For our family, I extended breastfeeding till she was 3.5 years old. I truly believe this extension made it easier for her to outgrow many of her food allergies. I have also noticed that she rarely gets sick (her whole 6 years of life we have only had to go into the doctor's office for visits due to her extreme reflux and torticollis) or if she does get sick it doesn't last past 3 days. I also think the extension did in some way did provide comfort with her severe reflux.
I'm looking forward to hearing your results/story.