This week I’m looking in-depth at low-carb natural sugar substitute, Xylitol.
Given what we all know now, about sugar being the devil, I think I am fortunate, on balance, not to have much of a sweet-tooth. It’s mostly savoury delectables like big, fat, triple-cooked chips, say, that I find almost impossible to resist.
Of course, potatoes, as a starchy carbohydrate, are predominantly sugar in a different form anyway. Potatoes have a very high Glycaemic Index (GI) score, and therefore potentially a big impact on blood sugar (depending on the volume eaten and the GI of the other foods they’re eaten with). But at least I don’t usually tend to go for things containing much of what nutritionists sometimes call ‘extrinsic’ or ‘free’ sugar – that is, added sugar, and sugar naturally present in fruit juice, syrups and honey.
When I do want something sweet, though, then this week’s low-carb swap, xylitol, is one of my favourite low-carb cooking ingredients. I do use a couple of other natural sugar substitutes too, and will write about those another time. But I wanted to write about xylitol now, as it will turn up as an ingredient in some of the low-carb swap recipes for cakes etc. that I will post in the near-future.
Advantages of xylitol as a sugar substitute
For me personally, I find xylitol’s advantages to be:
• It is both lower-carb, and has fewer calories, than sugar (see below).
• Despite the scientific-sounding name, which may make you think xylitol is an artificial sweetener, it most definitely isn’t. It is a completely natural substance, and does not contain artificial chemicals. In its optimum form, it is usually derived from trees like birch (the prefix ‘xyl-‘ is derived from the Greek word for wood).
• It’s granulated, looks exactly like white sugar, and can be used spoon-for-spoon and weight-for-weight in drinks and recipes exactly like sugar. So there’s no need for any tricky and inexact recipe conversions.
• In cooking, I’ve found that xylitol mostly behaves like sugar, so the end-results tend to be the same, or at least very similar. You just can’t hard-caramelise it, so you can’t use it on top of a crème brûlée. And you can’t use it in leavened bread-making, as yeast can’t feed on it.
• I think xylitol has a really pleasant taste which is very similar indeed to sugar, although a little more mildly sweet. If you were to eat it neat(!), it feels a little cooling in the mouth.
• There is no nasty bitterness or synthetic taste, as there are with artificial sweeteners.
• It’s not only better for your oral health than sugar, because it doesn’t cause tooth decay – but it also has actively positive benefit and an antibacterial effect in the mouth. There are a whole load of scientific reviews (e.g. this in 2017) that conclude, cautiously, that the role xylitol can play in the prevention of dental caries is proven. This is why xylitol appears in many chewing gums, toothpastes, and mouthwashes.
What is Xylitol?
Xylitol is a type of polyol, classed as a sugar alcohol (you may be more familiar with its family members, sorbitol and maltitol, on ingredients labels). But this chemical designation is a bit confusing, as it’s neither sugar, nor alcohol, in the way that we usually understand those terms for culinary uses.
Polyols, and therefore sugar alcohols including xylitol, are actually a form of carbohydrate that we can’t digest efficiently. A more familiar illustration may be for fibre, which is also a carbohydrate that we can’t digest efficiently (although it is not a polyol), and which therefore passes through us largely unabsorbed. So, similar to fibre then, we absorb fewer calories and carbs from xylitol, than we do from other types of carbohydrate like normal table sugar, which are fully digested.
I use a brand of xylitol called Total Sweet, originally just because it happens to be easy to find in the UK in supermarkets, health food shops, and online. Since I started using it, though, I have also discovered that it professes to be a company with ethics quite similar to mine, including having a webpage listing a large number of scientific articles to back-up some of the health claims for xylitol. The product is apparently made from sustainable, non-GMO, Finnish beech and birch wood. It is also pure xylitol, not a mix including less-desirable fillers. But there are certainly other available brands too, if you want to shop around.
Nutrient count: Xylitol vs. Sugar
|Per 100g serving||Xylitol||Sugar (sucrose)|
|– of which sugars||0||100|
|– of which polyols||100||0|
Source: verified information from the MyFitnessPal Database and Total Sweet nutrition information
At first glance, the table above appears to indicate that xylitol and sugar have the same amount of carbs, and that it’s a very high number at that. They do, but the crucial difference is the type of carbs, which is why many nutritional labels have an ‘of which sugars’ sub-category.
So in fact these numbers show that 100% of the carbs in xylitol are polyols, which, as we’ve already seen, behave differently to the carbs in sugar which are – well – 100% sugar of course. Xylitol apparently has less than half the ‘net’ or ‘available’ carbs of sugar, and at 240Kcal per 100g, you’re saving 40% over sugar in terms of calories.
Xylitol has a GI value around 7 against sugar’s 65, so it is classed as low GI, while sugar is high GI. This all means that xylitol only raises blood sugar very slowly – while conversely, sugar can cause a fast blood sugar spike. That triggers an insulin rush in the body which, because of the way insulin works, means the greater number of calories in sugar are also more likely to be laid down as fat – or to contribute to developing insulin resistance – than the lower number of calories in xylitol. Therefore, it is often included in foods marketed as helping to manage type 2 diabetes. (However, l see that the charity Diabetes UK don’t recommend xylitol. They seemingly prefer to recommend artificial sweeteners as they feel that – in off-the-shelf products at least – these tend to be included in products which are lower overall in calories and fat).
Disadvantages of Xylitol
• Xylitol may well not be suitable for people who have irritable bowl syndrome (IBS), and in particular those who have chosen to follow a low-FODMAP diet. Low-FODMAP eating involves exclusion from the diet – or at least restriction – of groups of short-chain carbohydrates, which are all either slowly absorbed, or not digested, in the small intestine. Collectively, they are known as Fermentable, Oligosaccharides, Disaccharides and Monosaccharides and Polyols (FODMAPs). Following a low FODMAP diet can significantly reduce abdominal symptoms associated with IBS, and is often now considered a front-line therapy. So IBS sufferers, bear this is mind in your decision about whether to include xylitol in your diet. And you may also wish to look at your existing diet and remove it e.g. by ensuring you aren’t chewing xylitol gum. And if you’re diabetic and getting IBS or diarrhoea, then you might also want to review the volume of polyol sugar substitutes in your diet, and try toning it down a bit.
• For similar reasons, xylitol can have a laxative effect if you eat a lot of it. I’ve never had any problems personally. But if you do, it’s suggested not to have more than 10g per 10kg of body weight per day, and to work up to that amount gradually. If you weighed 10st/63kg, say, that’s 60g of sugar substitute, which seems to me not an overly-restrictive daily amount.
• Because of the lack of research, it isn’t recommended to use xylitol while pregnant or breastfeeding, or to give it to very young children
• DON’T give anything containing xylitol to your pets. It is toxic to dogs, may at least make them sick, and could even lead to death. (Because of xylitol’s toxicity for dogs, it had also been widely assumed that it was toxic to cats, but it seems that view has become discredited).
• It’s more expensive than sugar. As I write this in June 2017, it costs about £9.99 per kg in the UK, while sugar is around £1.10. So, as with so many dietary choices, it’s a question of weighing up all the alternatives, their availability, your own economic situation, and the priority or not you place on healthy eating and/or including a healthier sugar substitute in your diet.
• It’s a refined sweetener, so like sugar, it is empty calories. But it does contain fewer of them than sugar
• It’s lower-carb and lower-calorie than sugar, but not no-carb and no-calorie like artificial sweeteners. Again, it’s down to personal choice. I’m lucky enough not to have any IBS problems. And the fact that I don’t fancy very sweet things so often, means I can have fewer of them in my diet, but I can afford to make them healthier and tastier, with a few extra calories, when I do. That means I’m not consuming too much xylitol, and in the context of my overall diet, using xylitol doesn’t work out to be too expensive. But of course at the end of the day, it’s entirely up to you to use the information here, or not, to decide whether using xylitol fits with your own health and lifestyle.