Researchers conducting a systematic review that examined the results of 24 individual studies with over 2,500 participants have reported new findings about the potential role of herbal supplements for individuals who suffer from mood-related issues.
"Our review and summary of the literature on herbal remedies and dietary supplements for anxiety should aid mental health practitioners in advising their patients and provide insight for future research in this field." said Shaheen Lakhan, co-author of the study from the Global Neuroscience Initiative. "We found mixed results — while passionflower or kava and L-lysine and L-arginine appeared to be effective, St John's Wort and magnesium supplements were not."
The review conlcuded that nutritional and herbal supplementation may be an effective tool for anxiety and anxiety-related conditions. There were no serious side effects noted resulting from supplementation in these cases, but it is also noted that any positive effects seen in the studies could be a result of a placebo effect, which may have significant short-term psychological impact on participants.
21 of the studies reviewed were randomized control trials. Of these, 71% (15 trials) showed positive results. The small number of studies for each individual supplement prevents this review from being a true meta-analysis; however, based on the available data, researchers believe there is evidence suggesting that extracts of passionflower or kava and combinations of L-lysine and L-arginine may be helpful.
"For all three of the herbal supplements we reviewed, more research needs to be done to establish the most effective dosage and to determine whether this varies between different types of anxiety or anxiety-related disorders. Herbal medicines hold an important place in the history of medicine as most of our current remedies, and the majority of those likely to be discovered in the future, will contain phytochemicals derived from plants," said Lakhan.
The Global Neuroscience Initiative's findings were published in the open access Nutrition Journal.
DSIB: Passion Flower
Nutrition Journal: Nutritional and herbal supplements for anxiety and anxiety-related disorders