OBJECTIVE: To study dietary intake and serum concentrations of isoflavones in order to provide relative validation of isoflavone intake estimates from the Scottish Collaborative Group - Food-Frequency Questionnaire (SCG-FFQ). DESIGN: Validation study. SETTING: Southern Scotland. METHOD: Dietary intake of isoflavones was estimated using the semiquantitative SCG-FFQ and rank correlation and Kappa statistics were used for the relative validation of intakes against serum isoflavone concentrations in 203 male participants who were population controls in a case-control study of diet and prostate cancer. RESULTS: The median intake of isoflavones (daidzein and genistein) was 1.0mg/day (l-QR 0.6-1.8). The median serum concentration of genistein was 33.79 nmol/l (I-QR 14.12-64.93), nearly twice that of daidzein (18.00 nmol/l, I-QR 8.26-29.45). Equol was detected in 49% of subjects; in these subjects the median was 0.67 nmol/l (I-QR 0.34-1.51). Isoflavone intake was significantly correlated with serum concentrations of daidzein (p = 0.24, P = 0.001), genistein (p = 0.26, P < 0.001) and total isoflavonoids (sum of daidzein, genistein and equol) ( p = 0.27, P < 0.001). Whereas values for weighted Kappa ranged from 0.16 (P = 0.002) for daidzein and equol combined to 0.22 (P < 0.001) for genistein. CONCLUSIONS: These results demonstrate the suitability of the SCG-FFQ to rank usual isoflavone intakes in older Scottish men, a population observed to have low consumption of soy foods.
OBJECTIVE: To study dietary intake and serum concentrations of isoflavones in order to provide relative validation of isoflavone intake estimates from the Scottish Collaborative Group - Food-Frequency Questionnaire (SCG-FFQ). DESIGN: Validation study. SETTING: Southern Scotland. METHOD: Dietary intake of isoflavones was estimated using the semiquantitative SCG-FFQ and rank correlation and Kappa statistics were used for the relative validation of intakes against serum isoflavone concentrations in 203 male participants who were population controls in a case-control study of diet and prostate cancer. RESULTS: The median intake of isoflavones (daidzein and genistein) was 1.0mg/day (l-QR 0.6-1.8). The median serum concentration of genistein was 33.79 nmol/l (I-QR 14.12-64.93), nearly twice that of daidzein (18.00 nmol/l, I-QR 8.26-29.45). Equol was detected in 49% of subjects; in these subjects the median was 0.67 nmol/l (I-QR 0.34-1.51). Isoflavone intake was significantly correlated with serum concentrations of daidzein (p = 0.24, P = 0.001), genistein (p = 0.26, P < 0.001) and total isoflavonoids (sum of daidzein, genistein and equol) ( p = 0.27, P < 0.001). Whereas values for weighted Kappa ranged from 0.16 (P = 0.002) for daidzein and equol combined to 0.22 (P < 0.001) for genistein. CONCLUSIONS: These results demonstrate the suitability of the SCG-FFQ to rank usual isoflavone intakes in older Scottish men, a population observed to have low consumption of soy foods.
Authors: Suzan L Carmichael; Mary E Cogswell; Chen Ma; Amparo Gonzalez-Feliciano; Richard S Olney; Adolfo Correa; Gary M Shaw Journal: Am J Epidemiol Date: 2013-06-09 Impact factor: 4.897
Authors: Jozef Hooson Jzh; Jayne Hutchinson Jyh; Marisol Warthon-Medina; Neil Hancock; Katharine Greathead; Bethany Knowles; Elisa Vargas-Garcia; Lauren E Gibson; Linda A Bush; Barrie Margetts; Sian Robinson; Andy Ness; Nisreen A Alwan; Petra A Wark; Mark Roe; Paul Finglas; Toni Steer; Polly Page; Laura Johnson; Katharine Roberts; Birdem Amoutzopoulos; Victoria J Burley; Darren C Greenwood; Janet E Cade Journal: Crit Rev Food Sci Nutr Date: 2019-03-18 Impact factor: 11.176