New study reveals parenthood is associated with lower blood pressure

They turn Dad's hair gray, but children can now take partial credit for the health of Mom's heart.

A new Brigham Young University study found that parenthood is associated with lower blood pressure, particularly so among women.

Julianne Holt-Lunstad, a BYU psychologist who studies relationships and health, will publish her report in the peer-reviewfwoed journal Annals of Behavioral Medicine.

Of course parenthood is not the only route to low blood pressure - daily exercise and a low-sodium diet also do the trick. The noteworthy aspect of the study is the idea that social factors may also protect physical health.

"While caring for children may include daily hassles, deriving a sense of meaning and purpose from life's stress has been shown to be associated with better health outcomes," Holt-Lunstad said.

The study involved 198 adults who wore portable blood pressure monitors, mostly concealed by their clothes, for 24 hours.

The monitors took measurements at random intervals throughout the day - even while participants slept. This method provides a better sense of a person's true day-to-day blood pressure. Readings taken in a lab can be inflated by people who get the jitters in clinical settings. It's a real phenomenon known as the "white coat" effect, and it can mess up the results of studies done without the portable monitors.

A statistical analysis allowed the researchers to account for other factors known to influence blood pressure - things like age, body mass, gender, exercise, employment and smoking - and zero in on the effect of parenthood. For parents overall, the 24-hour blood pressure readings averaged 116 / 71.

All other things being equal, parents scored 4.5 points lower than non-parents in systolic blood pressure (the top number) and 3 points lower than non-parents in diastolic blood pressure. Holt-Lunstad says the size of the difference is statistically significant, but she warns against hastily making major life changes based on this finding alone.

"This doesn't mean the more kids you have, the better your blood pressure," Holt-Lunstad said. "The findings are simply tied to parenthood, no matter the number of children or employment status."

The effect was more pronounced among women, with motherhood corresponding to a 12-point difference in systolic blood pressure and a 7-point difference in diastolic blood pressure.

And if fulfilling relationships make your body feel better, it's no surprise what stressful relationships can do. See this story on "frenemies" for more about that.