Figure 2.

Urinary isoflavone (sum of daidzein, genistein, formononetin and biochanin A) excretion at baseline, midway, and at the end of the study, excluding samples with < 70% or > 110% para-amino benzoic acid recovery. Error bars represent ± standard error of the mean. Numbers at each evaluation were as follows: baseline, 66 and 72 in the isoflavone and placebo groups, respectively; 6 months, 70 and 73; and 12 months, 76 and 79. The difference in isoflavone excretion between treatment groups was not statistically significant at baseline (P = 0.23), but differences between treatment groups at 6 and 12 months were highly significant (P < 0.001 and P < 0.001).