I've been looking for a list of all foods and supplements that support the Th1 side of the immune system. At the same time, I also wanted to know which foods and supplements to avoid because they stimulate the Th2 side. I finally found this article, which provides a fairly exhaustive list of both. Granted, I've never heard of the doctor who wrote it (even though his practice is a short 20 minute drive from me), but his article seems thoroughly supported by citations to reputable publications.
[5/29/12 update: This article from DiagnoseMe.com also contains a similar list near the bottom of the page. There are some interesting additions, like noni juice, thyroid medications, and something called "Neem."]