Posted by kathryn in A Balanced Diet, Carbohydrates and Q & A Thursday

Joanne has also asked about fructose:

What are you views on fructose, as opposed to sucrose or glucose? I understand fructose has a lower GI, and in addition, is about twice as sweet as sucrose, so less can be used for the same taste (for example, when adding to coffee). This suggests to me that fructose is a healthier alternative to table sugar.

But I’ve read that over-consumption of fructose has bad effects including damaging the liver, and that it doesn’t produce the same feeling of satiety as glucose. If overconsumption of fructose is a problem, how much is too much?

Fructose is a sugar and is found in fruit, honey and some vegetables. While it provides the same amount of kilojoules by weight, it’s sweeter than sugar, so less is used. One of the big drawcards is, fructose has a very low glycemic index (GI) of 19.

Firstly, I should note, fructose is rarely used here in Australia, so I’m almost certainly not up-to-date with its health effects. Secondly, in all the concern about whether fructose is okay, we are talking about the extracted sweetener . This discussion does not relate to fruit and vegetables.

Despite it’s low GI, there is a concern that fructose may be involved in the development of Syndrome X (or metabolic syndrome). At present however, there is conflicting evidence on this point.

A lot of the concern around fructose is focused on high-fructose corn syrup (HFCS), a sweetener which is used extensively in the US. HFCS is manufactured from corn starch and despite it’s name, the final product is roughly 50 percent fructose and 50 percent glucose. The GI of HFCS is about the same as that of normal sugar (ie about 60). Huge amounts of HFCS are used in the US and it’s been strongly linked-in with the obesity debate.

To be honest, I would still keep on using normal sugar – I think there is enough concern about fructose to limit it’s use. It’s boring, but my belief is the key lies not in finding new, lower kilojoule ways of sweetening our foods. Instead, we need to eat a bit more fruit and vegetable, cut the sweet stuff back to occasional treats and move more.

If any of my US readers can add to this, I’d be very grateful. I’d also love links to any current information, or views on what’s happening in the States.

12 July, 2007