Objectives: This study gathers preliminary data about the biologic effects of repeated Swedish massage therapy compared to a light-touch control condition.
Design: The study design was a 5-week comparison of repeated Swedish massage and light touch on oxytocin (OT), arginine-vasopressin (AVP), adrenal corticotropin hormone (ACTH), cortisol (CORT), circulating phenotypic lymphocyte markers, and mitogen-stimulated cytokine function.
Setting: The setting was an outpatient research unit in an academic medical center.
Participants: The study subjects were medically and psychiatrically healthy young adults.
Intervention: The study comprised 45 minutes of Swedish massage or light touch, using highly specified and identical protocols, either weekly or twice weekly for 5 weeks.
Outcome measures: The outcome measures were mean differences between massage and light touch on OT, AVP, ACTH, CORT, lymphocyte markers, and cytokine levels.
Results: Compared to the touch control condition, weekly Swedish massage stimulated a sustained pattern of increased circulating phenotypic lymphocyte markers and decreased mitogen-stimulated cytokine production, similar to what was previously reported for a single massage session, while having minimal effect on hypothalamic-pituitary-adrenal function. Twice-weekly massage produced a different response pattern with increased OT levels, decreased AVP, and decreased CORT but little effect on circulating lymphocyte phenotypic markers and a slight increase in mitogen-stimulated interferon-γ, tumor necrosis factor-α, interleukin (IL)-1b and IL-2 levels, suggesting increased production of pro-inflammatory cytokines.
Conclusions: There are sustained cumulative biologic actions for the massage and touch interventions that persist for several days or a week, and these differ profoundly depending on the dosage (frequency) of sessions. Confirmatory studies in larger samples are needed.