Women who attend church more than once a week live longer than those who do not, according to a new study by researchers at Harvard University's public health graduate school.

The University's researchers wrote: "Religion and spirituality may be an underappreciated resource that physicians could explore with their patients, as appropriate."

The study analysed data on more than 74,000 women over 16 years, and found that those who attended church more than once a week were 33 per cent less likely to die in that time than those who never went to church.

"Compared with women who never attended religious services, women who attended services more than once per week had a 33 per cent lower mortality risk," the researchers wrote in a paper in the JAMA Internal Medicine journal.

"In examining the potential pathways from religious service to all-cause mortality, we found that depressive symptoms, smoking, social support, and optimism were potentially important mediators," they added.

The new study was taken from information gathered for the Nurses' Health Study, which asked American women, all of whom were nurses, to fill in questionnaires about their life from 1996 to 2012.

Almost a fifth of those surveyed reported attending church more than once a week. Forty per cent went once a week, one in six went less frequently and just a quarter never attneded.

Between 1996 and 2012, 13,537 of the 74,534 women surveyed died. One third died from cancer, and a fifth from cardiovascular disease.

The study found that those in the first group were one third less likely to have died than those who never attended church, 27 per cent less likely to have died from cardiovascular disease and 21 per cent less from cancer.

Less frequent church-goers also reported health benefits.

Weekly churchgoers were 26 per cent less likely to die than those who never went, and those who occasionally went had a 13 per cent lower chance.

The data ties church attendance with longer lifespans for women, however the study "does not address philosophical or theological questions such as 'Does God (or any higher being) exist?", Dr Dan German Blazer pointed out, writing in a commentary article on the data.

"The data do not validate claims made about some of the positive benefits of specific religious experiences, claims made even by medical professionals.

"Reasons for attendance at religious services may vary appreciably across individuals, such as religious devotion, lifelong habits, social pressures, and perhaps simple loneliness causing individuals to search for a support group with which to connect.

"We have no assurance that attendance at religious services is a marker of the strength of one's religion or spirituality and no description of the extent of private practices of spirituality, such as prayer, or perceptions of spiritual well-being among the participants."