At 90, Thelma Johnson works out at a health club three times a week. She and her 87-year-old husband walk at least a mile on the other days. The couple recently went on a cruise to Alaska and they like to organize outings with friends.The Johnsons may seem remarkable, but they’re not much of an anomaly in Loma Linda, California. There is something big happening in this small town 60 miles east o
