What are some foods that can offer the same health benefits as tomatoes?

Recently, my mother discovered that she could cut down on her chronic pain by quite a lot by cutting out certain foods, including tomatoes and potatoes as these are members of the nightshade family and are not so good for people with nasty, all-encompassing arthritis like my poor momma. For some reason, I have been consuming an abundance of tomatoes, mostly in the form of tomato juice (it is so delicious) so I decided to look up the health benefits of tomatoes. I have discovered that tomatoes are really good for helping to prevent cancer, diabetes and heart troubles, plus they are excellent for bones, skin and the damage smoking does to the body, which are all things that would greatly benefit my mother. Here are two links which illustrate the health benefits of tomatoes.

So, my question is this: what are some foods that will not exacerbate her arthritis but will offer similar health benefits to tomatoes?