Studies have confirmed that the date fruit contains a high level of carbohydrates, proteins, and dietary fiber. The fruit also contains considerable amounts of potassium, calcium, and magnesium. Date fruits also have polyphenols and flavonoids. These are compounds that play a role in reducing blood glucose levels. The seeds of the date palm fruits, on the other hand, were found to have high levels of different fatty acids. These include oleic, linoleic, lauric, palmitic, and stearic acids. Overall, their composition makes it a nutritious snack that may have the additional benefit of controlling blood glucose to help treat diabetes.

Polyphenols are compounds that have a strong antioxidant action. These compounds are also thought to inhibit certain enzymes, such as α-amylase and α-glucosidase, which play a role in increasing blood glucose levels after a meal. Therefore, inhibiting these enzymes could potentially help control blood sugar levels.  Flavonoids, on the other hand, are thought to help stimulate β-cells in the pancreas. This in turn would stimulate the production of more insulin. The produced insulin would then bring down the level of glucose in the blood. 

Diabetes occurs when blood glucose levels are too high. Normally, glucose levels in the blood increase after a meal. In nondiabetic individuals, β-cells in the pancreas are stimulated and the hormone insulin is released. Insulin would then help the body utilize glucose for energy. In individuals with type 1 diabetes, the underlying issue is that their bodies are not able to make insulin. In those with type 2 diabetes, their bodies are able to produce insulin. However, they may not be making enough of it or they are unable to utilize the hormone properly. When the body is unable to use insulin to get energy from glucose, there is an accumulation of glucose in the blood. This is called high blood sugar and is also referred to as hyperglycemia. 

Studies have shown that date palm fruits have anti-hyperglycemic activity. This means that they can help decrease glucose levels in the blood. They can also help in increasing insulin activity in the body.  

For a month, one study administered date fruit extracts to rats that had a drug-induced form of diabetes. Results showed that their blood glucose levels were reduced significantly and the concentration of insulin had increased. The date fruit extract had also shown improved insulin secretion when compared to an untreated diabetic control group. It is speculated that the flavonoids in the date palm fruit helped increase the number of β-cells in the pancreas. This in turn helped stimulate insulin secretion. 

In another study, rats were given date fruit pulp for 14 days. They were found to have reduced glucose levels in the blood when compared to a control group. The polyphenols in the date fruit were thought to have caused slow gastric emptying (a step in digestion). This then resulted in reduced glucose in the blood.

Other studies were conducted on hyperglycemic rats and those with normal blood glucose (control). They found a significant improvement in glucose levels in the hyperglycemic rats after being treated with date fruits. Researchers hypothesized that the fiber in the date extract resulted in reduced absorption of carbohydrates during digestion. This in turn would have affected a glucose transporter called GLUT 4, which is responsible for how much glucose enters cells of muscles and fat. GLUT 4 is also regulated by insulin levels in the body. In addition, the polyphenol compounds found in dates are thought to have inhibited α-amylase and α-glucosidase. These enzymes play an important role in breaking down carbohydrates and intestinal absorption.

In another laboratory study done over the course of 28 days, scientists found a decrease in the blood glucose levels of subjects. There was also an improvement in the secretion of insulin. They hypothesized that genistein, a type of flavonoid found in dates, prevented β-cells from undergoing apoptosis (programmed cell death). This in turn increased the number of β-cells which then resulted in an increase in insulin secretion.

Individuals with chronic diabetes are at an increased risk of developing damage to certain organs. Some studies show that date fruit extract may help protect against certain damages. One laboratory study showed that extracts of certain date fruits contained protective factors against the onset of diabetic cardiomyopathy, a diabetes-related heart disease. 

Diabetic individuals are often prone to developing neuropathy, which refers to damages to the nerves over time. A six-week laboratory study in diabetic rats found that neuropathy was improved in subjects who had been administered date fruit extract. The flavonoids and vitamin C found in date fruits have antioxidant and free radical scavenging properties. These compounds are known to prevent oxidative stress that causes neuropathy. Furthermore, they were also observed to aid in producing nerve growth factors that help support neurons. Their properties may further offer more protection against developing neuropathy. Incidentally, vinegar derived from the date palm fruit has also been shown to be effective in improving liver function in patients with diabetes.