scholarly journals Acute effects of tea on fasting and non-fasting plasma total homocysteine concentrations in human subjects

2007 ◽  
Vol 97 (5) ◽  
pp. 842-846 ◽  
Author(s):  
Jonathan M. Hodgson ◽  
Ian B. Puddey ◽  
Frank M. van Bockxmeer ◽  
Valerie Burke

Plasma total homocysteine concentrations (tHcy) are a putative risk factor for CVD. Tea is a rich dietary source of polyphenols and caffeine, both of which may raise tHcy. However, it is possible that much of any effect is transitory and may be influenced by the consumption of food. Our objective was to investigate the acute effect of tea, at a dose representative of ordinary population intakes, on tHcy and to determine whether consumption of a meal influences the magnitude of any effect. Measurements of tHcy were performed in twenty participants at baseline and 3.5 h after drinking three cups of black tea or hot water (consumed at time 0, 1.5 and 3 h) with and without a meal: a total of four treatments administered in random order. Drinking tea resulted in an acute increase in tHcy (0·30 (95 % CI 0·04, 0·56) μmol/l, P = 0·022). The meal resulted in an acute decrease in tHcy ( − 0·42 (95 % CI − 0·68, − 0·16) μmol/l, P = 0·002). There was no interaction between tea and meal on tHcy (P = 0·40); that is, the effect of tea on tHcy was not different in the fasting and non-fasting state. Our results suggest that drinking black tea can cause a small acute increase in tHcy and that this effect is not enhanced in the non-fasting state. Given that results of population studies have generally shown a negative association between tea intake and tHcy, the significance of these findings to CVD risk remains uncertain.

2002 ◽  
Vol 48 (9) ◽  
pp. 1383-1389 ◽  
Author(s):  
Karin JA Lievers ◽  
Lydia A Afman ◽  
Leo AJ Kluijtmans ◽  
Godfried HJ Boers ◽  
Petra Verhoef ◽  
...  

Abstract Background: Hyperhomocysteinemia is an independent risk factor for cardiovascular disease (CVD). Intracellular vitamin B12 deficiency may lead to increased plasma total homocysteine (tHcy) concentrations and because transcobalamin (TC) is the plasma transporter that delivers vitamin B12 to cells, genetic variation in the TC gene may affect intracellular vitamin B12 availability and, consequently, tHcy concentrations. Methods: We examined five sequence variants, i.e., I23V, G94S, P259R, S348F, and R399Q, in the TC gene as possible determinants of tHcy and, concordantly, as possible risk factors for CVD in 190 vascular disease patients and 601 controls. We also studied potential effect-modification of vitamin B12 by genotype. Results: In individuals with high vitamin B12, 259PP individuals had lower tHcy concentrations than 259PR and 259RR individuals. Homozygous 23VV individuals had lower fasting tHcy concentrations than their 23IV and 23II peers. None of the genotypes defined by the three other sequence variants showed an association with tHcy concentrations, nor was any TC genotype associated with an increased CVD risk. Conclusions: In individuals in the highest quartile of the vitamin B12 distribution (>299 pmol/L), tHcy concentrations are lower in 259PP homozygotes than in 259PR and 259RR individuals. Therefore, 259PP individuals, who represent >25% of the general population, may be more susceptible to reduction of plasma tHcy concentrations by increasing the vitamin B12 status.


2003 ◽  
Vol 77 (4) ◽  
pp. 907-911 ◽  
Author(s):  
Jonathan M Hodgson ◽  
Valerie Burke ◽  
Lawrence J Beilin ◽  
Kevin D Croft ◽  
Ian B Puddey

Author(s):  
Per Magne Ueland ◽  
Pål I. Holm ◽  
Steinar Hustad

AbstractBetaine serves as a methyl donor in a reaction converting homocysteine to methionine, catalysed by the enzyme betaine-homocysteine methyltransferase. It has been used for years to lower the concentration of plasma total homocysteine (tHcy) in patients with homocystinuria, and has recently been shown to reduce fasting and in particular post-methionine load (PML) tHcy in healthy subjects.Betaine exists in plasma at concentrations of about 30μmol/L; it varies 10-fold (from 9 to 90μmol/L) between individuals, but the intra-individual variability is small. Major determinants are choline, dimethylglycine and folate in plasma, folic acid intake and gender.Recent studies have demonstrated that plasma betaine is a stronger determinant of PML tHcy than are vitamin BTo conclude, betaine status is a component of an individual's biochemical make-up with ramifications to one-carbon metabolism. Betaine status should be investigated in pathologies related to altered metabolism of homocysteine and folate, including cardiovascular disease, cancer and neural tube defects.


2003 ◽  
Vol 168 (1) ◽  
pp. 139-146 ◽  
Author(s):  
Erik J. Giltay ◽  
Petra Verhoef ◽  
Louis J.G. Gooren ◽  
Johanna M. Geleijnse ◽  
Evert G. Schouten ◽  
...  

2018 ◽  
Vol 02 (05) ◽  
pp. E142-E147 ◽  
Author(s):  
Masatoshi Nakamura ◽  
Ryo Hirabayashi ◽  
Shuhei Ohya ◽  
Takafumi Aoki ◽  
Daichi Suzuki ◽  
...  

AbstractThis study aimed to clarify the acute effect of static stretching (SS) with superficial cooling on dorsiflexion range of motion (DF ROM) and muscle stiffness. Sixteen healthy males participated in the cooling condition and a control condition in a random order. The DF ROM and the shear elastic modulus of medial gastrocnemius (MG) in the dominant leg were measured during passive dorsiflexion. All measurements were performed prior to (PRE) and immediately after 20 min of cooling or rested for 20 min (POST), followed by 2 min SS (POST SS). In cooling condition, DF ROM at POST and POST SS were significantly higher than that at PRE and DF ROM at POST SS was significantly higher than that at POST. In addition, the shear elastic modulus at POST was significantly higher than that at PRE and the shear elastic modulus at POST SS was significantly lower than those at PRE and POST. However, there were no significant differences in the percentage changes between PRE and POST SS between the cooling and control conditions. Our results showed that effects of SS with superficial cooling on increases in ROM and decrease in muscle stiffness were no more beneficial than those of SS alone.


2005 ◽  
Vol 15 (2) ◽  
pp. 134-139 ◽  
Author(s):  
J.T. Real ◽  
A. Merchante ◽  
J.L. Gómez ◽  
F.J. Chaves ◽  
J.F. Ascaso ◽  
...  

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