Oral Aloe Vera for Treatment of Diabetes Mellitus and Dyslipidemia

Discussion

Five out of the seven studies that evaluated diabetes endpoints in humans showed significant reductions in fasting blood glucose after treatment with oral aloe vera in patients with diabetes or prediabetes;^{[21,22,24,25,28]} the remaining two studies reported a trend toward decreased blood or plasma glucose concentrations in the aloe-treated groups.^[26,27] Significant reductions in HbA_1c—up to 22.6% of baseline—were seen in all three studies that evaluated this measure.^[22,27,28] One of these studies reported improvements in fructosamine levels,^[27] suggesting an improvement in average blood glucose levels over time.

The demonstrated hypoglycemic effect of aloe vera in humans is consistent with results of animal studies, which have suggested that orally administered aloe vera gel is associated with an increase in plasma insulin.^[29]

Aloe vera's effects on lipid markers may be explained by its ability to suppress adipogenic gene expression.^[30] It has also been hypothesized that normalization of plasma lipid status by aloe vera may be mediated by the control of lipid metabolism, specifically increased clearance and decreased production of the major transporters of endogenously synthesized cholesterol and triglycerides.^[29] Lipid markers were evaluated in six human studies,^{[21,23–25,27,28]} and the five that reported triglyceride concentrations showed a reduction in this variable in patients treated with oral aloe vera.^{[21,23–25,28]}

The evidence for total cholesterol is conflicting, as three studies showed reductions in total cholesterol levels in aloe-treated patients^[21,23,27] and another three showed no change.^[24,25,28] A significant decrease in LDL cholesterol levels was seen in two studies,^[23,27] and Agarwal^[21] reported an increase in high-density lipoproteins (HDL) cholesterol levels to the normal range for 93% of his patients. However, none of these studies reported actual values for HDL cholesterol, so it is unclear whether the change (or lack thereof) in total cholesterol was driven by reductions in triglycerides or by changes in LDL cholesterol, HDL cholesterol, or both.

Although data on oral aloe vera for treating elevated blood glucose and normalizing lipid parameters in humans appear favorable, there are numerous and noteworthy limitations in the studies that hinder the clinical application of these results. Only two studies used the same formulation and dose of aloe vera.^[24,25] Therefore, differences in study results may be due to variations in aloe preparations and the part of the plant used.^[31] Importantly, 95% of the 5285 patients evaluated (in all studies) came from the study conducted by Agarwal,^[21] whose methods were poor. That study incorporated the husk of isabgol, a psyllium fiber, into the aloe bread mixture, which could have confounded the results. The effects of diet and exercise were not accounted or controlled for in any of the studies. The duration of treatment and the use or nonuse of concomitant oral hypoglycemics were also inconsistent among the studies.

Compliance was not adequately accounted for, and many of the studies did not provide a thorough description of baseline patient characteristics. One of the studies was not available in English,^[23] but we feel confident in the translation since another published report provides a similar summary of the data.^[32]

We do not favor or promote any particular product. We encourage patients who elect to use oral aloe vera to exercise caution in selecting a product. Certification by IASC would ensure the quality and purity of a product. The only product currently on the market that is described by its vendor as having "generally recognized as safe" status is Qmatrix (Aloecorp, Lacey, WA) in amounts up to 1200 mg daily.^[33] Since the studies we reviewed did not include a thorough safety evaluation, possible adverse effects should be considered. Aloe vera has known laxative properties, and its use may induce electrolyte imbalance that theoretically could present a risk for arrhythmia. In addition, abdominal pain and cramping, muscle weakness, and hypoglycemia are potential adverse effects.^[7] Although no changes in alanine transaminase or aspartate transaminase were reported in the three of the studies we included,^[25,27,28] two cases of acute hepatitis and one case of thyroid dysfunction after oral aloe use have been reported elsewhere.^[34–36] All but one of the studies in this review were 14 weeks or less in duration. The long-term safety and efficacy of oral aloe vera ingestion remain unknown.

Am J Health Syst Pharm. 2010;67(21):1804-1811. © 2010 American Society of Health-System Pharmacists, Inc.

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Cite this: Oral Aloe Vera for Treatment of Diabetes Mellitus and Dyslipidemia - Medscape - Nov 01, 2010.