Subjective cognitive difficulties are common in midlife and later life, and flavonoid-rich foods may support everyday cognitive function. Tartary buckwheat (Fagopyrum tataricum) sprouts are rich in rutin and other flavonoids, but their cognitive effects have not been tested in humans. In this randomized, double-blind, placebo-controlled trial, US adults with self-reported cognitive difficulties received 18 g per day of Himalayan Tartary buckwheat (HTB) sprout powder or matched placebo for 12 weeks. Of 848 randomized participants, 662 were analyzed.