Prof Jennie Brand-Miller answers your questions.
I find coconut water refreshing. But I have recently come across maple water. What is it? They say it is low GI. I am tempted to try it.
Maple water is the very same sap from the tree that they make the syrup from. It’s long been known as a refreshing drink straight from the tree when the sap is running in maple country, and not just in the US and Canada. In South Korea, drinking maple sap (“gorosoe”) is more than a springtime ritual, they have festivals and sap-drinking contests. Until recently, sap drinking had a very limited season as it could only be harvested during a narrow six-week window. According to the manufacturer of one of the launch brands, Kikki Maple Sweet Water®, “the sap is frozen to maintain its healthful benefits and maximize its fresh shelf life. At a local bottling plant, a hot fill process, with the liquid heated to just below 96 degrees Celsius, ensures that the drink remains below pasteurization temperature to preserve its purity, highlight the flavour and maintain healthful benefits. The product is then shipped, stored, and served chilled.”
What’s in it? Kiki has about 60 calories (250 kilojoules) per 10 fluid ounce (300ml) serving. Its light maple sweetness comes from the 2–3 percent concentration of sugars in the sap, but that still gives you around 15g or 3 teaspoons of sugar (sucrose, glucose and fructose) in a serve – as does coconut water, if you want a comparison. There are claims that it is a low glycemic drink. But there is no actual GI value for it at present, as it has not been GI tested – I assume the claim is based on the GI value for pure maple syrup (GI 54). This is a hard one to guesstimate, and it would be good to see it GI tested (ditto coconut water). If it is only 2–3% sugars, then it empties faster from the stomach (like watermelon), so it could have a higher GI than maple syrup, depending on the balance of the sugars. Even so, the glycemic load would be low unless you drank several cups at a sitting as there is less sugar (carbohydrate) in it. There are other claims about its nutritional benefits including vitamins, minerals and polyphenols. We still think that it’s one for the occasional category, and not for everyday hydration. It’s the calories that not only count, but add up. To quench your thirst, it’s hard to beat water.
What about coconut water?
We were recently asked about how healthy coconut water really is. We haven’t reviewed it, but Catherine Saxelby over at Foodwatch has. You can check out her report HERE.
The latest GI values from SUGIRS
Also called: Brown rice syrup, rice malt syrup This is a mild-flavored, malted-grain sweetener that dissolves easily and is used in drinks and dressings, in baking and as a topping for cereals, waffles and pancakes. It is about one-third as sweet as regular sugar (sucrose) and is made by fermenting whole brown rice with enzymes that break down the natural starch content of the grain. The sugar composition of the final product is around 45% maltose, 3% glucose, and 52% maltotriose (a trisaccharide consisting of three glucose molecules joined together).
GI testing by an accredited laboratory
- Glycemic index = 98
- Available carbohydrate per 5g serving (1 level teaspoon) 4g
- Glycemic load per 5g serving (1 level teaspoon) = 4
- Glycemic load per 10g serving (2 level teaspoons) =8
- Glycemic load per 15g serving (1 level 15-ml tablespoon) = 12
- Glycemic load per 20g serving (1 level 20-ml Australian tablespoon) = 16
Dr Alexandra Jenkins
Glycemic Index Laboratories
20 Victoria Street, Suite 300
Toronto, Ontario M5C 298 Canada
Phone +1 416 861 0506
Research Manager, Sydney University Glycemic Index Research Service (SUGiRS)
Human Nutrition Unit, School of Molecular and Microbial Biosciences
NSW 2006 Australia
Phone + 61 2 9351 6018
Fax: + 61 2 9351 6022