Didn't I read just the opposite in an article on Hacker News just a few hours ago? It claimed that researchers were mistaken in the past, yet the studies cited here are from the past 10 years.
http://www.slate.com/articles/health_and_science/science/201...
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1071721/
More balanced:
http://journals.plos.org/plosone/article?id=10.1371/journal....