I have to wonder if the people being studied had some kind of defficiency that the daily pills were remediating. At a guess, it might be magnesium, which our foods (even 'organic' ones) have become relatively defficient in over the last century or so due to gradual soil depletion. (Farming is a soil-extractive process; farmers put back nitrogen and phosphorous as lack of those is reflected in crop yield - but they don't replace magnesium or some other minerals.) On the other hand, most of the daily multivitamins I've looked at provide magnesium *oxide*, which is very poorly absorbed - so I'm probably wrong here...