Margaret (name changed) had lived in rural Kentucky her entire 78-year life when the words started disappearing. Simple ones first – the name of her neighbour's dog, the street where her daughter lived. Then bigger chunks of her world began slipping away, piece by piece, until she couldn't remember her late husband's face.
What Margaret didn't know was that her Kentucky address had made her 25% more likely to develop dementia than if she'd lived just a few hundred miles north-east. A landmark study tracking over one million American veterans has revealed something troubling: where you live dramatically affects your chances of losing your mind.
