| Popis: |
Background: Subjective cognitive impairment (SCI), is conceptualised as the preclinical phase of dementia, and is characterised by a worsening of cognitive functioning, particularly within the area of memory. Due to the increased risk of developing future objective decline, and the lack of pharmacological interventions available to treat SCI, complementary medicines (CMs) are becoming more widely used by older adults, particularly herbal and nutritional medicines. The aim of this systematic review was to describe the study characteristics, methodologies, and intervention efficacy of studies on herbal and nutritional medicines for older adults with and without SCI. Method: Four databases (Cochrane, MEDLINE, CINAHL, and PsycInfo) were searched from database inception until 20 February 2022. Articles were included in the review if they met the following criteria: study population of older adults with and without SCI, herbal and nutritional medicines as an intervention, evaluated cognitive outcomes, and were randomised control trials. Results: Data was extracted from 20/6,006 eligible full-text articles, and risk of methodological bias in accordance with the Cochrane review process for randomised trials, (ROB 2) was assessed. Nine studies used an SCI population, with the remaining eleven, older adults without SCI. Most studies employed parallel, randomised, placebo-controlled designs, and were 12 weeks in length. Sixteen out of twenty studies used a herbal supplement, with most of these using a form of Ginkgo biloba or Bacopa monnieri. Measures of cognition varied across the studies, with 13/20 studies reporting improvements in at least one area of cognitive functioning across time, in the intervention group (compared to placebo). A total of 14/20 studies were deemed as having an overall high methodological risk of bias, 5/20 had some concerns, and only one study (using an SCI population) was assessed as having a low risk of methodological bias. Conclusions: This was the first review to conduct an extensive search of randomised control trials using herbal and nutritional medicines, to improve cognitive functioning in older adults with, and without SCI. Further work needs to be done in classifying and understanding SCI, before future studies can more accurately determine the efficacy of these interventions. |
