g lipid (processed cheese) in cheeses, from 0.9 mg/g lipid (ice cream) to 3.7 mg/g lipid (double cream) in non-cheese dairy products, and from 2.9 mg/g lipid (Swedish meatballs) to 6.0 mg/g lipid (minced lamb) in meat products. cis-9, trans-11 CLA concentrations for chocolate and sweets ranged from 0.1 mg/g lipid (hot chocolate) to 4.8 mg/g lipid (buttermint). The trans-10, cis-12 CLA isomer was undetected or negligible in the food samples examined. To provide information about dietary cis-9, trans-11 CLA intakes in the UK, a study was performed to estimate the daily intake of CLA in a cohort of eighteen healthy volunteers (nine female and nine male; aged 21-60 years; mean BMI = 24.0 kg/m2 (sd 2.2)) with a 7-d weighed food record. This information combined with the CLA isomer contents of UK foodstuffs was used to estimate the daily intake of the cohort. The mean daily intake of cis-9, trans-11 CLA was estimated to be 97.5 (sd 73.3) mg/d. Due to its potential health benefits, it is important to determine the CLA content of food and dietary intake as these data will be useful in determining the role of CLA in health and disease.

Erythrocyte pyridoxamine phosphate oxidase activity: a potential biomarker of riboflavin status?

BACKGROUND Riboflavin status is commonly measured by the in vitro stimulation of erythrocyte glutathione reductase with flavin adenine dinucleotide and expressed as an erythrocyte glutathione reductase activation coefficient (EGRAC). However, this assay is insensitive to poor riboflavin status in subjects with glucose-6-phosphate dehydrogenase (G6PD) deficiency. Because G6PD deficiency is common in parts of the world where ariboflavinosis is endemic, it is important to have a measure of riboflavin status that is unaffected by differences in G6PD status. OBJECTIVE The objective was to further develop and validate a fluorometric assay for pyridoxamine phosphate oxidase (PPO) activity as a measure of riboflavin status. DESIGN A fluorometric assay was optimized for the flavin-dependent enzyme PPO in erythrocytes. Hemolysates from a previous riboflavin intervention study (2- and 4-mg riboflavin supplements) were used to investigate the responsiveness of the method to changes in riboflavin intake. RESULTS PPO activity and the PPO activation coefficient (PPOAC) were used to assess riboflavin status. Both PPO activity and PPOAC responded to riboflavin supplements (P < 0.01), but only PPO showed a dose response (P < 0.001). The change from baseline to after the intervention in PPOAC and PPO enzyme activity was significantly inversely correlated (P < 0.001). Both PPO activity and PPOAC were strongly correlated with EGRAC (P < 0.001). Additionally, both PPOAC and EGRAC showed a significant inverse correlation with dietary riboflavin intake (P < 0.01); PPO activity was positively correlated with riboflavin intake (P < 0.01). CONCLUSION PPO activity could be used as a biomarker for measuring riboflavin status, especially in populations with a high prevalence of G6PD deficiency. This trial is registered at www.isrctn.org as ISRCTN35811298.

Impact of vitamin D supplementation on endothelial and inflammatory markers in adults: A systematic review

This systematic review aims to evaluate randomised controlled trials (RCTs) investigating the effect of vitamin D supplementation on endothelial function and inflammation in adults. An electronic search of published randomised controlled trials, using Cochrane, Pubmed and Medline databases was conducted, with the search terms related to vitamin D and endothelial function. Inclusion criteria were RCTs in adult humans with a measure of vitamin D status using serum/plasma 25(OH)D and studies which administered the intervention through the oral route. Among the 1107 studies retrieved, 29 studies met the full inclusion criteria for this systematic review. Overall, 8 studies reported significant improvements in the endothelial/inflammatory biomarkers/parameters measured. However, in 2 out of the 8 studies, improvements were reported at interim time points, but improvements were absent post-intervention. The remaining 21 trial studies did not show significant improvements in the markers of interest measured. Evidence from the studies included in this systematic review did not demonstrate that vitamin D supplementation in adults, results in an improvement in circulating inflammatory and endothelial function biomarkers/parameters. This systematic review does not therefore support the use of vitamin D supplementation as a therapeutic or preventative measure for CVD in this respect.

Study Protocol: Randomised controlled trial to investigate the functional significance of marginal riboflavin status in young women in the UK (RIBOFEM)

BackgroundThe functional significance of moderate riboflavin deficiency as it is currently assessed is not well understood. Animal and human studies have suggested a role for riboflavin in the absorption and mobilisation of iron and as such may be important in maintaining haematological status. Recent National Diet and Nutrition Surveys in the United Kingdom have shown that young women in particular are at risk of moderate riboflavin deficiency and low iron status.Methods/DesignA randomised placebo controlled intervention trial was conducted to investigate the effect of riboflavin supplementation on various measures of haematological status in a group of moderately riboflavin deficient young women aged 19 to 25 years. Women who were low milk consumers were initially screened for riboflavin status as assessed by the erythrocyte glutathione reductase activation coefficient assay (EGRAC). One hundred and twenty three women with EGRAC values >1.40 were randomised to receive 2 mg, 4 mg riboflavin or placebo for 8 weeks. In addition 36 of these women were randomly allocated to an iron bioavailability study to investigate the effect of the intervention on the absorption or utilisation of iron using an established red cell incorporation technique.DiscussionOne hundred and nineteen women completed the intervention study, of whom 36 completed the bioavailability arm. Compliance was 96 ± 6% (mean ± SD). The most effective recruitment strategy for this gender and age group was e-communication (e-mail and website). The results of this study will clarify the functional significance of the current biochemical deficiency threshold for riboflavin status and will inform a re-evaluation of this biochemical threshold.Trial RegistrationCurrent Controlled Trials Registration No. ISRCTN35811298

A Pilot Study to Evaluate Haemostatic Function, following Shock Wave Lithotripsy (SWL) for the Treatment of Solitary Kidney Stones

Purpose The number of patients undergoing shock wave lithotripsy (SWL) in the UK for solitary unilateral kidney stones is increasing annually. The development of postoperative complications such as haematuria and sepsis following SWL is likely to increase. Comparing a range of biological markers with the aim of monitoring or predicting postoperative complications following SWL has not been extensively researched. The main purpose of this pilot-study was to test the hypothesis that SWL results in changes to haemostatic function. Subsequently, this pilot-study would form a sound basis to undertake future investigations involving larger cohorts. Methods Twelve patients undergoing SWL for solitary unilateral kidney stones were recruited. From patients (8 male and 4 females) aged between 31–72 years (median—43 years), venous blood samples were collected pre-operatively (baseline), at 30, 120 and 240 minutes postoperatively. Specific haemostatic biomarkers [platelet counts, prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen, D-dimer, von Willebrand Factor (vWF), sE-selectin and plasma viscosity (PV)] were measured. Results Platelet counts and fibrinogen concentration were significantly decreased following SWL (p = 0.027 and p = 0.014 respectively), while D-dimer and vWF levels significantly increased following SWL (p = 0.019 and p = 0.001 respectively). PT, APTT, sE-selectin and PV parameters were not significantly changed following SWL (p>0.05). Conclusions Changes to specific biomarkers such as plasma fibrinogen and vWF suggest that these represent a more clinically relevant assessment of the extent of haemostatic involvement following SWL. Analysis of such markers, in the future, may potentially provide valuable data on “normal” response after lithotripsy, and could be expanded to identify or predict those patients at risk of coagulopathy following SWL. The validation and reliability will be assessed through the assessment of larger cohorts.

A 1-h time interval between a meal containing iron and consumption of tea attenuates the inhibitory effects on iron absorption: a controlled trial in a cohort of healthy UK women using a stable iron isotope

Background: Tea has been shown to be a potent inhibitor of nonheme iron absorption, but it remains unclear whether the timing of tea consumption relative to a meal influences iron bioavailability.Objective: The aim of the study was to investigate the effect of a 1-h time interval of tea consumption on nonheme iron absorption in an iron-containing meal in a cohort of iron-replete, nonanemic female subjects with the use of a stable isotope (57Fe).Design: Twelve women (mean ± SD age: 24.8 ± 6.9 y) were administered a standardized porridge meal extrinsically labeled with 4 mg 57Fe as FeSO4 on 3 separate occasions, with a 14-d time interval between each test meal (TM). The TM was administered with water (TM-1), with tea administered simultaneously (TM-2), and with tea administered 1 h postmeal (TM-3). Fasted venous blood samples were collected for iron isotopic analysis and measurement of iron status biomarkers. Fractional iron absorption was estimated by the erythrocyte iron incorporation method.Results: Iron absorption was 5.7% ± 8.5% (TM-1), 3.6% ± 4.2% (TM-2), and 5.7% ± 5.4% (TM-3). Mean fractional iron absorption was found to be significantly higher (2.2%) when tea was administered 1 h postmeal (TM-3) than when tea was administered simultaneously with the meal (TM-2) (P = 0.046). An ∼50% reduction in the inhibitory effect of tea (relative to water) was observed, from 37.2% (TM-2) to 18.1% (TM-3).Conclusions: This study shows that tea consumed simultaneously with an iron-containing porridge meal leads to decreased nonheme iron absorption and that a 1-h time interval between a meal and tea consumption attenuates the inhibitory effect, resulting in increased nonheme iron absorption. These findings are not only important in relation to the management of iron deficiency but should also inform dietary advice, especially that given to those at risk of deficiency. This trial was registered at clinicaltrials.gov as NCT02365103.

Estimates of fibre intake and percentage of the population with intake below the dietary reference values (DRVs) in England (1991–2015)

F. Amirabdollahian, B. Buczkowski, S. Mushtaq and I.G. Davies School of Health Sciences, Liverpool Hope University, Liverpool, L16 9JD, Department of Food and Tourism Management, Manchester Metropolitan University, Manchester, M15 6BG, Department of Clinical Sciences and Nutrition, University of Chester, Chester, CH2 2AS, Faculty of Education, Health and Community, Liverpool John Moores University, Liverpool L17 6BD and Northwest Research Consortium for Nutrition

Dietary supplementation with n-3 fatty acids (n-3 FA) for 4 weeks reduces post-exercise fatigue and delayed onset muscle soreness (DOMS) in trained male athletes

High intensity exercise in the form of eccentric contractions can lead to the formation of free radicals, stimulating an inflammatory response. Consumption of n-3 FA may help modify inflammation and immune reactions beneficial to health by decreasing interleukin-6, tumour necrosis factor-alpha and C-reactive protein. For trained athletes to improve athletic performance, recovery from training is important and DOMS is frequently experienced following eccentric exercise, impacting negatively on strength. The Western diet is however, characterised by a high n-6 FA consumption relative to n-3 FA, formulating ratios often in excess of 16:1. The use of non-steroidal anti-inflammatory drugs in the form of n-3 FA has been investigated by a number of clinical trials in untrained athletes, but whether this can be translated into attenuating exercise induced inflammation in trained athletes is still under investigation. A double-blind, randomised controlled trial was conducted in 22 trained male athletes who supplemented their diet with either 3000 mg/d of fish oil (gel capsules) consisting of 990 mg eicosapentaenoic acid (EPA) and 660 mg docosahexaenoic acid (DHA) (n= 11), or 3000 mg/d olive oil placebo (n= 11), for 28d. Participants underwent 3 sets of eccentric bicep curls in their dominant arm until failure and arm circumference, number of repetitions completed and DOMS/fatigue scores via visual analogue scale (VAS) were recorded at 0, 24 and 48 h after exercise, pre and post supplementation. No group performed better during the eccentric bicep test, pre and post supplementation, and at baseline, no differences were observed between groups for DOMS and fatigue. However, post supplementation, DOMS was significantly lower at 24 h (P = 0·005) and 48 h (P = 0·002) and fatigue was significantly lower at 24 h (P = 0·043) and 48 h post exercise (P < 0·001) in the n-3 FA group compared to the placebo group (Fig. 1). These findings indicate that n-3 FA supplementation has the potential to promote recovery and subsequently increase athletic performance in trained male athletes and may be a useful ergogenic aid. Possible anti-inflammatory mechanisms of n-3 FA should be further investigated using specific biomarkers of inflammation.

Acute and chronic effects of beetroot supplementation on blood pressure and arterial stiffness in humans

Dietary supplementation of beetroot juice, containing nitratea potent vasodilation agent, has been shown to be vasoprotective, and dose dependent decreases in blood pressure (BP) have been previously demonstrated. To our knowledge there has been only one study investigating the effect of beetroot supplementation in humans on arterial stiffness, measured using pulsewave velocity (PWV) and, although there was no effect of supplementation on PWV, there was a significant reduction due to beetroot supplementation in acute diastolic BP (3hrs, P= 0·023). A double-blind, randomised, cross-over intervention trial was carried out in a cohort of 12 healthy male participants (mean age (SEM) = 43 (2·1) yrs, BMI = 27·8 (1·1) kg.m) who underwent both beetroot juice and placebo supplementation for 14 days. The aim of the study was to assess the effect of 6·45 mmol of nitrate in a concentrated 70 ml beetroot drink (James White Ltd, Ipswich, UK) on systolic and diastolic BP, mean arterial pressure (MAP) and arterial stiffness (PWV, aortic augmentation index (Aix), brachial Aix) in humans. BP and arterial stiffness measurements weretaken using PWV (Arteriograph, TensioMed,Hungary). Measurements were taken intriplicate at baseline, 3 hours post-supplementation (either beetroot juice orplacebo) and post-intervention (day 15). This was followed by a 7-day washoutperiod before participants were transferred to the alternate supplement.