Four dried fruits found to be low on glycemic index and a possible food source for people with diabetes

By Michael Oliveira

People with diabetes and followers of diets based on the glycemic index (GI) can enjoy dried fruits knowing they do not cause a blood sugar spike compared to starchy foods such as white bread, suggests a study published in the journal Nutrition and Diabetes.

The results of the study also suggest there’s potential for food manufacturers to develop low GI foods with reformulations that include dried fruit, say Dr. John Sievenpiper of St. Michael’s Hospital and researcher Cyril Kendall of the hospital’s Clinical Nutrition and Risk Factor Modification Centre.

The glycemic index was developed by Dr. David Jenkins of St. Michael’s in the early 1980s as a way of explaining how different carbohydrates affect blood glucose and to find out which foods were best for people with diabetes. Foods high on the GI index — such as white bread, most breakfast cereals, potatoes and rice — produce a spike in blood glucose and insulin, while the carbohydrates in low GI foods — including pasta, beans, lentils and certain whole grains such as barley and oats – are broken down more slowly, and cause more moderate increases in blood glucose and insulin.

This study compared the glycemic response of four dried fruits — dates, apricots, raisins and sultanas — versus white bread in 10 healthy participants and found the fruit had a lower GI and could lower the glycemic response of white bread through displacement of half of the available carbohydrate.

“People often worry about sources of sugar and fruits being one of them, but most fruit — in particular tender fruit — have a low glycemic index and what we’re showing here is dried fruit also have a lower glycemic index, so they don’t raise your blood sugar very much,” said Dr. Sievenpiper.

“This study finds people can use dried fruits as a low glycemic index food source to replace higher glycemic index foods, so as a snack food, for example. Dried fruit is going to be preferred to a grain-based cracker or snack.”

Dr. Sievenpiper said longer and larger randomized trials will be needed to confirm whether dried fruit can contribute to sustainable improvements in glycemic control, and whether other dried fruits have a similar GI.

This work received funding from the International Nut and Dried Fruit Council Foundation and the National Dried Fruit Trade Association. All study foods were provided by the National Dried Fruit Trade Association.

These papers are an example of how St. Michael’s Hospital is making Ontario Healthier, Wealthier, Smarter.

About St. Michael’s Hospital

St. Michael’s Hospital provides compassionate care to all who enter its doors. The hospital also provides outstanding medical education to future health care professionals in more than 29 academic disciplines. Critical care and trauma, heart disease, neurosurgery, diabetes, cancer care, care of the homeless and global health are among the Hospital’s recognized areas of expertise. Through the Keenan Research Centre and the Li Ka Shing International Healthcare Education Centre, which make up the Li Ka Shing Knowledge Institute, research and education at St. Michael’s Hospital are recognized and make an impact around the world. Founded in 1892, the hospital is fully affiliated with the University of Toronto.

St. Michael’s Hospital with Providence Healthcare and St. Joseph’s Health Centre now operate under one corporate entity as of August 1, 2017. United, the three organizations serve patients, residents and clients across the full spectrum of care, spanning primary care, secondary community care, tertiary and quaternary care services to post-acute through rehabilitation, palliative care and long-term care, while investing in world-class research and education.