GI Update

The latest GI values with Fiona Atkinson

New low GI breakfast cereal
‘It’s good to have some low GI flaked cereals available on the market that taste great and are nutritionally sound,’ says SUGiRS manager Fiona Atkinson. ‘GI testing the Goodness Heart 1st cereal was really easy as the volunteers loved the toasted flakes, oats and dried cranberries.’

Goodness Heart 1st, Goodness Digestive 1st and Goodness Protein 1st are flake type breakfast cereals manufactured with the low GI flour power of BARLEYmax (see GI News May 2006) – a non-genetically modified barley grain with enhanced nutritional benefits developed by Australia’s CSIRO.

We have yet to taste them here in the editorial office, but we have heard enthusiastic reports such as: ‘stays crunchy’, ‘doesn’t go soggy with milk’, and ‘bloody delicious’. According to the ingredient panel they contain rolled barley flakes, golden syrup and (Digestive 1st – sultanas, diced apple and honey) and (Protein 1st – soy flakes and amaranth).
So how does a bowl of these cereals (45 g or 1½ oz a serving) rate in the GI stakes (served with low fat milk)?

Goodness Heart 1st – GI 46 (available carbs 20 g)
Goodness Digestive 1st – GI 39 (available carbs 18 g)
Goodness Protein 1st – GI 36 (available carbs 17 g)

For more information: goodnesssuperfoods.com.au

Fruit juice Q&A with Prof Jennie Brand-Miller

‘Does fruit juice have a low GI? If people are craving a sweet drink, are they better off drinking a small glass of fruit juice than a non-diet soft drink, cordial or sports drink?’
Yes, fruit juices have a low GI in most cases (40–50) and they contribute valuable micronutrients that you won’t find in alternative beverages. Some fruit juices are not low GI, e.g. Ocean Spray cranberry juice/drinks, which are around 60. Most non-diet soft drinks are in the range 60–70. Sports drinks can be 70–80.

‘Does the very high amount of fructose in fruit juice have any effect on the release of glucose?’
When it comes to any sugary product (natural or otherwise), you have usually have a mixture of sucrose, glucose and fructose. Sucrose is digested quite quickly to glucose plus fructose before absorption. While glucose is generally absorbed rapidly, it can be slowed by acidic solutions (e.g. all fruits are acidic). Fructose absorption is a much slower process and doesn’t raise glycemia anyway. The high proportion of fructose in fruit and fruit juice is one reason why they have a low GI. But it’s not the only reason. Very large amounts of fructose (70 g a day or more) from any source can have adverse effects on blood lipids (fats). The old adage applies: enjoy in moderation.

‘Are there any advantages to drinking fruit juice, or should people always opt for the whole fruit? So long as people limit themselves to one small glass a day, can 100% fruit juice be part of a healthy diet, or should people consider fruit juice an occasional treat?’
Opt for whole fruit if you want to feel fuller (satiated) for a longer time. but as long as people limit themselves to one small glass a day, 100% fruit juice can be part of a healthy diet. I can’t think of any advantage of drinking fruit juice (I avoid them myself). It’s much more satiating to eat the same portion as the whole fruit. But I’m pragmatic too … if there’s no fruit on hand, then fruit juice is better than no fruit, and superior to a soft drink.

Bear in mind that some researchers believe that sugars in solution (whether soft drinks or fruit juice) bypass the satiety centre in the brain, i.e. we don’t register them properly and therefore don’t take their calories into proper account. I’m actually quite sceptical of this idea. Milk is a solution of sugar but babies seem to grow at the right rate.

GI testing by an accredited laboratory
North America
Dr Alexandra Jenkins
Glycemic Index Laboratories
36 Lombard Street, Suite 100
Toronto, Ontario M5C 2X3 Canada
Phone +1 416 861 0506
Email info@gilabs.com
Web http://www.gilabs.com/

Australia
Fiona Atkinson

Research Manager, Sydney University Glycemic Index Research Service (SUGiRS)
Human Nutrition Unit, School of Molecular and Microbial Biosciences
Sydney University
NSW 2006 Australia
Phone + 61 2 9351 6018
Fax: + 61 2 9351 6022
Email sugirs@mmb.usyd.edu.au
Web https://glycemicindex.com/

New Zealand
Dr Tracy Perry
The Glycemic Research Group, Dept of Human Nutrition
University of Otago
PO Box 56 Dunedin New Zealand
Phone +64 3 479 7508
Email tracy.perry@stonebow.otago.ac.nz
Web glycemicindex.otago.ac.nz

See The New Glucose Revolution on YouTube