Sweetening the breakfast oats or baking banana bread used to be simple – just use a little sugar or honey. But sweeteners have become more complicated as more sugar alternatives appear on the shelves of health food stores and supermarkets. Along with sweet syrups like agave and brown rice syrup, there’s now xylitol, dextrose, coconut palm sugar and stevia.
What they all have in common is a reputation for being somehow healthier than Australia’s standard sweetener, cane sugar – but for different reasons.
Those wanting sweetness with fewer kilojoules might go for stevia, for instance, while someone wanting a less refined sweetener might choose coconut palm sugar. But if you want a sweetener with a low Glycaemic Index (GI) – meaning it raises blood glucose (blood sugar) slowly rather than rapidly – you might use agave syrup. This can have a GI as low as 10 to 19, compared to sugar which is 68.
For people keen to avoid fructose – the type of sugar that makes up 50 per cent of cane sugar – dextrose is often promoted as healthier. Also known as glucose, dextrose is what’s left when you remove fructose from cane sugar.
Here’s how some of these sweeteners stack up:
Coconut palm sugar. From the sap of coconut palm flower buds, this looks a bit like a less refined sugar but has a richer taste. Similar to cane sugar because it consists of 75 per cent sucrose (the same sugar as in sugar cane) which in turn is made up of 50 per cent fructose and 50 per cent glucose. Although it’s promoted as having a lower GI, there’s no reliable data to back this up, says Dr Kate Marsh, an accredited practising dietitian and author of TheLow GI Diet for Polycystic OvarySyndrome and The Low GI Vegetarian Cookbook.
Brown rice syrup. Made by fermenting whole brown rice, it consists of three types of sugar – maltose, maltotriose and glucose – and is often recommended for people avoiding fructose. “But it’s still basically sugar and high in carbs,” Marsh points out. “It also has a high GI of 98 which means it will raise blood glucose and insulin levels more than regular table sugar. It’s also less sweet so you may need more to get the same level of sweetness.”
Agave syrup. From the same plant that gives us tequila, this is mostly fructose and because fructose has less of an effect on blood glucose levels it has a low GI. However the high fructose content could be a problem for anyone who has problems with fructose malabsorption. This is where the gut has difficulty absorbing fructose and any fructose left lingering in the bowel ferments, causing gas.
Dextrose. Available as a powder, dextrose can be used for baking or for making fructose-free desserts. (Although many recipes for these are made with white flour – and you have to wonder what’s healthy about that). “It’s a highly processed carb with a very high GI of 100,” Marsh says.
Xylitol. Belongs to the family of sugar alcohols (other members include sorbitol and mannitol). They are derived from plants and despite the name don’t contain alcohol. Although you’re more likely to find sugar alcohols in manufactured foods, you can buy xylitol in the health food aisle and it can be used in baking. “Its benefits are a low carbohydrate content and very low GI and unlike regular sugar it’s tooth friendly,” Marsh says. “But it’s not fully broken down during digestion so it has a laxative effect if you consume a lot. It would also be a problem for people on a low FODMAP diet – FODMAPs are a group of carbohydrates, including sugar alcohols, that can cause digestive problems including wind, bloating and diarrhoea in some people.”
Stevia. A plant-based sweetener with zero kilojoules that’s so intensely sweet (about 290 times sweeter than sugar) that it takes only a tiny amount to sweeten food, although it has an odd after-taste. However some stevia products are a mix of stevia with erythritol, which is another sugar alcohol, Marsh says. “This means it can have a laxative effect if you eat a lot – although it has less of a laxative effect than other sugar alcohols.”
As for Marsh’s advice when clients ask for a healthier sweetener, she suggests using other ingredients such as fruit, dried fruit, carrot, pumpkin, and spices like cinnamon, ginger and vanilla with smaller amounts of sugar as needed.
“Otherwise I’d tend to recommend lower GI sweeteners such as floral or bush honeys (e.g. yellow box), pure maple syrup, which is mostly sucrose with small amounts of glucose and sucrose and similar to cane sugar, or agave – but in small quantities.”