An apple a day keeps the doctor away, but your morning java might keep you sharp. While the scientific opinions on life’s greatest pleasures — coffee , alcohol, dark chocolate — seem to be in a constant state of flux, researchers in Cambridge, Massachusetts, this week are giving your caffeine addiction the thumbs-up, saying that it might actually be good for long-term cognitive function. A new study analyzing decades of research — featuring a whopping 130,000 participants — found that daily