Bacopa extract verbetert mogelijk het geheugen bij ouderen
Reviewed: Morgan A, Stevens J. Does Bacopa monnieri improve memory performance in older persons? Results of a randomized, placebo-controlled, double-blind trial. J Altern Complement Med. 2010;16(7):1-7.
Bacopa (Bacopa monnieri, Scrophulariaceae) is an aquatic plant that has been used in Ayurvedic medicine to enhance memory, intellectual function, and longevity. Several randomized, blind, controlled clinical trials demonstrate the benefits of bacopa extract on memory and learning, including one that also improved depression and anxiety measures in the elderly without dementia.1 A Phase I clinical trial demonstrated the safety and tolerability of BacoMind™ (Natural Remedies Pvt. Ltd., Bangalore, India), a standardized extract of bacopa, in healthy volunteers.2 The purpose of this randomized, placebocontrolled, double-blind study was to evaluate the efficacy and safety of BacoMind in older people (the population that experiences memory impairment).Researchers recruited participants from the general population of Northern Rivers region, New South Wales, Australia via media announcements and staff at Southern Cross University, Lismore, New South Wales, Australia. Volunteers 55 years or older who were without dementia or depression as assessed with validated scales were included. Participants had to be healthy and not using psychoactive medications, herbal medications, recreational drugs, or consuming more than 4 alcoholic drinks per day.Participants (n = 98; average age 65 years; range 55-86 years) were randomized to receive one 300 mg tablet/day BacoMind or placebo for 12 weeks. BacoMind is an alcoholic extract (herbto-extract ratio, 20:1) standardized to contain total bacoside saponin content of 40%-50%. BacoMind is standardized to 9 active constituents: bacoside A3, bacopaside I, bacopaside II, jujubogenin, bacopasaponin C, bacosine, luteolin, apigenin, and b-sitosterol-D-glucoside. The dosage evaluated was based on the manufacturer’s recommendation and was taken after a meal. Compliance was assessed by counting tablets at the end of the study.
Efficacy was evaluated with 3 validated neuropsychologic tests and a memory complaint questionnaire. The Rey Auditory Verbal Learning Test is a word-list learning test to assess aspects of memory including immediate recall, delayed recall, and retroactive and proactive interference. Rey-Osterrieth Complex Figure Test assesses visuospatial ability and visual memory. Trail Making Test measures scanning and visuomotor tracking, and involves cognitive processing (including memory) along with psychomotor speed. The Memory Complaint Questionnaire quantifies subjective memory complaints of aging.
At baseline, there were significant differences between treatment groups in the mean scores on the Rey-Osterrieth delayed recall tasks at both 3 minutes (Bacopa 18.2 ± 6.4; placebo 14.6 ± 5.9; P=0.005) and 30 minutes (Bacopa 18.3 ± 5.9; placebo 14.9 ± 6.4; P=0.008, respectively). There were no other baseline differences between groups. There were 17 withdrawals, including 9 in the bacopa group and 2 in the placebo group due to adverse effects, mostly gastrointestinal complaints (stool frequency, nausea, and abdominal cramps).
The Rey Auditory Verbal Learning Test consists of 15 tasks. Of these 15 tasks, BacoMind significantly improved memory function on 6 of the tasks compared with placebo: trial a4 (P=0.000) (the level in the paper; presumably this is a typographical error), trial a5 (P=0.016), trial a6 (postdistraction trial; P=0.000) (ditto), trial a7 (delayed-recall trial; P=0.001) (total learning summary trials a1–a5; P=0.011) and retroactive interference index (P=0.048). (Ed. Note: P values are somewhat suspect in this trial.) For all of the other efficacy tests there were no significant differences from placebo.
The authors conclude that bacopa significantly improves memory acquisition and retention in older Australians as measured by the Rey Auditory Verbal Learning Test. They state that the study demonstrated an improvement in the learning rate and had no effect on the forgetting rate. They caution against concurrent use of bacopa and acetylcholinesterase inhibitor medications, which are commonly prescribed for dementia. This study reported a higher incidence of GI side effects than was reported in the Phase I trial of BacoMind. This difference may be due to the older age of the population included in the current study, which may have a lower tolerability to bacopa, possibly due to its high saponin content.
This study was well designed and executed; however, an improvement on one test does not show decisively that bacopa improves memory acquisition and retention. This study bears repeating since there was a significant difference at baseline (a study limitation). It might also be constructive to evaluate a population with memory loss.
Oliff HS. Concentrated bacopa extract improves outcomes on cognitive and affective tests in elderly.HerbClip. February 13, 2009. (No. 090586-370) Austin, TX: American Botanical Council. Review of Effects of standardized Bacopa monnieri extract on cognitive performance, anxiety, and depression in the elderly: a randomized, doubleblind, placebo-controlled trial by Calabrese C, Gregory WL, Leo M, et al. J Altern Complement Med. 2008;14(6):707-713.
Oliff HS. Special extract of bacopa examined for safety. HerbClip. July 13, 2007. (No 060571-332) Austin, TX: American Botanical Council. Review of Safety evaluation of BacoMindTM in healthy volunteers: A phase I study by Pravina K, Ravindra KR, Goudar KS, et al. Phytomedicine. 2007;14:301-308.