"Religiosity appears to have little affect on preventing hypertension, or high blood pressure, and those study participants proclaiming to be the most religious were actually the most likely to have hypertension. The study was conducted by medical students at the Loyola University Chicago Stritch School of Medicine and presented on April 30 at the meeting of the Society of Teachers of Family Medicine in New Orleans.
Although a small study presented at a small meeting, it is yet one more report that chisels away at the notion that prayer and belief alone offer significant health benefits.
Many studies indeed have shown that those who attend weekly religious services or participate in church activities have at least marginally better health than non-participants. Yet these studies have focused primarily on physical participation: getting out of the house to a weekly service and being part of a community.
Marginally significant results aside, these earlier studies could not tease apart what it was about religion — the spiritual act of believing or the physical acts of participating and interacting with neighbors — that provided the purported benefit.
The Loyola study focused more on the spiritual, not whether a person merely attends church but whether they "carry [their] religion over into all other dealings in life," as cited in the study. Those who were most religious in this regard were the least healthy in terms of high blood pressure.
Other recent studies have focused on spirituality, too, to see if that alone could lower blood pressure, perhaps through mechanisms such as stress reduction. Yet prayer and spirituality were associated with higher blood pressure in a study of more than 3,000 adults published in January 2009 in Social Science Medicine; and they offered no benefit for preventing hypertension for approximately 1,600 women in a study published in June 2009 in Annals of Behavioral Medicine.
Even a life of the cloth seems to provide little protection. The obesity rate among United Methodist clergy is 40 percent, about 10 percent higher than the national rate, as reported in the September 2010 issue of Obesity.
Meanwhile, just about anything that gets someone out of the house can be helpful. Playing bingo, for example, even in a non-religious setting, is associated with a 40-percent reduction in death risk and 65-percent reduction in disability among the elderly, according to a study published in June 2009 in the Archives of Internal Medicine."
LiveScience, Christopher Wanjek, 05 May 2011
I quote this article at length, because it points to a very important effect of religion, the social aspect. So there aren't any metaphysical effects or effects from belief itself, only the effect that getting out of the house provides. Maybe atheists should gather once a week too.
On a personal note, not long ago I actually had fairly high blood pressure. I could hear the blood pumping when I was laying on my bed with the ear to the pillow. Then I started to excercise once a week, and that helped. Now I can't hear the blood pumping anymore. No need for spirituality, just common sense.