“…Importantly, the isoflavone content of these over-the-counter tablets can vary widely between manufacturers (Setchell et al, 2001); making it difficult to discern what, if any, active ingredients may aide in healthy cognitive aging. For instance, reports of the effects of several commercially available dietary soy-based supplements (with mixed isoflavone contents/concentrations) on learning and memory processes from randomized controlled studies in aging women vary, reporting no effect (Basaria et al, 2009; Fournier et al, 2007; Henderson et al, 2012; Ho et al, 2007; Kreijkamp-Kaspers et al, 2004), some improvement (Casini et al, 2006; Duffy et al, 2003; File et al, 2005; Gleason et al, 2009; Kritz-Silverstein et al, 2003; Santos-Galduroz et al, 2010), or even an impairment (Kritz-Silverstein et al, 2003). In addition to isoflavone composition, methodological differences in age at the time of treatment, previous HRT use, cognitive domain tested, and length of treatment likely contribute to the conflicting findings among published reports (see also Sumien et al, 2013).…”