As health-food stores go, the Hardened Artery is as steady as any. Perusing its pricey nutrients last week in quest of some vitalizing herb or root to flush out a family of free radicals that had built their nest in my chassis, I came vis-à-vis a bottle of red fluid nestled like a krait between the ginseng and the echinacea and sporting the Ray Bradburyish title “Brainiac.” Plucked from its niche, it claimed to be a thirst quencher chockablock with gingko biloba and sundry antioxidants reputed to enhance memory.