Comment by sleighboy

From the summary: "The authors were surprised by the small amount of work identified. In particular, there were very few studies that followed the same individuals longitudinally, there was lack of analysis of confounding variables and there was failure to undertake appropriate statistical analysis."

The whole report has a tone of being the best they could conclude with poor data which is stressed repeatedly. Those numbers put in context of the opinions of the source data makes them not so impressive.