From the ABC News Site

http://onhealth.com/ch1/briefs/abstract/item,37745.asp


M a r c h   1 8 ,   1 9 9 9

Hormone Lowers Moms' Blood Pressure

A new study shows increased levels of a hormone produced while nursing can
lower mothers' blood pressure. The findings, presented Wednesday at the American
Psychosomatic Society Annual Meeting in Vancouver, British Columbia, may
explain why many mothers claim to feel relaxed after nursing their babies.

Researchers at the University of North Carolina at Chapel Hill studied 26
mothers of infants, 14 of whom breast-fed and the remaining 12 bottle-fed
their babies. Blood pressure and blood levels of the hormone oxytocin were
measured before, during and after women were asked to discuss recent
stressful events in their lives.

Study results showed the breast-feeding mothers showed a blood pressure
response during the stressful event, but their blood pressure was lower than
the bottle-feeding moms before and after the event.

The researchers also found that when the study participants were monitored
24 hours a day at home, blood pressure levels of high oxytocin reactors were
10 points lower than the bottle-feeding moms one hour after nursing and six
to nine points lower during sleep.

"Oxytocin is most commonly known for its role in the letdown of milk during
breast-feeding, but also has effects on brain areas involved in emotion and
stress responses," says researcher Dr. Kathleen Light.