Go to Church and live longer?

Research published last month found that regular churchgoers were 33 per less likely to die during the 16 year study period than those who never attended. Frequent attenders also showed significantly lower risk of cancer (21% improvement) and cardiovascular disease (27% improvement). Even those who only go sporadically had improved survival rates compared to those who never do. Even when issues like smoking were factored out the improvements remained the same across the board. More details on for example www.cnn.com/2016/05/16/health/religion-lifespan-health

The study followed the lives of 74,534 American nurses, all women. So what of men? Well there are other studies out there which show that the effect is less marked, but still significant for men. But all these studies seem to be American. I googled churchgoers live longer research and couldn't find a single British study on the net. I wonder why our epidemiologists don't think it's worth investigating…

What about reasons why this should be so? Here's some possibilities:
o being part of a supportive community?
o taking part in communal singing (which has independently been shown to reduce stress and boost health)?
o clean living – less drugs, tobacco and alcohol?
o believing that your life has value and purpose?
o finding peace of mind?
o trusting that you  are loved – by God and others?

What do you think?