The single-arm trial provides “encouraging findings” for the specific R. rosea extract called Rosalin, WS 1,375 (Dr. Willmar Schwabe GmbH) to enhance a range of brain functions in healthy adults, including alertness, orientation, and executive attention.
“With regard to the ANT [attention network task], we found a marked reduction in overall reaction time from baseline to week 12 accompanied by a significant reduction in the executive effect, that is, the difference in reaction time to congruent and incongruent stimuli, a significant modulation of the orienting effect and a reduction in error rate,” wrote scientists from the University of Lübeck and Dr. Willmar Schwabe GmbH in Phytotherapy Research.
“A decrease in reaction time was also seen in the Go/Nogo task as well as the divided attention task with a reduction in error rate clearly apparent in the latter task as well. Taken together, these findings suggest a beneficial effect of R. rosea on complex attention functions.”
Growing interest
The potential cognitive benefits of R. rosea have been reported many times before. The primary health use of the herb has been for stress, mental and physical fatigue, depression, and to boost energy. German scientists recently reported that the R. rosea extracts may also improve the symptoms of ‘burnout’, with considerable effects already being detectable after the first week (Neuropsychiatric Disease and Treatment, Vol. 13, pp. 889–898).
Rhodiola is in the number 37 best-selling herbal dietary supplement in the mass channels in 2019, with sales of $8,737,768 (a decline of 9.7% from 2018), according to a report in Herbalgram 127. For an extensive review of R. rosea in HerbalGram 56, please click HERE.
Study details
The researchers recruited 50 healthy adults with an average age of 41.2 to participate in their study. The single arm study design meant that all of the participants received the same active supplement (400 mg per day of Rosalin, WS 1,375), for 12 weeks (there was no placebo group). WS 1,375 is standardized to 3–8% rosavins, said the researchers.
All participants underwent a battery of neuropsychological tests and an event‐related brain potential measurement in a dual task paradigm. These tests were performed at the start of the study, at the mid-way point (6 weeks), and then at the end (12 weeks).
The results indicated that reaction times improved for the attention network task (ANT), the Go/Nogo task, and the divided attention task.
“Moreover, the orienting effect and the executive effect in the ANT showed an improvement,” said the researchers.
“These encouraging findings need to be substantiated by a double‐blind placebo‐controlled study,” they added.
“Moreover, we propose that the dual task methodology is excellently suited to assess mental fatigue and thus any possible beneficiary effects of R. rosea on mental resources.”
Source: Phytotherapy Research
Published online ahead of print, doi: 10.1002/ptr.6778
“Effects of a Rhodiola rosea extract on mental resource allocation and attention: An event‐related potential dual task study”
Authors: T. Koop et al.