Traditional Chinese Medicine: An effective add-on therapy for treating Alzheimer’s disease? Original paper

In this meta-analysis, combining Acorus tatarinowii and Polygala tenuifolia (two herbs of traditional Chinese medicine) alongside conventional drugs improved cognition and functioning in Chinese older adults with Alzheimer's disease more effectively than conventional drugs alone.

The efficacy and safety of combining Acorus tatarinowii (AT) and Polygala tenuifolia (PT), 2 roots used in traditional Chinese medicine (TCM), with and without conventional drugs for the treatment of Alzheimer’s disease (AD).

Primary outcomes were the Mini-Mental State Examination (MMSE; a measure of cognitive function), activities of daily living, and Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-C; assessing the severity of cognitive symptoms of dementia).

1,103 Chinese older adults (average ages of 57–81; 53% women and 47% men) with AD.

A meta-analysis of 16 randomized controlled trials was performed. All the studies were conducted in China. The duration of the studies ranged from 12 weeks to 6 months.

The daily doses of the Chinese medicinal herbs ranged from 2.5 to 15 grams of AT and 5 to 15 grams of PT.

For the drug therapy, 14 studies used donepezil, one study used piracetam, and one study used memantine plus oxiracetam. Donepezil and memantine are standard treatments for AD, and piracetam and oxiracetam are currently being investigated as treatments for AD. The control groups received only the drug intervention, while the intervention groups received either the Chinese medicinal herbs or a combination of drug therapy and the Chinese medicinal herbs.

A subgroup analysis tested whether the duration of AT and PT administration (3 months vs. 4 months vs. 6 months) affected the outcomes.

Compared to conventional drugs alone, the combination of AT and PT with conventional drugs significantly improved cognition and functioning, as shown by improved MMSE scores, activities of daily living, and ADAS-C scores. When AT and PT were given alone, the outcomes were not significantly different from conventional drugs.

The subgroup analysis showed that the duration of administration did not influence the outcomes overall. A notable exception is the MMSE when AT and PT were given without drug therapy, which was improved after 6 months but not after 3 months of administration.

Adverse events were not significantly increased with the combination therapy of AT and PT plus drug therapy compared to drug therapy alone.

The researchers judged the overall quality of the evidence as very low to moderate.

The quality of evidence ranged from very low to low, suggesting a need for more high-quality research. The findings support the potential of AT and PT as an adjunctive therapy in AD treatment, but further research is needed to confirm long-term efficacy and safety.

Because the studies were conducted in China, this study’s findings might not be generalizable to other populations.