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Clinically Relevant Herb-Micronutrient Interactions: When Botanicals, Minerals, and Vitamins Collide.
Gurley, BJ, Tonsing-Carter, A, Thomas, SL, Fifer, EK
Advances in nutrition (Bethesda, Md.). 2018;(4):524S-532S
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Abstract
The ability of certain foods to impair or augment the absorption of various vitamins and minerals has been recognized for many years. However, the contribution of botanical dietary supplements (BDSs) to altered micronutrient disposition has received little attention. Almost half of the US population uses some type of dietary supplement on a regular basis, with vitamin and mineral supplements constituting the majority of these products. BDS usage has also risen considerably over the last 2 decades, and a number of clinically relevant herb-drug interactions have been identified during this time. BDSs are formulated as concentrated plant extracts containing a plethora of unique phytochemicals not commonly found in the normal diet. Many of these uncommon phytochemicals can modulate various xenobiotic enzymes and transporters present in both the intestine and liver. Therefore, it is likely that the mechanisms underlying many herb-drug interactions can also affect micronutrient absorption, distribution, metabolism, and excretion. To date, very few prospective studies have attempted to characterize the prevalence and clinical relevance of herb-micronutrient interactions. Current research indicates that certain BDSs can reduce iron, folate, and ascorbate absorption, and others contribute to heavy metal intoxication. Researchers in the field of nutrition may not appreciate many of the idiosyncrasies of BDSs regarding product quality and dosage form performance. Failure to account for these eccentricities can adversely affect the outcome and interpretation of any prospective herb-micronutrient interaction study. This review highlights several clinically relevant herb-micronutrient interactions and describes several common pitfalls that often beset clinical research with BDSs.
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Have adults lost their sense of play? An observational study of the social dynamics of physical (in)activity in German and Hawaiian leisure settings.
Thiel, A, Thedinga, HK, Thomas, SL, Barkhoff, H, Giel, KE, Schweizer, O, Thiel, S, Zipfel, S
BMC public health. 2016;:689
Abstract
BACKGROUND Physical inactivity is one of the biggest health problems nowadays. Recent research shows that socio-cultural barriers to physical activity are mostly related to modern lifestyles. However, there is a lack of research on how social and group dynamics influence engagement in physical activity. Furthermore, there are few cross-cultural studies that have compared the social dynamics of (in)activity in different cultural settings. This paper therefore aims to analyse how social group dynamics influence physical activity and inactivity in informal social environments and whether physical activity is influenced by the socio-cultural settings. METHODS The paper presents the qualitative data collected within a covert participant observation study. Data was collected by keeping observational notes in order to record typical, regular patterns regarding physical (in)activity related behaviour of groups at an artificial open air swimming pool in Germany and a natural pond in Hawai'i. The data collection period was eight and a half months. Data was interpreted based on constant comparative analysis in order to identify most generative patterns in the field notes. RESULTS Group structures appear to play a significant role regarding the activity of the group members. In this study, we identified four key factors that influence group based physical activity: 1) Physical activity seems to be a group disturbing behaviour particularly in larger groups of adults; 2) Physical activity appears to be more functional and less joyful in adults than in children; 3) Group activity is influenced by (in)activity anchors, including 'domestication' of a group's site, obesity, and controlling parents. 4) Physical activity is to a certain extent socially contagious, particularly with regard to playful activities. CONCLUSIONS Successful promotion of physical activity should target the social structures of inactive individuals' groups. In this regard, one of the main problems is that fun and wellbeing, as very important targets of public health strategies for the adult population, appear not to be compatible with physical activity. Developing strategies to reframe physical activity rather as 'fun' and less as functional may be one way to engage inactive individuals in physical activity in leisure settings.
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Multi-ingredient, caffeine-containing dietary supplements: history, safety, and efficacy.
Gurley, BJ, Steelman, SC, Thomas, SL
Clinical therapeutics. 2015;(2):275-301
Abstract
PURPOSE Our objective was to review the history, safety, and efficacy of caffeine-containing dietary supplements in the United States and Canada. METHODS PubMed and Web of Science databases (1980-2014) were searched for articles related to the pharmacology, toxicology, and efficacy of caffeine-containing dietary supplements with an emphasis on Ephedra-containing supplements, Ephedra-free supplements, and energy drinks or shots. FINDINGS Among the first and most successful dietary supplements to be marketed in the United States were those containing Ephedra—combinations of ephedrine alkaloids, caffeine, and other phytochemicals. A decade after their inception, serious tolerability concerns prompted removal of Ephedra supplements from the US and Canadian markets. Ephedra-free products, however, quickly filled this void. Ephedra-free supplements typically contain multiple caffeine sources in conjunction with other botanical extracts whose purposes can often be puzzling and their pharmacologic properties difficult to predict. Ingestion of these products in the form of tablets, capsules, or other solid dosage forms as weight loss aids, exercise performance enhancers, or energy boosters have once again brought their tolerability and efficacy into question. In addition to Ephedra-free solid dosage forms, caffeine-containing energy drinks have gained a foothold in the world market along with concerns about their tolerability. IMPLICATIONS This review addresses some of the pharmacologic and pharmaceutical issues that distinguish caffeine-containing dietary supplement formulations from traditional caffeine-containing beverages. Such distinctions may account for the increasing tolerability concerns affiliated with these products.
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Children's implicit recall of junk food, alcohol and gambling sponsorship in Australian sport.
Bestman, A, Thomas, SL, Randle, M, Thomas, SD
BMC public health. 2015;:1022
Abstract
BACKGROUND In Australia, sport is saturated by the promotion of junk food, alcohol and gambling products. This is particularly evident on player jerseys. The effect of this advertising on children, who are exposed to these messages while watching sport, has not been thoroughly investigated. The aim of this research study was to investigate: (1) the extent to which children implicitly recalled shirt sponsors with the correct sporting team; (2) whether children associated some types of sponsors with certain sporting codes more than others; and (3) whether age of the children influenced the correct recall of sponsoring brands and teams. METHOD This experimental study conducted in New South Wales, Australia used projective techniques to measure the implicit recall of team sponsorship relationships of 85 children aged 5-12 years. Participants were asked to arrange two sets of magnets - one which contained sporting teams and one which contained brand logos - in the manner deemed most appropriate by them. Children were not given any prompts relating to sporting sponsorship relationships. RESULTS Three quarters (77 %) of the children were able to identify at least one correct shirt sponsor. Children associated alcohol and gambling brands more highly with the more popular sporting code, the National Rugby League compared to the Australian Football League sporting code. Results showed that age had an effect on number of shirt sponsors correctly recalled with 9-12 year olds being significantly more likely than 5-8 year olds to correctly identify team sponsors. CONCLUSIONS Given children's ability to implicitly recall shirt sponsors in a sporting context, Australian sporting codes should examine their current sponsorship relationships to reduce the number of unhealthy commodity shirt sponsors. While there is some regulation that protects children from the marketing of unhealthy commodity products, these findings suggest that children are still exposed to and recall these sponsorship relationships. Results suggest that the promotion of unhealthy commodity products during sporting matches is contributing to increased awareness amongst children of unhealthy commodity brands. Further investigation is required to examine the extent and impact of marketing initiatives during televised sporting matches on children.
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Falling threshold for treatment of borderline elevated thyrotropin levels-balancing benefits and risks: evidence from a large community-based study.
Taylor, PN, Iqbal, A, Minassian, C, Sayers, A, Draman, MS, Greenwood, R, Hamilton, W, Okosieme, O, Panicker, V, Thomas, SL, et al
JAMA internal medicine. 2014;(1):32-9
Abstract
IMPORTANCE Rates of thyroid hormone prescribing in the United States and the United Kingdom have increased substantially. If some of the increase is due to lowering the thyrotropin threshold for treatment, this may result in less benefit and greater harm. OBJECTIVE To define trends in thyrotropin levels at the initiation of levothyroxine sodium therapy and the risk of developing a suppressed thyrotropin level following treatment. DESIGN, SETTING, PARTICIPANTS, AND EXPOSURE Retrospective cohort study using data from the United Kingdom Clinical Practice Research Datalink. Among 52,298 individuals who received a prescription for levothyroxine between January 1, 2001, and October 30, 2009, we extracted data about the thyrotropin level before levothyroxine therapy initiation, clinical symptoms, and thyrotropin levels up to 5 years after levothyroxine was initiated. We excluded persons who had a history of hyperthyroidism, pituitary disease, or thyroid surgery; those who were taking thyroid-altering medication or if the levothyroxine prescription was related to pregnancy; and those who did not have a thyrotropin level measured within 3 months before the initiation of levothyroxine. MAIN OUTCOMES AND MEASURES The median thyrotropin level at the time of the index levothyroxine prescription, the odds of initiation of levothyroxine therapy at thyrotropin levels of 10.0 mIU/L or less, and the age-stratified odds of developing a low or suppressed thyrotropin level after levothyroxine therapy. RESULTS Between 2001 and 2009, the median thyrotropin level at the initiation of levothyroxine therapy fell from 8.7 to 7.9 mIU/L. The odds ratio for prescribing levothyroxine at thyrotropin levels of 10.0 mIU/L or less in 2009 compared with 2001 (adjusted for changes in population demographics) was 1.30 (95% CI, 1.19-1.42; P < .001). Older individuals and individuals with cardiac risk factors had higher odds of initiation of levothyroxine therapy with a thyrotropin level 10.0 mIU/L or less. At 5 years after levothyroxine initiation, 5.8% of individuals had a thyrotropin level of <0.1 mIU/L. Individuals with depression or tiredness at baseline had increased odds of developing a suppressed thyrotropin level, whereas individuals with cardiac risk factors (eg, atrial fibrillation, diabetes mellitus, hypertension, and raised lipid levels) did not. CONCLUSIONS AND RELEVANCE We observed a trend toward levothyroxine treatment of more marginal degrees of hypothyroidism and a substantial risk of developing a suppressed thyrotropin level following therapy. Large-scale prospective studies are required to assess the risk-benefit ratio of current practice.
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Local membrane deformations activate Ca2+-dependent K+ and anionic currents in intact human red blood cells.
Dyrda, A, Cytlak, U, Ciuraszkiewicz, A, Lipinska, A, Cueff, A, Bouyer, G, Egée, S, Bennekou, P, Lew, VL, Thomas, SL
PloS one. 2010;(2):e9447
Abstract
BACKGROUND The mechanical, rheological and shape properties of red blood cells are determined by their cortical cytoskeleton, evolutionarily optimized to provide the dynamic deformability required for flow through capillaries much narrower than the cell's diameter. The shear stress induced by such flow, as well as the local membrane deformations generated in certain pathological conditions, such as sickle cell anemia, have been shown to increase membrane permeability, based largely on experimentation with red cell suspensions. We attempted here the first measurements of membrane currents activated by a local and controlled membrane deformation in single red blood cells under on-cell patch clamp to define the nature of the stretch-activated currents. METHODOLOGY/PRINCIPAL FINDINGS The cell-attached configuration of the patch-clamp technique was used to allow recordings of single channel activity in intact red blood cells. Gigaohm seal formation was obtained with and without membrane deformation. Deformation was induced by the application of a negative pressure pulse of 10 mmHg for less than 5 s. Currents were only detected when the membrane was seen domed under negative pressure within the patch-pipette. K(+) and Cl(-) currents were strictly dependent on the presence of Ca(2+). The Ca(2+)-dependent currents were transient, with typical decay half-times of about 5-10 min, suggesting the spontaneous inactivation of a stretch-activated Ca(2+) permeability (PCa). These results indicate that local membrane deformations can transiently activate a Ca(2+) permeability pathway leading to increased [Ca(2+)](i), secondary activation of Ca(2+)-sensitive K(+) channels (Gardos channel, IK1, KCa3.1), and hyperpolarization-induced anion currents. CONCLUSIONS/SIGNIFICANCE The stretch-activated transient PCa observed here under local membrane deformation is a likely contributor to the Ca(2+)-mediated effects observed during the normal aging process of red blood cells, and to the increased Ca(2+) content of red cells in certain hereditary anemias such as thalassemia and sickle cell anemia.
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Being 'fat' in today's world: a qualitative study of the lived experiences of people with obesity in Australia.
Thomas, SL, Hyde, J, Karunaratne, A, Herbert, D, Komesaroff, PA
Health expectations : an international journal of public participation in health care and health policy. 2008;11(4):321-30
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Plain language summary
The obesity epidemic is one of the most pressing contemporary public health problems. The aim of this study was to develop a picture of both lived experiences of obesity and the impact of socio-cultural factors on obesity. The study adopted a qualitative research design (n=76) . A broad interview schedule was developed by the authors aimed at individuals from a broad range of backgrounds and experiences of obesity. Results indicate that: (a) the experiences of obesity are diverse but there are common themes. (b) people living with obesity have heard the messages but find it difficult to act upon them. (c) interventions should be tailored to address both individual and community needs. (d) there should be a different approach towards obesity interventions. Authors conclude that interventions should respond directly to the social and cultural dimensions of communities and clusters of individuals.
Abstract
OBJECTIVE To develop an in-depth picture of both lived experience of obesity and the impact of socio-cultural factors on people living with obesity. DESIGN Qualitative methodology, utilizing in-depth semi-structured interviews with a community sample of obese adults (body mass index >or=30). Community sampling methods were supplemented with purposive sampling techniques to ensure a diverse range of individuals were included. RESULTS Seventy-six individuals (aged 16-72) were interviewed. Most had struggled with their weight for most of their lives (n=45). Almost all had experienced stigma and discrimination in childhood (n=36), as adolescents (n=41) or as adults (n=72). About half stated that they had been humiliated by health professionals because of their weight. Participants felt an individual responsibility to lose weight, and many tried extreme forms of dieting to do so. Participants described an increasing culture of 'blame' against people living with obesity perpetuated by media and public health messages. Eighty percent said that they hated or disliked the word obesity and would rather be called fat or overweight. DISCUSSION AND CONCLUSION There are four key conclusions: (i) the experiences of obesity are diverse, but there are common themes, (ii) people living with obesity have heard the messages but find it difficult to act upon them, (iii) interventions should be tailored to address both individual and community needs and (iv) we need to rethink how to approach obesity interventions to ensure that avoid recapitulating damaging social stereotypes and exacerbating social inequalities.