Every week, Dr. Roizen discusses the latest health headlines YOU need to know.In this episode, Dr. Roizen talks about the latest health headlines that YOU need to know, including the following topics:  Exercise can be a boon to people with Parkinson's disease. Studies show a drastic reduction of symptoms. Smartphone app allows individuals to rate happiness at random times during the day. Those engaged in physical activity rated themselves much happier than those who were sedentary. In parts of the U.S. where poverty, obesity and smoking habits abound, cancer rates have increased nearly 50 percent since 1980. In other areas around the nation, there has been a 30 percent decline. Vaccine exemptions are on the rise in a number of states.  PLUS more... Bonus! This Bad Sleep Habit Leads to Overeating