A Preliminary Study of the Effects of a Single Session of Swedish Massage on Hypothalamic–Pituitary–Adrenal and Immune Function in Normal Individuals

Abstract

Massage therapy is a multi-billion dollar industry in the United States with 8.7% of adults receiving at least one massage within the last year; yet, little is known about the physiologic effects of a single session of massage in healthy individuals. The purpose of this study was to determine effects of a single session of Swedish massage on neuroendocrine and immune function. It was hypothesized that Swedish Massage Therapy would increase oxytocin (OT) levels, which would lead to a decrease in hypothalamic-pituitary-adrenal (HPA) activity and enhanced immune function. The study design was a head-to-head, single-session comparison of Swedish Massage Therapy with a light touch control condition. Serial measurements were performed to determine OT, arginine-vasopressin (AVP), adrenal corticotropin hormone (ACTH), cortisol (CORT), circulating phenotypic lymphocytes markers, and mitogen-stimulated cytokine production. This research was conducted in an outpatient research unit in an academic medical center. Medically and psychiatrically healthy adults, 18-45 years old, participated in this study. The intervention tested was 45 minutes of Swedish Massage Therapy versus a light touch control condition, using highly specified and identical protocols. The standardized mean difference was calculated between Swedish Massage Therapy versus light touch on pre- to postintervention change in levels of OT, AVP, ACTH, CORT, lymphocyte markers, and cytokine levels. Compared to light touch, Swedish Massage Therapy caused a large effect size decrease in AVP, and a small effect size decrease in CORT, but these findings were not mediated by OT. Massage increased the number of circulating lymphocytes, CD 25+ lymphocytes, CD 56+ lymphocytes, CD4 + lymphocytes, and CD8+ lymphocytes (effect sizes from 0.14 to 0.43). Mitogen-stimulated levels of interleukin (IL)-1ß, IL-2, IL-4, IL-5, IL-6, IL-10, IL-13, and IFN-γ decreased for subjects receiving Swedish Massage Therapy versus light touch (effect sizes from -0.22 to -0.63). Swedish Massage Therapy decreased IL-4, IL-5, IL-10, and IL-13 levels relative to baseline measures. Preliminary data suggest that a single session of Swedish Massage Therapy produces measurable biologic effects. If replicated, these findings may have implications for managing inflammatory and autoimmune conditions.