100,000 people, 250 biomarkers, and the quest for good health

Researchers seek the keys to wellness in a project of staggering ambition. Intensely monitoring healthy individuals could make them less well, not more. Take today's screenings for prostate cancer, which often flag benign lesions and slow-growing tumors that will never become life threatening. Worried that patients were undergoing unnecessary surgeries, medical groups recently scaled back screening recommendations. The more measurements you take, the more likely you are to find something wrong.