My doctor told me this:
1) lower your stress
2) 10 minutes of exercise (like brisk walking) a day
3) the ole' one glass of red wine a day
went through the roof in the course of a year, and I had switched from a very stressful job to one that was far better, I took a train and walked 10 minutes to work downtown, and drank a glass of wine every other day or so.