What foods should i avoid during the time that i will be breastfeeding? i've been told that alcohol, jalapenos, and onion are a danger to the baby?

Not dangerous!: "classic allergenic foods:" cow's milk; eggs; peanuts; tree nuts; wheat; soy; fish. Some breast-feeding women say that avoiding these items or other spicy/gassy foods, such as onions/cabbage, can help — but this hasn't been proved through research. If your baby becomes fussy or develops a rash, diarrhea or congestion soon after nursing, these signs could indicate a food allergy & need to avoid.