Alexa Fleckenstein, MD, is board certified in internal medicine and also holds a degree in natural medicine. She practiced integrative medicine in the Boston area for more than 30 years, using both conventional and natural treatments. Dr. Fleckenstein has been a featured health expert on radio and TV shows and has contributed to magazines such as "Body""and Soul "and "Bottomline Health." She is the author of "Healthy to 100 "and "Health20. "She lives in Brookline, MA.