A study was designed with two specific aims: (1) to assess the effect of soy bread, compared with wheat bread, on markers of bone metabolism and cardiovascular health, and (2) to evaluate whether soy bread consumption affects the metabolism of phytoestrogens. To answer Aim 1, a double-blind randomized crossover trial was conducted. Individuals with an ability to metabolize a specific isoflavone, daidzein, consumed 3 slices of bread (either soy or wheat) daily over a 12-week period. After a 4-week wash-out period, subjects consumed 3 slices/day of the other type of bread. Markers of bone metabolism and cardiovascular health were evaluated before and after each time period. To answer Aim 2, individuals who did not metabolize daidzein at baseline entered a double-blind randomized trial of soy bread with or without fructooligosaccharide (a type of dietary fiber) over an 8-week period. Subjects were evaluated regarding their ability to metabolize daidzein to equol.