Review of Bacopa-containing Polyherbal Products in Children Supports Use to Improve Cognition and Behavior
Ayurveda is a traditional system of medicine from India. Bacopa (Bacopa monnieri, Plantaginaceae) leaf is used in Ayurveda as a cognitive enhancer. Research in child and adolescent populations has found it to improve language comprehension, memory, focus, and attention. While research supporting the benefits of bacopa is extensive, there is less understanding of its effects in multi-herb combination formulas that are common in Ayurveda. The goal of this review was to systematically analyze clinical trials of multi-herb formulas containing high levels of bacopa and assess their effects on cognition, memory, and behavior in children and adolescents.
Online databases PubMed, Scopus, Cochrane Library, DHARA, Google Scholar, and CINAHL were searched for clinical trials in English published prior to April 2017 that reported on cognitive and behavioral effects of multi-herb formulas containing bacopa in children and adolescents. Websites for products meeting the inclusion criteria also were investigated, apparently to find leads to additional studies. Inclusion criteria included randomized, double-blind controlled trial design, use of a bacopa-dominant combination extract, and subjects between the ages of four and 18; participants were not taking any other interventions and trials had a sample size of ≥ 20 (10 if a crossover study) and duration of ≥ one month. A daily dosage of bacopa was calculated for each study.
For all studies with significant results and appropriate data, Cohen’s d effect size was calculated (small clinical effect = 0.2, medium clinical effect = 0.5, and large clinical effect = 0.8). The primary purpose was to summarize the evidence for bacopa-dominant formulas for cognitive and behavioral effects; secondary outcomes were safety and tolerability. Behavioral outcomes analyzed were grouped based on the ADHD (attention deficit hyperactivity disorder) framework and included such symptoms as hyperactivity, fidgeting, inattention, impulsivity, and difficulty organizing work and problems with peer relations. Cognitive testing was “assessed in terms of its true cognitive ability” and included tests of reasoning, comprehension, perception, language and numerical skills, and/or memory; corresponding symptoms measured included perceived difficulties with a cognitive domain or specific skills. Quality of methods was evaluated for each study using a modified Jadad Scale.
Nine studies were identified that met the inclusion criteria, five of which had sufficient data for effect size analysis. Six studies were reviewed for behavioral outcomes and cognitive abilities and found consistent positive effects, with impulsivity, attention, and visual perception having the largest improvements. Most subtests for specific cognitive domains were used in very few studies, as different studies measured different aspects of cognitive performance. Where effects were significant and effect sizes could be calculated, almost all were over 0.8 and most were well over 1.0, suggesting a substantial clinical effect. All included studies reported significant cognitive and/or behavioral improvements in at least some measures with the bacopa herbal formulas. The average quality rating for all included studies was 6.78, with the lowest being 5 and the highest, 10.
The additional herbs most commonly found in the multi-herb formulas were Gotu kola (Centella Asiatica, Apiaceae) leaf (n=9), ashwagandha (Withania somnifera, Solanaceae) root (n=3), shankhpushpi (Convolvulus prostratus, Convolvulaceae) leaf (n=2), spikenard (jatamansi; Nardostachys jatamansi, Caprifoliaceae) root (n=2), and false black pepper (Embelia Ribes, Primulaceae) seeds (n=2). The authors cite published evidence for cognitive benefits for several of the included herbs. The authors state that greater attention is required regarding safety, with 44% of included studies not reporting any safety outcomes; however, of the remainder, four reported no side effects and the last reported few.
The authors conclude that multi-herb formulas with bacopa appear to improve behavioral and cognitive outcomes in children and adolescents, particularly those with developmental disorders. They admit that focusing only on studies published in English, given bacopa’s rich history of use in Ayurveda, weakens the review. Additionally, with multiple herbs, it is difficult to understand the synergistic effects and interactions the herbs have on each other. And yet, “[t]he large number of easily accessible combination formulas highlights the importance of understanding the research behind them, as well as their safe use in child and adolescent populations.” No conflict of interest was reported.
Kean JD, Downey LA, Stough C. Systematic overview of Bacopa monnieri (L.) Wettst. dominant poly-herbal formulas in children and adolescents. Medicines (Basel). November 22, 2017;4(4):86. doi: 10.3390/medicines4040086.