Researchers conducted a review of previous research to determine the effects of dragon fruit in diabetes management.
Prediabetes and type 2 diabetes are diagnosed using blood sugar levels. A fasting plasma glucose (FPG) test measures blood sugar levels after approximately eight hours without eating. The two hours post-prandial glucose (2HPP) test measures blood sugar levels two hours after ingestion of a standardized glucose sample. The results of these tests are measured against a standard to determine diagnosis and next steps in the treatment plan.
Prediabetes is a precursor of type 2 diabetes. A person with prediabetes has high blood sugar levels but does not meet the threshold for a type 2 diabetes diagnosis. Management of these medical conditions includes a healthy diet, physical activity, weight management, medications, and natural health products.
Dragon fruit is high in antioxidants and animal studies have found that it may have blood-sugar lowering properties. In particular, the red flesh dragon fruit has been found to have higher antioxidants than the white flesh dragon fruit.
The objective of this study, conducted in Thailand and recently published in PLoS, was to review the available published data to assess the possible role of dragon fruit in diabetes, particularly prediabetes and type 2 diabetes. Data from four randomized controlled clinical trials were analyzed. All four trials had a control group, and the outcomes measured were the fasting plasma glucose (FPG) and two-hour post-prandial glucose (2HPP) levels. Patients with other diseases were excluded from the review.
In one study, researchers gave the participants between 60g and 600g of red flesh dragon fruit. One of the trials had pre-diabetic patients only. The prediabetes trial measured FPG with a sample size of 36 and the duration of treatment was four weeks. Three other trials comprised of type 2 diabetic patients only. The outcome measured in two of these studies was FPG, while the last study measured 2HPP. The sample sizes ranged from 28 to 51 participants and the duration of treatment was ten days, fifteen days, and four weeks. There were no adverse events documented by the studies.
The analysis of the results showed a significant decrease in FPG in the prediabetes study, but no significant reduction in FPG and 2HPP in the type 2 diabetes groups. Thus, so far in studies of dragon fruit in diabetes management, the results are mixed. Although dragon fruit has shown potential benefit in rat studies, more clinical trials are required to better understand whether dragon fruit can be used in the management of diabetes.
The sample sizes of the trials included in this analysis were small, the length of treatment in each trial was short and long-term safety was not measured. Another limitation mentioned by the article is the possibility that studies with negative results may not have been published. Until more information is available, dragon fruit may be considered as part of a healthy diet in managing prediabetes and type 2 diabetes.
Written by Anuolu Bank-Oni, Pharm.D,CDE
Reference: Poolsup N, Suksomboon N, Paw NJ. Effect of dragon fruit on glycemic control in prediabetes and type 2 diabetes: A systematic review and meta-analysis. PLOS ONE. https://doi.org/10.1371/journal.pone.0184577