If I eat healthy foods and exercise, can I reverse damage from a poor diet?

32 year old male. This year I changed my diet to a Vegetarian/Mediterranean diet and I run 5 or 6 days per week for cardio and work out. I ate a very poor diet, fast food and such, for most of my life. Will changing my diet as I have reverse any damage I probably did to my body by eating poorly and not working out?

http://ping.fm/xaocc