For generations, older adults have reached for supplement bottles as quiet acts of self-care, trusting that products lining pharmacy shelves with promises of memory and mental sharpness were, at minimum, harmless. Now, a growing wave of scientific concern is unsettling that trust — researchers are finding that popular brain-health supplements may carry risks specific to aging cognition, risks that were never properly examined because the elderly were never properly studied. The gap between what is marketed and what is known has become too wide to ignore, and the reckoning, long overdue, has be