Six years ago， the Harvard Medical School made a commitment to<br >support a publication designed to provide the public with accurate<br >and timely health information. The result was the Harvard Medical<br >School Health Letter， which reaches over 300，000 subscribers each<br >month.<br > It is with great pride that we now present The Harvard Medical<br >School Health Letter Book a completely up-dated synthesis of in-<br >formation that has appeared in the Health Letter. Together， the<br >Harvard Medical School Health Letter and the Health Letter Book<br >are the Harvard Medical School s principal effort to inform the gen-<br >eral reader about human health and disease. On behalf of the Fac-<br >ulty of Medicine， I want to congratulate Drs. Timothy Johnson and<br >Stephen Goldfinger and their colleagues for these superb contribu-<br >tions to learning in medicine. I hope that they will help you， the<br >reader， to care more effectively for your own health.<br > Daniel C. Tosteson<br > Dean<br > Harvard Medical School<br >