I can tell you from experience that if you are told that something you are doing or not doing is causing pain, you will be highly motivated to correct that issue. For me, it hasn't yet been food, but it was (and still is) something that I have great difficulties with.
There is a saying that goes like this: "A person won't make any changes until the pain of change is less than the pain of staying the same." That's true of all actions, including food choices, and it is very accurate. If you have any form of arthritis, including (if not especially) gout, you may see yourself in that saying.
Red food dye is a prime example. While it may not affect those suffering from osteoarthritis, if you have gout or rheumatoid arthritis, it could be a problem. The reason it is such a problem is that it is not made from a plant, it is made from a bug. After learning that, I became a whole lot less enamored of all things red.
While many of us know that sulfites are bad for asthmatics, you may not be aware that it can make arthritis worse. This chemical is found naturally in many foods. Wine is a good example, but it can also be found in grapes. When added to foods as a preservative, it is in much larger amounts and can cause significant problems. I urge you to check the ingredients list of all foods to make sure this is not in it.
Processed foods are another area that can cause some serious pain, and arthritis is one of the conditions that can be made worse. Part of it has to do with the weight gain that can come from a diet largely consisting of these products. However, the glycemic index and other factors can cause both OA and RA to act up.
What's worse is processed meats and the pain it can cause gout sufferers. Most processed meats are both colored by food dye and filled with organ meat. The organs of all animals are extremely high in purine, a constituent of protein. The purine is broken down in the body and the waste product is uric acid. If the kidneys are unable to filter that out, a gout flare up is probable.
If you have any form of arthritis, ask your doctor to refer you to a nutritionist. The nutritionist can help you design a diet that will avoid foods that could cause you pain. He or she will also help you make sure that diet is well balanced, which is a key to good health throughout your whole body.