Not only that, but a lot of the suggestions seem to ignore the "good scientific backing" part of OP's question. For example, omega-3 has been mentioned several times, but if you look at any of the sources that more responsible commenters have linked to it's clearly on the "slight" to "none" side evidence-wise. I have no opinion on omega-3 personally. It's fine if people take it. It's just not an answer to the question that was posed.