Foods that increase inflammation are refined carbs, bad fats (hydrogenated), phony fats, and of course anything that you're allergic to or intolerant of.
Many people are intolerant of Night Shade Veggies, and these can cause inflammation. Potatoes (especially if they have a green skin), eggplant, tomatoes (especially if cooked and concentrated into a sauce), tend to be the worst offenders of the nightshade family.
Dehydration will increase inflammation.
foods that decrease inflammation with natural anti-inflammatory properties are fish oils, cold, deep-water, and/or fatty fish like mackeral, swordfish and salmon. Anything high in Omega 3 and 5's like Flax seed oil, Udo's Choice, most nuts and seeds.
Bromelain, found in pineapple, reduces inflammation.
Barley, especially barley tea
apples - especially the skin of green apples
anti-oxidants (Skin Food plus ALA)