A 2012 study by the University of Wisconsin attempted to resolve whether mindful meditation was more effective than exercising and non exercising control groups.

For this, adults 50 years and older were assigned to 1 of 3 groups and given either an 8-week course in mindfulness meditation by Jon Kabat, 8-weeks of exercise, or observational control.

The result: From the 154 randomized adults there were 67 illness related events in the control group, 32 in the exercise group and 16 in the meditation group.

It seems like meditation may indeed help improve immune health!