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Effects of vitamin E, vitamin C and polyphenols on the rate of blood pressure variation: results of two randomised controlled trials
- Jonathan M. Hodgson, Kevin D. Croft, Richard J. Woodman, Ian B. Puddey, Catherine P. Bondonno, Jason H. Y. Wu, Lawrence J. Beilin, Elena V. Lukoshkova, Geoffrey A. Head, Natalie C. Ward
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- Journal:
- British Journal of Nutrition / Volume 112 / Issue 9 / 14 November 2014
- Published online by Cambridge University Press:
- 19 September 2014, pp. 1551-1561
- Print publication:
- 14 November 2014
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High blood pressure (BP) variability, which may be an important determinant of hypertensive end-organ damage, is emerging as an important predictor of cardiovascular health. Dietary antioxidants can influence BP, but their effects on variability are yet to be investigated. The aim of the present study was to assess the effects of vitamin E, vitamin C and polyphenols on the rate of daytime and night-time ambulatory BP variation. To assess these effects, two randomised, double-blind, placebo-controlled trials were performed. In the first trial (vitamin E), fifty-eight individuals with type 2 diabetes were given 500 mg/d of RRR-α-tocopherol, 500 mg/d of mixed tocopherols or placebo for 6 weeks. In the second trial (vitamin C–polyphenols), sixty-nine treated hypertensive individuals were given 500 mg/d of vitamin C, 1000 mg/d of grape-seed polyphenols, both vitamin C and polyphenols, or neither (placebo) for 6 weeks. At baseline and at the end of the 6-week intervention, 24 h ambulatory BP and rate of measurement-to-measurement BP variation were assessed. Compared with placebo, treatment with α-tocopherol, mixed tocopherols, vitamin C and polyphenols did not significantly alter the rate of daytime or night-time systolic BP, diastolic BP or pulse pressure variation (P>0·05). Treatment with the vitamin C and polyphenol combination resulted in higher BP variation: the rate of night-time systolic BP variation (P= 0·022) and pulse pressure variation (P= 0·0036) were higher and the rate of daytime systolic BP variation was higher (P= 0·056). Vitamin E, vitamin C or grape-seed polyphenols did not significantly alter the rate of BP variation. However, the increase in the rate of BP variation suggests that the combination of high doses of vitamin C and polyphenols could be detrimental to treated hypertensive individuals.
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- By Waiel Almoustadi, Brian J. Anderson, David B. Auyong, Michael Avidan, Michael J. Avram, Roland J. Bainton, Jeffrey R. Balser, Juliana Barr, W. Scott Beattie, Manfred Blobner, T. Andrew Bowdle, Walter A. Boyle, Eugene B. Campbell, Laura F. Cavallone, Mario Cibelli, C. Michael Crowder, Ola Dale, M. Frances Davies, Mark Dershwitz, George Despotis, Clifford S. Deutschman, Brian S. Donahue, Marcel E. Durieux, Thomas J. Ebert, Talmage D. Egan, Helge Eilers, E. Wesley Ely, Charles W. Emala, Alex S. Evers, Heidrun Fink, Pierre Foëx, Stuart A. Forman, Helen F. Galley, Josephine M. Garcia-Ferrer, Robert W. Gereau, Tony Gin, David Glick, B. Joseph Guglielmo, Dhanesh K. Gupta, Howard B. Gutstein, Robert G. Hahn, Greg B. Hammer, Brian P. Head, Helen Higham, Laureen Hill, Kirk Hogan, Charles W. Hogue, Christopher G. Hughes, Eric Jacobsohn, Roger A. Johns, Dean R. Jones, Max Kelz, Evan D. Kharasch, Ellen W. King, W. Andrew Kofke, Tom C. Krejcie, Richard M. Langford, H. T. Lee, Isobel Lever, Jerrold H. Levy, J. Lance Lichtor, Larry Lindenbaum, Hung Pin Liu, Geoff Lockwood, Alex Macario, Conan MacDougall, M. B. MacIver, Aman Mahajan, Nándor Marczin, J. A. Jeevendra Martyn, George A. Mashour, Mervyn Maze, Thomas McDowell, Stuart McGrane, Berend Mets, Patrick Meybohm, Charles F. Minto, Jonathan Moss, Mohamed Naguib, Istvan Nagy, Nick Oliver, Paul S. Pagel, Pratik P. Pandharipande, Piyush Patel, Andrew J. Patterson, Robert A. Pearce, Ronald G. Pearl, Misha Perouansky, Kristof Racz, Chinniampalayam Rajamohan, Nilesh Randive, Imre Redai, Stephen Robinson, Richard W. Rosenquist, Carl E. Rosow, Uwe Rudolph, Francis V. Salinas, Robert D. Sanders, Sunita Sastry, Michael Schäfer, Jens Scholz, Thomas W. Schnider, Mark A. Schumacher, John W. Sear, Frédérique S. Servin, Jeffrey H. Silverstein, Tom De Smet, Martin Smith, Joe Henry Steinbach, Markus Steinfath, David F. Stowe, Gary R. Strichartz, Michel M. R. F. Struys, Isao Tsuneyoshi, Robert A. Veselis, Arthur Wallace, Robert P. Walt, David C. Warltier, Nigel R. Webster, Jeanine Wiener-Kronish, Troy Wildes, Paul Wischmeyer, Ling-Gang Wu, Stephen Yang
- Edited by Alex S. Evers, Washington University School of Medicine, St Louis, Mervyn Maze, University of California, San Francisco, Evan D. Kharasch, Washington University School of Medicine, St Louis
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- Book:
- Anesthetic Pharmacology
- Published online:
- 11 April 2011
- Print publication:
- 10 March 2011, pp viii-xiv
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Assessment of isoflavonoid concentrations in Australian bovine milk samples
- ROGER A. KING, MARK M. MANO, RICHARD J. HEAD
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- Journal:
- Journal of Dairy Research / Volume 65 / Issue 3 / August 1998
- Published online by Cambridge University Press:
- 01 August 1998, pp. 479-489
- Print publication:
- August 1998
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There is considerable interest in the possibility that diet-derived isoflavonoids may help in protection against a number of chronic diseases common in Western society. Based on animal studies, however, concerns have been raised that consumption of isoflavonoids by infants and young children may be undesirable. Clover contains isoflavonoids and therefore may represent, via milk, a source of isoflavonoids in the human diet. In this study the concentrations of daidzein (7, 4′-dihydroxyisoflavone), genistein (5, 7, 4′-trihydroxyisoflavone) and equol (7-hydroxy-(4′-hydroxyphenyl)chroman) were measured using HPLC in cows' milk samples obtained from 76 farms in three Australian states. In addition, concentrations were measured in samples collected from one South Australian factory both before and after pasteurization. Concentrations in all samples were found to be extremely low. The mean daidzein concentration was <5 ng/ml. Mean genistein concentrations ranged from just detectable (∼2 ng/ml) in Victorian samples collected during summer to 20-30 ng/ml in samples from all states collected during spring when isoflavonoid-containing clover is most dominant in pasture. Mean equol concentrations ranged from 45±10 ng/ml in Victorian farm samples collected during summer to 293±52 ng/ml in Western Australian samples collected in spring. The mean concentrations of genistein and equol in post-pasteurization samples collected in spring were approximately double those for samples collected in autumn. Pasteurization had no effect on isoflavonoid concentrations. We conclude that the concentrations of isoflavonoids in Australian cows' milk are low and are therefore unlikely to have any pronounced biological effects in human consumers.