GI Values Update

Update on Dried Dates
It would appear that the GI value of dried dates could vary significantly depending on the variety (and there are approximately 600 varieties). When dried dates were first tested their GI value was 103. This high value was puzzling and was rechecked a number of times. It may be that the amount of carbohydrate per serve on the packaging label was incorrect. A team in the Faculty of Medicine and Health Sciences at UAE University has recently tested the khalas variety of dates and found that the average GI value was 39.

• Khalas dried dates GI 39 (average)

—Reported in the European Journal of Clinical Nutrition (2003) 57 427–430 (Miller CJ, Dunn EV, Hashim IB. The glycaemic index of dates and date/yoghurt mixed meals. Are dates ‘the candy that grows on trees’?)

The Popular Potato
Roots and tubers are the third largest carbohydrate source in the world with potatoes the most popular—half of all root crops consumed. The yearly per capita consumption of potatoes in the US has more than doubled since 1970. In fact, Americans, for example, consume more potatoes than any other vegetable.

The GI value of potatoes can vary significantly depending on variety and cooking method (GI 56 to 89) according to University of Toronto researchers reporting in the Journal of the American Dietetic Association. Their study found that precooking and reheating potatoes or consuming cold cooked potatoes (such as potato salad) reduces the glycemic response. The highest glycemic index values for potatoes were found in potatoes that were freshly cooked and instant mashed potatoes.

• Boiled red potatoes served cold GI 56
• Roasted California white potatoes GI 72
• Boiled Prince Edward Island potatoes GI 72
• Baked US Russet potatoes GI 77
• Instant mashed potato GI 88
• Boiled red potatoes served hot GI 89

—Reported in the Journal of the American Dietetic Association. 2005;105:557-562 (Fernandes G, Velangi A, Wolever T. Glycemic index of potatoes commonly consumed in North America)