Yet another benefit of maqui berry consumption has been revealed in an exploratory study in humans: extracts from the alleged superfruit lower fasting and postprandial glucose and insulin levels in prediabetics.
Maqui berry is an intensely purple wild berry, growing abundantly throughout parts of Southern Chile. Its purple color comes from a high concentration of antioxidant anthocyanins called delphinidins. While several reports show numerous health benefits of consuming delphinidins, a new study published in the journal BioMed Research International looks at the role of delphinidin in blood glucose regulation.
The study tested the effect of Delphinol – a proprietary maqui berry extract containing 25% w/w delphinidin glycosides and 35% total anthocyanins – on blood glucose and insulin levels under fasting and postprandial conditions, using a standard oral glucose tolerance test (OGTT). Forty-three prediabetic volunteers (24 women, 19 men) between the ages of 18 and 50 were recruited for the study. After an overnight fast, participants were given a single dose of Delphinol. An hour later, the subjects consumed a standard 75 g glucose solution. Blood glucose concentrations were measured before and 30, 60, 90 and 120 minutes following glucose consumption. Each volunteer underwent four OGTTs with different doses of Delphinol administered (60, 120 or 180 mg), and with at least one week of wash out period between successive OGTTs.
The authors found that Delphinol decreased fasting blood glucose levels in a dose dependent manner. In addition, Delphinol caused circulating levels of insulin to decline within 60 minutes of glucose intake. Some anomalies were noted: the lowest concentration of Delphinol tested (60 mg) resulted in a higher blood glucose level than those of the untreated controls at 60 minutes after OGTT. Two hours into the test, the 180 mg Delphinol dose had similar blood glucose levels as the untreated controls, but also showed lowest levels of insulin. The authors point out that a simultaneous reduction in both blood glucose and insulin levels have not been reported with Delphinol before, and merits further investigation.
The results are especially encouraging in light of the fact that Delphinol was able to decrease blood glucose and insulin levels in individuals with existing glucose intolerance and insulin resistance. However, an important caveat remains: the study cannot rule out glucose regulatory effects of other polyphenols present in the maqui berry extract. Future studies using pure delphinidin would be needed to confirm its beneficial role in glucose regulation.
Written By: Debapriya Dutta, PhD