A new study led by researchers at the University of Cincinnati (UC) School of Medicine suggests that the practice of tefillin (phylacteries), which involves fitting an arm with leather bands as part of daily prayer, would enjoy cardiovascular health benefits.

Jack Rubinstein, MD, an associate professor in the Division of Cardiovascular Health and Diseases and a UC Health cardiologist, says he recruited 20 Jewish men living in Cincinnati, nine who use tefillin daily and 11 non-tefillin users, into the study. His team of researchers recorded baseline information on all participants during the early morning hours and then additional data after using tefillin for 30 minutes. The male participants ranged in age from 18 to 40 and were all in good health.

They monitored the participants’ vital signs, extracted blood for analysis of circulating cytokines and monocyte function while measuring blood flow in the arm that was not wrapped with tefillin.

Tefillin are used in morning prayers by Jewish men over the age of 13, placed on the non-dominant arm around the bicept and forearm in a tight manner but not tight enough to impair blood circulation for about 30 continuous minutes. Prayers are performed by standing and sitting repeatedly so that the strap must be re-adjusted.

Blood flow was greater in men who used tefillin daily and improved in all participants after using it only once as part of the study, Rubinstein explained. Men who used tefillin daily also had fewer circulating cytokines (signaling molecules that can cause inflammation and negatively impact the heart) compared to non-users, suggesting that almost daily use causes an effect similar to that seen with other methods of provoking remote ischemic preconditioning, as an effect. 

According to the professor, the use of tefillin may offer protection against acute ischemic reperfusion injury resulting from a heart attack.