A new study conducted at the Illinois Institute of Technology in Chicago found eating raspberries is beneficial in controlling blood glucose in those who are pre-diabetic or have issues with insulin resistance. The results published in the journal Obesity showed as raspberry intake increased the amount of insulin needed to manage blood sugar decreased.
The purpose of the study was to investigate the effects of eating raspberries on a group of people who were already showing signs of insulin resistance and were at risk for diabetes because of their weight.
The Centers for Disease Control and Prevention (CDC) says as of 2015 an estimated 34 percent of adults in the U.S. are pre-diabetic. That makes them susceptible for a number of adverse health conditions including the development of type 2 diabetes, cardiovascular disease and Alzheimer’s disease.
Researchers used a control of metabolically healthy individuals and combined them with the obese subjects. They were then randomly assigned to one of three groups and had their blood monitored for several days.
The study participants were given identical high carbohydrate/moderate fat breakfasts in terms of calories and macronutrients on three separate days. The only difference is one group was given no raspberries. The other groups were given either a one-cup serving of frozen raspberries with their meal or two cups of frozen raspberries.
"People at risk for diabetes are often told to not eat fruit because of their sugar content. However, certain fruits—such as red raspberries—not only provide essential micronutrients, but also components such as anthocyanins, which give them their red color, ellagitannins and fibers that have anti-diabetic actions," said Britt Burton-Freeman, Ph.D., director, Center for Nutrition Research at Illinois Tech. "For people who are at risk for diabetes, cardiovascular disease and other health risks, knowing what foods have protective benefits and working them into your diet now can be an important strategy for slowing or reversing progression to disease."
The pre-diabetic and insulin resistant group (PreDM-IR) that consumed raspberries regardless of amount significantly reduced their two-hour insulin area under curve (AUC), which means their body required less insulin. The group that consumed the two cups of raspberries had reduced peak insulin, peak glucose and two-hour glucose versus the control group.
"Our findings suggest that red raspberries aid in postmeal glycemic control in individuals with PreDM-IR, reducing glycemic burden with less insulin, which may be related to improved tissue insulin sensitivity," said Burton-Freeman.