J J Strain

University of Ulster, Aontroim, Northern Ireland, United Kingdom

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Publications (298)1166.14 Total impact

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    ABSTRACT: Context: Vitamin D insufficiency is common among the adolescent population, and may have implications for health outcomes in later life. Few studies have investigated the role of vitamin D status in muscle function and cardiorespiratory fitness (CRF) during adolescence. Objective: The aim of this study was to investigate the association between vitamin D status and fat free mass (FFM), muscle strength, muscle power and CRF in a representative sample of adolescents from Northern Ireland. Design, setting and participants: A cross-sectional study involving 1,015 adolescents (aged 12 and 15 years), who had 25-hydroxyvitamin D [25(OH)D] data available, as part of the Young Hearts Study 2000. Main outcome measures: FFM (kg) and FFM corrected for height [fat free mass index (FFMI); FFM (kg)/height (m(2))], muscle strength (kg), peak muscle power (kW) and VO2 max (CRF; ml/kg/min). Results: Multinomial regression analyses, controlling for environmental and lifestyle factors, demonstrated that boys aged 15 years in the highest tertile of standardized serum 25(OH)D concentration (>51nmol/L) had significantly higher muscle strength (β=3.90, P=<0.001) compared to those in the lowest tertile (<32nmol/L). These results were not evident in any other age-sex group and vitamin D status was not significantly associated with muscle power or CRF in any of the four age-sex groups. Conclusions: These results support a role for vitamin D in muscle function in adolescent males and indicate the need for more research, in this vulnerable age group.
    The Journal of Clinical Endocrinology and Metabolism 10/2015; DOI:10.1210/jc.2015-2956 · 6.21 Impact Factor
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    ABSTRACT: Long-chain n-6 and n-3 PUFA (LC-PUFA), arachidonic acid (AA) (20:4n-6) and DHA (22:6n-3), are critical for optimal brain development. These fatty acids can be consumed directly from the diet, or synthesized endogenously from precursor PUFA by Δ-5 (encoded by FADS1) and Δ-6 desaturases (encoded by FADS2). The aim of this study was to determine the potential importance of maternal genetic variability in FADS1 and FADS2 genes to maternal LC-PUFA status and infant neurodevelopment in populations with high fish intakes. The Nutrition Cohorts 1 (NC1) and 2 (NC2) are longitudinal observational mother-child cohorts in the Republic of Seychelles. Maternal serum LC-PUFA was measured at 28 weeks gestation and genotyping for rs174537 (FADS1), rs174561 (FADS1), rs3834458 (FADS1-FADS2) and rs174575 (FADS2) was performed in both cohorts. The children completed the Bayley Scales of Infant Development II (BSID-II) at 30 months in NC1 and at 20 months in NC2. Complete data were available for 221 and 1310 mothers from NC1 and NC2 respectively. With increasing number of rs3834458 minor alleles, maternal concentrations of AA were significantly decreased (NC1 p=0.004; NC2 p<0.001) and precursor:product ratios for linoleic acid (LA) (18:2n-6)-to-AA (NC1 p<0.001; NC2 p<0.001) and α-linolenic acid (ALA) (18:3n-3)-to-DHA were increased (NC2 p=0.028). There were no significant associations between maternal FADS genotype and BSID-II scores in either cohort. A trend for improved PDI was found among infants born to mothers with the minor rs3834458 allele.In these high fish-eating cohorts, genetic variability in FADS genes was associated with maternal AA status measured in serum and a subtle association of the FADS genotype was found with neurodevelopment.
    Prostaglandins Leukotrienes and Essential Fatty Acids 09/2015; DOI:10.1016/j.plefa.2015.08.004 · 2.35 Impact Factor
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    ABSTRACT: vitamin D deficiency is prevalent in older adults living in Northern Europe and is influenced by several factors which may vary significantly with age. we aimed to investigate the determinants of 25-hydroxyvitamin D [25(OH)D] in older Irish adults and in particular to examine the effect of supplement use and surrogate markers of sun exposure. subjects were non-institutionalised community dwelling Irish adults aged over 60 years who were participants of a large cross-sectional study comprising three disease defined cohorts. Serum 25(OH)D was measured by liquid chromatography mass spectroscopy. Associations between 25(OH)D and potential confounders were explored in forward regression models in each cohort. the three cohorts comprised 1895, 1233 and 1316 participants (respective mean ages 70.1, 71.0 and 80.4 years). Statistical models explained between a fifth to a third of the variation in 25(OH)D. Supplement use and global solar radiation were positive predictors of 25(OH)D in all cohorts whereas the only universal negative predictor was body mass index. Supplement use was associated with a mean increase in 25(OH)D of between 21.4 and 35.4 nmol/l. The other main predictors varied by cohort but included sun holiday travel, enjoyment of sunshine when outside, use of vitamin D fortified milk, smoking, oily fish and egg consumption and physical frailty. supplement use was the most important determinant of vitamin D status. Vitamin D fortified milk and spending time in the sun, even in the oldest old may also be useful strategies to improve 25(OH)D. © The Author 2015. Published by Oxford University Press on behalf of the British Geriatrics Society. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
    Age and Ageing 08/2015; 44(5). DOI:10.1093/ageing/afv090 · 3.64 Impact Factor
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    ABSTRACT: Purpose Palmaria palmata (P. Palmata) is reported to contain anti-inflammatory and antioxidant compounds albeit no study has investigated these effects in humans. Methods A randomised parallel placebo-controlled human intervention study was carried out to investigate the effect of consuming P. Palmata (5 g/day) incorporated into a bread on serum markers of inflammation [C-reactive protein (CRP); cytokine analysis] with secondary analysis investigating changes in lipids (cholesterol, triglycerides), thyroid function [thyroid-stimulating hormone (TSH)] and antioxidant status ferric reducing antioxidant power. ANCOVA with baseline values as covariates, controlling for age, BMI, sex and smoking status, was used to compare differences between treatment groups over time . In vitro studies investigated the inflammatory activity of P. Palmata extracts (hot water, cold water and ethanol extract), protein extracts and associated protein hydrolysates using a Caco-2 inflammation cell model. Results Consumption of P. Palmata-enriched bread significantly increased serum CRP (+16.1 %, P = 0.011), triglycerides (+31.9 %, P = 0.001) and TSH (+17.2 %, P = 0.017) when compared to the control group. In vitro evaluation of P. palmata extracts and protein hydrolysates identified a significant induction of IL-8 secretion by Caco-2 cells, and the hot water P. palmata extract was shown to increase adipocyte glycerol release (P < 0.05). Conclusion Evidence from this human study suggests that P. palmata stimulates inflammation, increases serum triglycerides and alters thyroid function; however, these changes are not likely to impact health as changes remained within the normal clinical range. The data from the in vitro study provided indications that IL-8 may contribute to the apparent immunostimulation noted in the human study.
    European Journal of Nutrition 08/2015; 54(275). DOI:10.1007/s00394-015-1011-1 · 3.47 Impact Factor
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    ABSTRACT: Ireland has traditionally operated a liberal policy of voluntary fortification, but little is known about how this practice, along with supplement use, affects population intakes and status of folate and vitamin B-12. The aim was to examine the relative impact of voluntary fortification and supplement use on dietary intakes and biomarker status of folate and vitamin B-12 in Irish adults. Folic acid and vitamin B-12 from fortified foods and supplements were estimated by using brand information for participants from the cross-sectional National Adult Nutrition Survey 2008-2010. Dietary and biomarker values were compared between 6 mutually exclusive consumption groups formed on the basis of folic acid intake. The consumption of folic acid through fortified foods at low, medium, and high levels of exposure [median (IQR) intakes of 22 (13, 32), 69 (56, 84), and 180 (137, 248) μg/d, respectively]; from supplements [203 (150, 400) μg/d]; or from both sources [287 (220, 438) μg/d] was associated with significantly higher folate intakes and status compared with nonconsumption of folic acid (18% of the population). Median (IQR) red blood cell (RBC) folate increased significantly from 699 (538, 934) nmol/L in nonconsumers to 1040 (83, 1390) nmol/L in consumers with a high intake of fortified foods (P < 0.001), with further nonsignificant increases in supplement users. Supplement use but not fortification was associated with significantly higher serum vitamin B-12 concentrations relative to nonconsumers (P < 0.001). Two-thirds of young women had suboptimal RBC folate for protection against neural tube defects (NTDs); among nonconsumers of folic acid, only 16% attained optimal RBC folate. The consumption of voluntarily fortified foods and/or supplement use was associated with significantly higher dietary intakes and biomarker status of folate in Irish adults. Of concern, the majority of young women remain suboptimally protected against NTDs. © 2015 American Society for Nutrition.
    American Journal of Clinical Nutrition 04/2015; 101(6). DOI:10.3945/ajcn.115.107151 · 6.77 Impact Factor
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    ABSTRACT: Studies investigating obesity and cardiometabolic risk have focused on 'at-risk' populations and methodological inconsistencies have produced equivocal findings. The present cross-sectional study investigated indices of body composition as predictors of cardiometabolic risk and their relationship with inflammation in apparently healthy young adults. A fasting blood sample was taken from consenting adults (160 males, 32 females, aged 18-40 years) for assessment of cardiometabolic risk markers (blood pressure, lipid profiles and insulin resistance) and inflammatory markers (C-reactive protein, tumour necrosis factor-α, interleukin-6, interleukin-10 and adiponectin). Together with anthropometry, fat mass (FM) and fat-free mass (FFM) were determined by dual-energy X-ray absorptiometry. FM was expressed in absolute terms (kg), as well as relative to total body weight (%), height [FM index (FMI, kg m(-2) )] and FFM (FM : FFM,%). Although anthropometric indices were associated with most cardiometabolic risk markers, the strongest relationship was observed with FMI. Relative to having a low cardiometabolic risk (≤2 markers above clinically relevant cut-offs), each kg m(-2) increase in FMI, increased the likelihood of having an increased cardiometabolic risk by 29% (odds ratio = 1.29; 95% confidence interval = 1.12-1.49). Inflammatory markers were not associated with body composition or cardiometabolic risk. FMI was the strongest predictor of overall cardiometabolic risk but not inflammation per se. However, anthropometric indices, such as body mass index and waist-to-height ratio, remain valuable surrogate measures of adiposity in this group, particularly when risk markers are considered independently. © 2015 The British Dietetic Association Ltd.
    Journal of Human Nutrition and Dietetics 02/2015; DOI:10.1111/jhn.12295 · 1.99 Impact Factor
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    Bulletin of the World Health Organisation 02/2015; 93(2):132. DOI:10.2471/BLT.14.141911 · 5.09 Impact Factor
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    ABSTRACT: The bran and particularly the aleurone fraction of wheat are high in betaine and other physiological methyl donors, which may exert beneficial physiological effects. We conducted two randomised, controlled, cross-over postprandial studies to assess and compare plasma betaine and other methyl donor-related responses following the consumption of minimally processed bran and aleurone fractions (study A) and aleurone bread (study B). For both studies, standard pharmacokinetic parameters were derived for betaine, choline, folate, dimethylglycine (DMG), total homocysteine and methionine from plasma samples taken at 0, 0·5, 1, 2 and 3 h. In study A (n 14), plasma betaine concentrations were significantly and substantially elevated from 0·5 to 3 h following the consumption of both bran and aleurone compared with the control; however, aleurone gave significantly higher responses than bran. Small, but significant, increases were also observed in DMG measures; however, no significant responses were observed in other analytes. In study B (n 13), plasma betaine concentrations were significantly and substantially higher following consumption of the aleurone bread compared with the control bread; small, but significant, increases were also observed in DMG and folate measures in response to consumption of the aleurone bread; however, no significant responses were observed in other analytes. Peak plasma betaine concentrations, which were 1·7-1·8 times the baseline levels, were attained earlier following the consumption of minimally processed aleurone compared with the aleurone bread (time taken to reach peak concentration 1·2 v. 2·1 h). These results showed that the consumption of minimally processed wheat bran, and particularly the aleurone fraction, yielded substantial postprandial increases in plasma betaine concentrations. Furthermore, these effects appear to be maintained when aleurone was incorporated into bread.
    British Journal Of Nutrition 01/2015; 113(03):1-9. DOI:10.1017/S0007114514003778 · 3.45 Impact Factor
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    Proceedings of The Nutrition Society 01/2015; 74(OCE1). DOI:10.1017/S0029665115000683 · 5.27 Impact Factor
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    Proceedings of The Nutrition Society 01/2015; 74(OCE4). DOI:10.1017/S0029665115002529 · 5.27 Impact Factor
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    Proceedings of The Nutrition Society 01/2015; 74(OCE1). DOI:10.1017/S002966511500083X · 5.27 Impact Factor

  • Proceedings of The Nutrition Society 01/2015; 74(OCE5). DOI:10.1017/S0029665115003821 · 5.27 Impact Factor

  • Proceedings of The Nutrition Society 01/2015; 74(OCE2). DOI:10.1017/S0029665115001810 · 5.27 Impact Factor
  • E. Laird · H. McNulty · M. Ward · L. Hoey · J.J. Strain · M. Casey · C. Cunningham · A.M. Molloy ·

    Proceedings of The Nutrition Society 01/2015; 74(OCE4). DOI:10.1017/S0029665115003055 · 5.27 Impact Factor
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    Proceedings of The Nutrition Society 01/2015; 74(OCE4). DOI:10.1017/S002966511500302X · 5.27 Impact Factor
  • C McGarel · K Pentieva · J J Strain · H McNulty ·
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    ABSTRACT: Nutrition plays a fundamental role in supporting the structural and functional development of the human brain from conception, throughout early infancy and extending into later life. A growing body of evidence suggests that folate and the metabolically related B-vitamins are essential for brain health across all age groups, owing to their specific roles in C1 metabolism and particularly in the production of S-adenosylmethionine, a universal methyl donor essential for the production of neurotransmitters. Emerging, though not entirely consistent, evidence suggests that maternal folate status throughout pregnancy may influence neurodevelopment and behaviour of the offspring. Furthermore optimal B-vitamin status is associated with better cognitive health in ageing. Of note, a recent clinical trial provided evidence that supplementation with folic acid and related B-vitamins over a 2-year-period reduced global and regional brain atrophy, as measured by MRI scan in older adults. In terms of potential mechanisms, the effects of these B-vitamins on cognitive health may be independent or may be mediated by nutrient-nutrient and/or relevant gene-nutrient interactions. Furthermore, a new area of research suggests that the in utero environment influences health in later life. Folate, an important cofactor in C1 metabolism, is indirectly involved in DNA methylation, which in turn is considered to be one of the epigenetic mechanisms that may underlie fetal programming and brain development. The present review will explore the evidence that supports a role for folate and the related B-vitamins in brain health across the lifecycle, and potential mechanisms to explain such effects.
    Proceedings of The Nutrition Society 11/2014; 74(01):1-10. DOI:10.1017/S0029665114001554 · 5.27 Impact Factor
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    ABSTRACT: Background Epidemiologic studies have been inconclusive regarding the impact of co-exposure to long chain polyunsaturated fatty acids (LCPUFA) and methyl mercury (MeHg) from fish consumption during pregnancy on measures of fetal development. Objectives We evaluated the association between birth weight and prenatal maternal LCPUFA status and MeHg exposure in the Republic of Seychelles. Methods We measured LCPUFA in maternal whole blood collected at 28 weeks of gestation and following delivery, and MeHg in maternal hair obtained at delivery. There were 230 births with complete data on birth weight and covariates. Multiple linear regression models controlled for infant sex, gestational age, maternal age, smoking during pregnancy, intrapartum weight gain, pre-pregnancy body mass index, maternal socioeconomic status, parity, gestational diabetes, and alcohol use during pregnancy. Results The average birth weight was 3,252 g (range 1654-4450) and the average gestational age was 39 weeks (range 34-41). Prenatal MeHg exposure and maternal LCPUFA status were not associated with birth weight. Infant sex and length of gestation were the only predictors, with male sex and increased gestational age consistently associated with greater birth weight. Conclusions These findings do not support a relationship between prenatal exposure to LCPUFA and/or MeHg from fish consumption and birth weight.
    Annals of epidemiology 04/2014; 24(4). DOI:10.1016/j.annepidem.2014.01.002 · 2.00 Impact Factor
  • M Clarke · M Ward · J J Strain · L Hoey · W Dickey · H McNulty ·
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    ABSTRACT: Osteoporosis, a metabolic skeletal disease characterised by decreased bone mass and increased fracture risk, is a growing public health problem. Among the various risk factors for osteoporosis, calcium and vitamin D have well-established protective roles, but it is likely that other nutritional factors are also implicated. This review will explore the emerging evidence supporting a role for certain B-vitamins, homocysteine and the 677C→T polymorphism in the gene encoding the folate-metabolising enzyme methylenetetrahydrofolate reductase, in bone health and disease. The evidence, however, is not entirely consistent and as yet no clear mechanism has been defined to explain the potential link between B-vitamins and bone health. Coeliac disease, a common condition of malabsorption, induced by gluten ingestion in genetically susceptible individuals, is associated with an increased risk both of osteoporosis and inadequate B-vitamin status. Given the growing body of evidence linking low bone mineral density and/or increased fracture risk with low B-vitamin status and elevated homocysteine, optimal B-vitamin status may play an important protective role against osteoporosis in coeliac disease; to date, no trial has addressed this possible link.
    Proceedings of The Nutrition Society 02/2014; 73(02):1-10. DOI:10.1017/S0029665114000044 · 5.27 Impact Factor
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    ABSTRACT: Context: Inadequate vitamin D status is common within elderly populations and may be implicated in the etiology of autoimmune disease and inflammation. Few studies have investigated the relationship between vitamin D status and age-related immune dysfunction in humans. Objective: The aim of this study was to investigate the association between vitamin D status and immune markers of inflammation in a large sample of older adults. Design, Setting, and Participants: An observational investigation of 957 Irish adults (>60 years of age) recruited in Northern Ireland (55°N latitude) as part of the Trinity Ulster Department of Agriculture aging cohort study. Main Outcome Measure: We measured serum 25-hydroxyvitamin D (25(OH)D) by liquid chromatography tandem mass spectrometry and serum cytokines IL-6, TNF-α, IL-10, and C-reactive protein (CRP) by ELISA. Results: Concentrations of IL-6, CRP, and the ratios of IL-6 to IL-10 and CRP to IL-10 were significantly higher in individuals with deficient (<25 nmol/L) serum 25(OH)D compared with those with sufficient (>75 nmol/L) status after adjustment for age, sex, and body mass index (P < .05). Vitamin D status was a significant predictor of the IL-6 to IL-10 cytokine ratio, and those participants defined as deficient were significantly more likely to have an IL-6 to IL-10 ratio >2:1 compared with those defined as sufficient. Conclusions: This study demonstrated significant associations between low vitamin D status and markers of inflammation (including the ratio of IL-6 to IL-10) within elderly adults. These findings suggest that an adequate vitamin D status may be required for optimal immune function, particularly within the older adult population.
    The Journal of Clinical Endocrinology and Metabolism 02/2014; 99(5):jc20133507. DOI:10.1210/jc.2013-3507 · 6.21 Impact Factor
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    ABSTRACT: This 24-mo randomized, double-blind, controlled trial aimed to examine whether supplementation with a natural marine-derived multi-mineral supplement rich in calcium (Ca) taken alone and in conjunction with short-chain fructo-oligosaccharide (scFOSs) has a beneficial effect on bone mineral density (BMD) and bone turnover markers (BTMs) in postmenopausal women. A total of 300 non-osteoporotic postmenopausal women were randomly assigned to daily supplements of 800 mg of Ca, 800 mg of Ca with 3.6 g of scFOS (CaFOS), or 9 g of maltodextrin. BMD was measured before and after intervention along with BTMs, which were also measured at 12 mo. Intention-to-treat ANCOVA identified that the change in BMD in the Ca and CaFOS groups did not differ from that in the maltodextrin group. Secondary analysis of changes to BTMs over time identified a greater decline in osteocalcin and C-telopeptide of type I collagen (CTX) in the Ca group compared with the maltodextrin group at 12 mo. A greater decline in CTX was observed at 12 mo and a greater decline in osteocalcin was observed at 24 mo in the CaFOS group compared with the maltodextrin group. In exploratory subanalyses of each treatment group against the maltodextrin group, women classified with osteopenia and taking CaFOS had a smaller decline in total-body (P = 0.03) and spinal (P = 0.03) BMD compared with the maltodextrin group, although this effect was restricted to those with higher total-body and mean spinal BMD at baseline, respectively. Although the change in BMD observed did not differ between the groups, the greater decline in BTMs in the Ca and CaFOS groups compared with the maltodextrin group suggests a more favorable bone health profile after supplementation with Ca and CaFOS. Supplementation with CaFOS slowed the rate of total-body and spinal bone loss in postmenopausal women with osteopenia-an effect that warrants additional investigation. This trial was registered at www.controlled-trials.com as ISRCTN63118444.
    Journal of Nutrition 01/2014; 144(3). DOI:10.3945/jn.113.188144 · 3.88 Impact Factor

Publication Stats

14k Citations
1,166.14 Total Impact Points


  • 1988-2015
    • University of Ulster
      • • Northern Ireland Centre for Food & Health (NICHE)
      • • School of Biomedical Sciences
      • • Centre for Molecular Biosciences
      • • Biomedical Sciences Research Institute
      Aontroim, Northern Ireland, United Kingdom
  • 2008-2011
    • University of Rochester
      • • Division of General Medicine
      • • Department of Environmental Medicine
      Rochester, New York, United States
  • 2005
    • The Hong Kong Polytechnic University
      • Faculty of Health and Social Sciences
      Hong Kong, Hong Kong
  • 2002
    • University of Bergen
      • Section of Pharmacology
      Bergen, Hordaland, Norway
  • 2001
    • University of Toronto
      • Department of Nutritional Sciences
      Toronto, Ontario, Canada
  • 1998
    • University of North Carolina at Chapel Hill
      • Department of Epidemiology
      North Carolina, United States
  • 1993
    • Queen's University Belfast
      • Institute of Clinical Sciences
      Béal Feirste, N Ireland, United Kingdom
    • Ninewells Hospital
      Dundee, Scotland, United Kingdom
  • 1992
    • The University of Sheffield
      Sheffield, England, United Kingdom