(PTFS08-04-25) Effect of Fermented Soy on Cognitive Function in Older Adults: Outcomes of a Randomized, Controlled, Clinical Trial

Objectives: This study aimed to investigate the effects of daily consumption of fermented soy on cognition in older adults.

Methods: In a 12-week randomized, double-blind, placebo-controlled trial, 61 healthy older men and postmenopausal women supplemented their habitual diet with either fermented soy powder or a whey-based placebo powder. Daily intake of the fermented soy intervention contained 9.4 g protein and 36.3 mg isoflavones, and the placebo, 8.5 g protein and 0 mg isoflavones. A battery of neuropsychological tests was administered to participants at baseline and week 12 to examine effects in the cognitive domains of memory, verbal fluency, processing speed, and executive function. Test scores were transformed into percent of maximum possible, then averaged within each cognitive domain to calculate domain-specific scores and averaged across all tests for a global cognition score. Between-group mean changes in test scores from baseline to week 12 for global cognition and cognitive domains were analyzed using analysis of covariance, adjusted for sex and baseline scores.

Results: Among the 48 participants who completed the study (12 males/36 females, mean ± SD age 74.0 ± 5.0), mean change in memory scores for between-group effects from baseline to week 12 was significantly better (p = 0.037) with daily fermented soy intake [mean (95% CI): 1.9 (-1.0, 5.8)] compared to placebo: 1.4 (-3.0, 5.8). There were no significant differences for any of the other cognitive domains or global cognition. Post hoc analyses showed between-group effects of fermented soy to be strongest in women 70 years and older, with significantly more improvement in memory scores (p = 0.049) for the fermented soy group: [mean (95% CI): 8.5 (5.1, 11.9)] compared with placebo: 2.1 (-1.8, 5.8) . Global cognition scores for women 70 and older also showed significantly more improvement (p = 0.023) in the fermented soy group [mean (95% CI): 2.9 (1.5, 4.2)] compared to placebo: 0.0 (-1.5, 1.5).

Conclusions: Daily intake of fermented soy for 12 weeks resulted in improved memory performance in older adults, especially women 70 and older, compared with placebo. These findings suggest that fermented soy may play a valuable role in slowing age-related cognitive decline.

Funding Sources: Beso Biological Research, Inc., Diamond Bar, CA, USA