As I have stated repeatedly, I am constantly on the look-out for positive news about alternative medicine. Usually, I find plenty – but when I scrutinise it, it tends to crumble in the type of misleading report that I often write about on this blog. Truly good research in alternative medicine is hard to find, and results that are based on rigorous science and show a positive finding are a bit like gold-dust.
But hold on, today I have something!
This systematic review was aimed at determining whether physical exercise is effective in improving cognitive function in the over 50s. The authors evaluated all randomised controlled trials of physical exercise interventions in community-dwelling adults older than 50 years with an outcome measure of cognitive function.
39 studies were included in the systematic review. Analysis of 333 dependent effect sizes from 36 studies showed that physical exercise improved cognitive function. Interventions of aerobic exercise, resistance training, multicomponent training and tai chi, all had significant point estimates. When exercise prescription was examined, a duration of 45–60 min per session and at least moderate intensity, were associated with benefits to cognition. The results of the meta-analysis were consistent and independent of the cognitive domain tested or the cognitive status of the participants.
The authors concluded that physical exercise improved cognitive function in the over 50s, regardless of the cognitive status of participants. To improve cognitive function, this meta-analysis provides clinicians with evidence to recommend that patients obtain both aerobic and resistance exercise of at least moderate intensity on as many days of the week as feasible, in line with current exercise guidelines.
But this is not alternative medicine, I hear you say.
You are right, mostly, it isn’t. There were a few RCTs of tai chi and yoga, but the majority was of conventional exercise. Moreover, most of these ‘alternative’ RCTs were less convincing than the conventional RCTs; here is one of the former category:
Community-dwelling older adults (N = 118; mean age = 62.0) were randomized to one of two groups: a Hatha yoga intervention or a stretching-strengthening control. Both groups participated in hour-long exercise classes 3×/week over the 8-week study period. All participants completed established tests of executive function including the task switching paradigm, n-back and running memory span at baseline and follow-up. Analysis of covariances showed significantly shorter reaction times on the mixed and repeat task switching trials (partial η(2) = .04, p < .05) for the Hatha yoga group. Higher accuracy was recorded on the single trials (partial η(2) = .05, p < .05), the 2-back condition of the n-back (partial η(2) = .08, p < .001), and partial recall scores (partial η(2) = .06, p < .01) of running span task.
I just wanted to be generous and felt the need to report a positive result. I guess, this just shows how devoid of rigorous research generating a positive finding alternative medicine really is.
Of course, there are many readers of this blog who are convinced that their pet therapy is supported by excellent evidence. For them, I have this challenge: if you think you have good evidence for an alternative therapy, show it to me (send it to me via the ‘contact’ option of this blog or post the link as a comment below). Please note that any evidence I would consider analysing in some detail (writing a full blog post about it) would need to be recent, peer-reviewed and rigorous.