Effects of Green Tea Catechins and Theanine on Preventing Influenza Infection among Healthcare Workers: A Randomized Controlled Trial

<p>Abstract</p> <p>Background</p> <p>Experimental studies have revealed that green tea catechins and theanine prevent influenza infection, while the clinical evidence has been inconclusive. This study was conducted to determine whether taking green tea catechins and theanine can clinically prevent influenza infection.</p> <p>Methods</p> <p><b>Design, Setting, and Participants</b>: A randomized, double-blind, placebo-controlled trial of 200 healthcare workers conducted for 5 months from November 9, 2009 to April 8, 2010 in three healthcare facilities for the elderly in Higashimurayama, Japan.</p> <p><b>Interventions</b>: The catechin/theanine group received capsules including green tea catechins (378 mg/day) and theanine (210 mg/day). The control group received placebo.</p> <p><b>Main Outcome Measures</b>: The primary outcome was the incidence of clinically defined influenza infection. Secondary outcomes were (1) laboratory-confirmed influenza with viral antigen measured by immunochromatographic assay and (2) the time for which the patient was free from clinically defined influenza infection, i.e., the period between the start of intervention and the first diagnosis of influenza infection, based on clinically defined influenza infection.</p> <p>Results</p> <p>Eligible healthcare workers (n = 197) were enrolled and randomly assigned to an intervention; 98 were allocated to receive catechin/theanine capsules and 99 to placebo. The incidence of clinically defined influenza infection was significantly lower in the catechin/theanine group (4 participants; 4.1%) compared with the placebo group (13 participants; 13.1%) (adjusted OR, 0.25; 95% CI, 0.07 to 0.76, <it>P </it>= 0.022). The incidence of laboratory-confirmed influenza infection was also lower in the catechin/theanine group (1 participant; 1.0%) than in the placebo group (5 participants; 5.1%), but this difference was not significant (adjusted OR, 0.17; 95% CI, 0.01 to 1.10; <it>P </it>= 0.112). The time for which the patient was free from clinically defined influenza infection was significantly different between the two groups (adjusted HR, 0.27; 95% CI, 0.09 to 0.84; <it>P </it>= 0.023).</p> <p>Conclusions</p> <p>Among healthcare workers for the elderly, taking green tea catechins and theanine may be effective prophylaxis for influenza infection.</p> <p>Trial Registration</p> <p>ClinicalTrials (NCT): <a href="http://www.clinicaltrials.gov/ct2/show/NCT01008020">NCT01008020</a></p

On the pulmonary toxicity of oxygen : III. The induction of oxygen dependency by oxygen use

Author Posting. © The Author(s), 2010. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Experimental and Molecular Pathology 89 (2010): 36-45, doi:10.1016/j.yexmp.2010.05.004.Oxygen is central to the development of neonatal lung injury. The increase in oxygen exposure of the neonatal lung during the onset of extrauterine air breathing is an order of magnitude, from a range of 10-12 to 110-120 Torr. The contributions of oxygen and the volume and pressure relationships of ventilatory support to lung injury are not easily distinguished in the clinical setting. Sequential changes in inspired air or 100% oxygen were studied in 536 newborn rabbits without ventilatory support. Bilateral cervical vagotomies (BCV) were performed at 24 hours post natal to induce ventilatory distress which eventuates in hyaline membrane disease. The sequences applied yielded evidence for an induced state of oxygen dependency from oxygen use which was reflected in differences in survival and the extent of pulmonary injury. The median survival for animals kept in air throughout was 3 hours. Oxygen before vagotomy or during the first 3 hours afterwards extended the survival significantly but produced more extensive, more severe, and more rapid lung lesions. Returning animals to air after prior oxygen exposure reduced the number of survivors past 10 hours and shortened the maximum survival in those groups. These features indicate the development of a dependency of the defense mechanisms on the availability of oxygen at the higher level for metabolic and possibly other aspects of the pulmonary and systemic response to injury, beyond the usual physiological need. Subset analysis revealed additive and latent effects of oxygen and demonstrated a remarkable rapidity in onset of severe lesions under some circumstances, illustrating the toxicity of oxygen per se.John A. Hartford Foundation, New York, N.Y. 10022-171

Role of the small intestine, colon and microbiota in determining the metabolic fate of polyphenols

(Poly)phenols are a large group of compounds, found in food, beverages, dietary supplements and herbal medicines. Owing to their biological activities, absorption and metabolism of the most abundant compounds in humans are well understood. Both the chemical structure of the phenolic moiety and any attached chemical groups define whether the polyphenol is absorbed in the small intestine, or reaches the colon and is subject to extensive catabolism by colonic microbiota. Untransformed substrates may be absorbed, appearing in plasma primarily as methylated, sulfated and glucuronidated derivatives, with in some cases the unchanged substrate. Many of the catabolites are well absorbed from the colon and appear in the plasma either similarly conjugated, or as glycine conjugates, or in some cases unchanged. Although many (poly)phenol catabolites have been identified in human plasma and / or urine, the pathways from substrate to final catabolite, and the species of bacteria and enzymes involved, are still scarcely reported. While it is clear that the composition of the human gut microbiota can be modulated in vivo by supplementation with some (poly)phenol-rich commodities, such modulation is definitely not an inevitable consequence of supplementation, it depends on the treatment, length of time and on the individual metabotype, and it is not clear whether the modulation is sustained when supplementation ceases. Some catabolites have been recorded in plasma of volunteers at concentrations similar to those shown to be effective in in vitro studies suggesting that some benefit may be achieved in vivo by diets yielding such catabolites