I think this is the article Laupala is referring to.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3984490/
If you read the whole article, including the part about placebo effect and attempts at double blind study, the result is not as rosy as first presented.
The study with the rosy results is abstracted here.
http://www.ncbi.nlm.nih.gov/pubmed/24260334