scholarly journals Genistein Aglycone Does Not Affect Thyroid Function: Results from a Three-Year, Randomized, Double-Blind, Placebo-Controlled Trial

2010 ◽  
Vol 95 (6) ◽  
pp. 3067-3072 ◽  
Author(s):  
Alessandra Bitto ◽  
Francesca Polito ◽  
Marco Atteritano ◽  
Domenica Altavilla ◽  
Susanna Mazzaferro ◽  
...  

Abstract Context and Objective: Genistein aglycone positively affects postmenopausal symptoms. However, questions about its long-term safety on the thyroid gland still remain. Design: The parent study was a randomized, double-blind, placebo-controlled trial involving 389 osteopenic, postmenopausal women for 24 months. A subcohort (138 patients) continued therapy for an additional year. Setting: Patients received ambulatory care. Patients and Interventions: Participants received 54 mg of genistein aglycone daily (n = 71) or placebo (n = 67), plus calcium and vitamin D3 at therapeutic doses. Circulating thyroid hormones (TSH, free T3, free T4) and autoantibodies (thyroid peroxidase, thyroglobulin, and thyroid microsomal antigen) were assessed in 40 genistein and 37 placebo subjects who completed 3 yr. Thyroid hormone receptor (THRα and THRβ) and retinoid receptor (RARα, RARγ, and RXRα) expression from peripheral blood monocytes was also evaluated at baseline, 12, 24, and 36 months in all 3-yr completers. Results: Genistein administration over 3 yr did not affect serum thyroid hormones or autoantibodies. In addition, there were no differences in THRα, THRβ, RARα, RARγ, or RXRα mRNA expression between groups. Conclusion: These data suggest that genistein aglycone intake does not significantly increase the risk of clinical or subclinical hypothyroidism at the dose of 54 mg/d.

1995 ◽  
Vol 89 (6) ◽  
pp. 637-642 ◽  
Author(s):  
Oliviero Olivieri ◽  
Domenico Girelli ◽  
Margherita Azzini ◽  
Anna Maria Stanzial ◽  
Carla Russo ◽  
...  

1. Iodothyronine 5′-deiodinase, which is mainly responsible for peripheral triiodothyronine (T3) production, has recently been demonstrated to be a selenium-containing enzyme. In the elderly, reduced peripheral conversion of thyroxine (T4) to T3 and overt hypothyroidism are frequently observed. 2. We measured serum selenium and erythrocyte glutathione peroxidase (as indices of selenium status), thyroid hormones and thyroid-stimulating hormone in 109 healthy euthyroid subjects (52 women, 57 men), carefully selected to exclude abnormally low thyroid hormone levels induced by acute or chronic diseases or calorie restriction. The subjects were subdivided into three age groups. To avoid conditions of undernutrition or malnutrition, dietary records were obtained for a sample of 24 subjects, randomly selected and representative of the whole population for age and sex. 3. In order to properly assess the influence of selenium status on iodothyronine 5′-deiodinase type I activity, a double-blind placebo-controlled trial was also carried out on 36 elderly subjects, resident at a privately owned nursing home. 4. In the free-living population, a progressive reduction of the T3/T4 ratio (due to increased T4 levels) and of selenium and erythrocyte glutathione peroxidase activity was observed with advancing age. A highly significant linear correlation between T4, T3/T4 and selenium was observed in the population as a whole (for T4, R = −0.312, P < 0.002; for T3/T4 ratio, R = 0.32, P < 0.01) and in older subjects (for T4, R = −0.40, P < 0.05; for T3/T4 ratio, R = 0.54, P < 0.002). 5. The main result of the double-blind placebo-controlled trial was a significant improvement of selenium indices and a decrease in the T4 level in selenium-treated subjects; serum selenium, erythrocyte glutathione peroxidase activity and thyroid hormones did not change in placebo-treated subjects. 6. We concluded that selenium status influences thyroid hormones in the elderly, mainly modulating T4 levels.


1997 ◽  
Vol 27 (8) ◽  
pp. 860-867 ◽  
Author(s):  
V.A. VARNEY ◽  
J. EDWARDS ◽  
K. TABBAH ◽  
H. BREWSTER ◽  
G. MAVROLEON ◽  
...  

2001 ◽  
Vol 120 (5) ◽  
pp. A384-A384
Author(s):  
L MOLLISON ◽  
L TOTTEN ◽  
C HOVELL ◽  
K THAYNE ◽  
C CONNELLY ◽  
...  

2007 ◽  
Vol 177 (4S) ◽  
pp. 14-15
Author(s):  
Brian J. DeCastro ◽  
Jack R. Walter ◽  
Leah P. McMann ◽  
Andrew C. Peterson

2012 ◽  
Vol 82 (4) ◽  
pp. 260-266 ◽  
Author(s):  
Salah E. Gariballa ◽  
Sarah J. Forster ◽  
Hilary J. Powers

Background: Although a number of studies have reported raised total plasma homocysteine (tHcy) concentrations in free-living older people, there are no data on homocysteine response to a mixed nutrient supplement in older patients. A raised plasma homocysteine concentration in older patients is partly a reflection of their co-morbidity, including impaired renal function, and there is uncertainty about the extent to which dietary interventions can improve plasma tHcy. Aim: To determine the plasma tHcy response to dietary supplements during acute illness. Methods: Two-hundred and thirty-six hospitalized, acutely ill older patients, who were part of a randomized double-blind placebo-controlled trial, were assigned to receive a daily oral nutritional supplement drink containing 1.3 mg of vitamin B2, 1.4 mg of vitamin B6, 1.5 μg of B12, 200 μg of folic acid, or a placebo, for 6 weeks. Outcome measures were plasma tHcy concentration at baseline, 6 weeks, and 6 months. Results: The mean plasma tHcy concentration fell among patients given the supplements (mean difference 4.1 µmol/L [95 % C.I, 0.14 to 8.03), p = 0.043], but tHcy concentration increased between 6 weeks and 6 months, after patients stopped taking the supplements [mean difference -2.0 µmol/L (95 % C.I, -03.9 to -0.18), p = 0.033]. About 46 % of patients in the placebo group and 55 % of patients in the supplement group had hyperhomocysteinemia (>14 µmol/L) at baseline compared with 45 % and 29 % at the end of the treatment period. Conclusions: A mixed nutrient supplement containing physiological amounts of B vitamins significantly reduced plasma tHcy concentrations in older patients recovering from acute illness.


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