Looking for mechanisms to explain stress reduction with yoga

Studies commonly report less stress among people who practice yoga. Examples are here in pregnancy, here among musicians, and here in healthy women and cancer survivors.

This study, by Ohio State University researchers searched for the mechanism underlying the benefit.

First, the details.

  • 50 healthy women, including 25 novices and 25 experts, were exposed to each of thetreatment groups.
    • Yoga
    • Movement control
    • Passive-video control
  • Participants then performed tasks to increase their stress including immersing their foot into extremely cold water, after which they were asked to solve successively more difficult math problems without paper or pencil.

And, the results.

  • Yoga boostedparticipants’ positive affect compared to the other groups.
  • But no overall differences in inflammatory or endocrine responses were observed.

However, novices’ blood levels of interleukin (IL)-6 were 41% higher than in experts during the yoga sessions, with the odds of a novice having detectable C-reactive protein (CRP) 4.75 times as high as an expert.

This difference in stress responses between experts and novices provides a plausible mechanism for their divergent serum IL-6 data.

  • Experts produced less lipopolysaccharide-stimulated IL-6 in response to the stressor than novices, and IL-6 promotes CRP production.

The bottom line?

IL-6 is a small protein (cytokine) released from tissues in response to stress. CRP is a byproduct of inflammation — a form of stress.

The authors concluded, “If yoga dampens or limitsstress-related changes, then regular practice could have substantialhealth benefits.”

The level of stress at the start of the treatment session seemed to influence the response to stress reduction.

1/20/10 19:16 JR

Hi, I’m JR

John Russo, Jr., PharmD, is president of The MedCom Resource, Inc. Previously, he was senior vice president of medical communications at, a complementary and alternative medicine website.