Scientists from the Jordan University of Science and Technology report that pomegranate juice at a dose of 1.5 mL per kg of body weight (or 105 mL for a 70 kg human) was associated with reductions in fasting glucose levels in type-2 diabetics.
Data published in Nutrition Research also indicated that there were no differences between male and female diabetics, although the effects were not observed in healthy people.
“Although these results are encouraging we must be cautious for the application of pomegranate juice use by type-2 diabetes patients,” wrote the researchers. “Additional clinical studies are needed to understand how the level of pomegranate juice affects blood glucose. To provide a more comprehensive understanding of pomegranate juice and diabetes, our laboratory is conducting clinical studies on the short-term effect of pomegranate juice on hormone levels in addition to insulin that are involved in glucose regulation.
“Studying the effects of pomegranate consumption (in a juice form) on the reduction of blood glucose levels in type-2 diabetes patients could lead to a dietary approach to control this disease,” they added. “Since there are many herbs and fruits that are easily available and of value in controlling this disease, this study may contribute to a better understanding and improved management of type 2 diabetes by the individual.”
According to the World Health Organisation (WHO), diabetes affects over 220 million people globally and the consequences of high blood sugar kill 3.4 million every year. If such statistics weren’t scary enough, the WHO is predicting deaths to double between 2005 and 2030.
The total costs associated with the condition in the US alone are thought to be as much as $174 billion, with $116 billion being direct costs from medication, according to 2005-2007 American Diabetes Association figures.
While many people around the world already consume pomegranate juice, it is not known how the antioxidant-rich beverage may influence blood sugar levels in diabetics and healthy people, explained the Jordan-based scientists in Nutrition Research.
To investigate this, they recruited 85 people with type-2 diabetes and assigned them to receive 1.5 mL of the juice per kg of body weight. Blood sugar and insulin levels, and beta cell function were assessed three hours after ingestion. (Beta-cells are found in the pancreas and their primary function is to store and release insulin.)
Results showed that pomegranate juice was associated with significantly lower fasting glucose levels (8.5 mmol/L) compared with the control participants (9.44 mmol/L). However, this result was an average for the whole cohort and about 20% of the participants did not experience this benefit.
“A statistical increase (P < 0.05) in beta-cell function was noted three hrs after pomegranate juice consumption, compared with the control,” reported the researchers. “In contrast, a statistically significant decrease (P < 0.05) in insulin resistance was observed among those patients three hrs after drinking pomegranate juice, compared with the fasted patients.”
Commenting on the potential mechanism, the researchers noted that the effects are most likely due to the antioxidant activity of the pomegranate juice, which helps to decrease oxidative stress.
Pomegranate, a rich source of antioxidants, has been linked to improved heart health, prostate health, and joint health. It is these antioxidants, and particularly ellagitannin compounds like punicalagins and punicalins, which accounts for about half of the fruit's antioxidant ability, that are reportedly behind the proposed health benefits.
Source: Nutrition Research
Published online ahead of print, doi: 10.1016/j.nutres.2014.08.003
“Fresh pomegranate juice ameliorates insulin resistance, enhances beta-cell function, and decreases fasting serum glucose in type 2 diabetic patients”
Authors: S.A. Banihani, S.M. Makahleh, Z. El-Akawi, R.A. Al-Fashtaki, et al.