Meditation or exercise for preventing acute respiratory infection: a randomized controlled trial.
This study was designed to evaluate potential preventive effects of meditation or exercise on incidence, duration, and severity of acute respiratory infection (ARI) illness. Community-recruited adults aged 50 years and older were randomized to 1 of 3 study groups: 8-week training in mindfulness meditation, matched 8-week training in moderate-intensity sustained exercise, or observational control. The primary outcome was area-under-the-curve global illness severity during a single cold and influenza season, using the Wisconsin Upper Respiratory Symptom Survey (WURSS-24) to assess severity. Health care visits and days of missed work were counted. Nasal wash collected during ARI illness was assayed for neutrophils, interleukin-8, and viral nucleic acid. Of 154 adults randomized into the study, 149 completed the trial (82% female, 94% white, mean age 59.3 ± 6.6 years). There were 27 ARI episodes and 257 days of ARI illness in the meditation group (n = 51), 26 episodes and 241 illness days in the exercise group (n = 47), and 40 episodes and 453 days in the control group (n = 51). Mean global severity was 144 for meditation, 248 for exercise, and 358 for control. Compared with control, global severity was significantly lower for meditation (P = .004). Both global severity and total days of illness (duration) trended toward being lower for the exercise group (P=.16 and P=.032, respectively), as did illness duration for the meditation group (P=.034). Adjusting for covariates using zero-inflated multivariate regression models gave similar results. There were 67 ARI-related days of-work missed in the control group, 32 in the exercise group (P = .041), and 16 in the meditation group (P <.001). Health care visits did not differ significantly. Viruses were identified in 54% of samples from meditation, 42% from exercise, and 54% from control groups. Neutrophil count and interleukin-8 levels were similar among intervention groups. Training in meditation or exercise may be effective in reducing ARI illness burden.