Editor's note

Dear Readers,

For the last several years we've been devoting the May issue of the Health Letter to answering reader questions. The response has been overwhelmingly positive, so we're doing the same with this issue.

We want every article in the Health Letter to answer questions that are on readers' minds. But the question-and-answer format does so in a clear, direct way. And it taps directly into the expertise and experience of the members of our editorial board — and the Harvard faculty.