Aloe vera shows significant glucose lowering properties in meta-analysis

A meta-analysis suggests that aloe vera may have significant glucose-lowering properties.
Aloe vera is a plant that is native to Africa and certain Indian Ocean islands but can be grown anywhere with a suitable tropical environment. Aloe vera has shown glucose-lowering effects in smaller trials so the researchers, from the David Grant Medical Center, California, decided to run a meta-analysis to review the effects of aloe vera over a larger number of participants.
The researchers took care to choose only studies that met a number of quality factors including only involving clinical trials that were being placebo or active controlled. From an initial 205 aloe vera studies that were identified, nine of these met the qualifying criteria for inclusion in the meta-analysis.
The results of the study showed that aloe vera decreased fasting blood glucose levels by 2.6 mmol/l (47 mg/dl) and decreased HbA1c levels by 12 mmol/mol (1.1%). The researchers noted that participants that had very high fasting blood glucose levels (over 11.1 mmol/l or 200 mg/dl) experienced the greatest benefit from aloe vera.
The researchers cannot say with any certainty why it is that aloe vera may result in the significant improvements in blood sugar levels. One note that the authors drew upon is that ingestion of aloe vera can lead to gastrointestinal effects such as abdominal cramping and diarrhoea which may have had consequences on food intake and/or digestion that could play a part in the reduced glucose levels.
Whilst the nine studies passed their quality criteria, the researchers highlighted that they still included a number of limitations such as short duration of study and small sample size (a small number of participants in individual trials).
The meta-analysis shows significant positive results for aloe vera but the researchers conclude that: “further clinical studies that are more robust and better controlled are warranted to confirm and further explore these findings.”
The study is published in the Journal of Alternative and Complementary Medicine.