Both - apply topically and swap your cooking oils for it too. Some online stores sell coconut oil products - not fake, scented stuff, but made from real coconut oil.

There is loads of info and research at www.coconutresearchcenter.org

I'd also look into juicing which is brilliant. There is an author, Cherie Cabom I think, who is nicknamed 'The Juice Lady.'

Because flare ups tend to happen in times of stress, illness etc, addressing those issues are of course important but I think all link back to immune system deficiencies (stress wears it down as well as a poor diet). Some good probiotics will help strengthen that too.

Good luck, hope thar helps