Sorbitol and Xylitol - Are they Good Sugar Replacements? | Chris Kresser

Are Xylitol, Sorbitol, and Other Sugar Alcohols Safe Replacements for Sugar?

by Chris Kresser

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sorbitol, xylitol, is sorbitol safe
Sorbitol and xylitol are both sugar alcohols. Are they safe sugar alternatives? istock.com/grafvision

In the last article of this series I discussed artificial sweeteners, and gave you my take on whether you should include them in your diet. This week, I want to talk about sugar alcohols, which are another popular low-calorie sugar substitute.

Xylitol is the most popular and most extensively researched, so I’ll focus my discussion on it, but the general takeaway of this article applies to other sugar alcohols as well, such as sorbitol and erythritol.

Xylitol and sorbitol are commonly used as sugar replacements, but are they safe? Here’s what you need to know!

What Exactly Are Sugar Alcohols?

Sugar alcohols are a type of ‘low-digestible carbohydrate,’ a category that also includes fiber and resistant starch. Sugar alcohols occur naturally in many fruits and are also known as ‘polyols,’ which you may recognize as a FODMAP.

Unlike artificial sweeteners, sugar alcohols aren’t completely calorie-free, because we are able to digest and absorb them to some extent. The absorption rate varies among sugar alcohols, from about 50% for xylitol to almost 80% for sorbitol, depending on the individual. (1) Erythritol is almost completely absorbed, but is not digested, so it provides almost no calories. (2)

Compared with artificial sweeteners, sugar alcohols have very few safety and toxicity studies, and are generally accepted as safe. (3) In one long-term human study, 35 participants consumed xylitol as their primary dietary sweetener for two years, and no adverse effects other than GI distress were observed, and GI symptoms dissipated after the first couple months. (4) The amount of xylitol consumed during this trial regularly exceeded 100g per day, often going over 200g per day, depending on the participant.

Metabolic Effects of Sugar Alcohols

Sugar alcohols are a popular choice for weight loss due to their reduced calorie content, and for diabetics due to their low glycemic index. There’s not nearly as much research on the metabolic effects of sugar alcohols as there is on artificial sweeteners, but the evidence we have suggests that sugar alcohols are at least harmless, and possibly beneficial.

For the most part, sugar alcohols cause no appreciable changes in blood glucose or insulin in humans, and sorbitol and xylitol have not been found to raise blood glucose following consumption. (5) In diabetic rats, 5 weeks of xylitol supplementation (as 10% of their drinking water) reduced body weight, blood glucose, and serum lipids, and increased glucose tolerance compared with controls. (6) Two other rat studies also found that xylitol-supplemented rats gained less weight and fat mass compared with control rats, and had improved glucose tolerance. (7, 8)

Because sweetness does not predict caloric value in sugar alcohols, one might expect that they would cause the same ‘metabolic confusion’ that is seen with noncaloric artificial sweeteners. Unfortunately there isn’t enough evidence to form a conclusion about this, but my feeling based on what I’ve read is that this isn’t a significant issue for sugar alcohols.

For one, sugar alcohols aren’t ‘intense sweeteners’ like artificial sweeteners, which are hundreds of times sweeter than sugar. In fact, many are less sweet than sugar. Also, sugar alcohols do provide some calories, so there’s not as much of a discrepancy between the caloric load your body expects and the caloric load it actually gets.

Does Xylitol Prevent Tooth Decay?

The most well-known health benefit of xylitol is easily its effect on dental health, and evidence for xylitol’s ability to prevent tooth decay is pretty robust. (9) A couple trials have found xylitol to be more effective at preventing cavities than fluoride, and benefits of xylitol consumption have even been observed in children whose mothers chewed xylitol-containing gum. (10) Unsurprisingly, the most drastic effects are observed when xylitol replaces sucrose in either the diet or in chewing gum, but significant reductions in cavities have been observed when xylitol is simply added on top of a normal diet as well. (11, 12)

Although some effects of xylitol are undoubtedly due to nonspecific factors such as increased saliva production or the replacement of sugar, it does appear to have specific properties that support dental health. Xylitol is not fermentable by common plaque-forming oral bacteria like sugar is, so it doesn’t provide a food source. (13) Additionally, xylitol actively inhibits the growth of these bacteria. It also forms complexes with calcium, which may aid in remineralization.

Sugar Alcohols and Digestive Health

While sugar alcohols appear to be safe and potentially therapeutic, they are also notorious for causing digestive distress. Because sugar alcohols are FODMAPs and are largely indigestible, they can cause diarrhea by pulling excess water into the large intestine.

The fermentation of sugar alcohols by gut bacteria can also cause gas and bloating, and sugar alcohols may decrease fat absorption from other foods. (14, 15) However, most evidence indicates that people can adapt to regular sugar alcohol consumption, and the adverse GI effects reported in studies tend to fade after the first month or two.

Erythritol is probably the best-tolerated sugar alcohol, and a few human trials have found that if the amount of erythritol is gradually increased and doses are spread throughout the day, many people can tolerate large amounts (up to1g/kg of body weight) of erythritol without GI distress. (16, 17) The average tolerance for xylitol and sorbitol is lower; most study subjects could tolerate about 30g per day without a problem, but significant adaptation was necessary to increase xylitol content in the diet. (18)

A few studies indicate that sugar alcohols may have a prebiotic effect. This isn’t too surprising, considering the prebiotic effects of other low-digestible carbohydrates such as fiber and resistant starch. Animal studies have found that xylitol causes a shift from gram-negative to gram-positive bacteria, with fewer Bacteroides and increased levels of Bifidobacteria. (19, 20) A similar shift has been observed in humans, even after a single dose of xylitol. (21) Additionally, the shifts observed allowed for more efficient use of the sugar alcohols by gut bacteria, which largely explains the reduction in GI symptoms after a few months of regular consumption.

In addition to the potential metabolic, dental, and prebiotic benefits already discussed, xylitol shows promise for preventing age-related decline in bone and skin health.

One interesting study found that 10% xylitol supplementation over 20 months increased collagen synthesis in the skin of aged rats, resulting in thicker skin. (22) Preliminary rat studies have also shown that xylitol can increase bone volume and mineral content and protect against bone loss. (23, 24, 25)

Overall, sugar alcohols appear to be safer than artificial sweeteners with several potentially therapeutic effects. Although the metabolic and weight loss benefits of sugar alcohols haven’t been studied as extensively, I would recommend sugar alcohols over artificial sweeteners to anyone who needs a low-calorie sweetener, although I wouldn’t recommend that anyone consume huge amounts of them. I’ll also be interested to see additional research on their ability to alter the gut microbiome and disrupt biofilms, because this could make sugar alcohols a useful tool for certain patients.

At this point, there don’t seem to be any major problems with sugar alcohols, so if it’s something you’re interested in, I would experiment with your own tolerance and see how they affect you. However, people with gut issues should be cautious.

What’s your take on sugar alcohols? Share your thoughts in the comments below!

189 Comments

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  1. So…

    I’ve seen these expensive Italian jams and marmalades that are made without any added sugars or sweeteners and then some diabetic ones made with sorbitol (Stute) which are much, much cheaper.

    Which should I buy?

  2. It is my personal opinion that Sorbitol is not suitable for food use. It may have drug uses such as a laxative…

  3. My family has been chewing xylitol gum for years and I am wondering if it stays in the liver indefinitely?

  4. I take Chris’s article to be cautiously optimistic re xylitol in humans and I am guessing he is maintaining a watching brief. I think this is a sensible approach, along with some caveats.

    Although xylitol has a low GI in humans and has minimal effect on blood glucose and insulin response in humans, its effects on these is variable in other animals, with the well-known response in dogs: ie marked increase insulin with potentially catastrophic outcomes

    It may well be that the response in rats is the same or similar to that in humans, but I read the results of experiments on xylitol in rats – and extrapolating the findings to humans – with a degree of caution – given the variability of effects of xylitol among mammals.

    In the end, the principle of eating food that is ‘natural’ for humans might be the best approach, but eating modest amounts of xylitol as opposed to large amounts of sucrose (or HFCS) in a refined diet is much the lesser of two evils.

    SL (veterinarian)

  5. My trouble is that I have been on erythitol (spelling) for years use it 5 times a day I used xylitol also but stop now I am off the stuff since over week and suffer severe constipation now. I wondering if this is why, while on sugar I went everyday normal stools. I know these sugars have a mild laxative effect, and now I cannot go unless I use senna which causes severe gas but does work. So much pain now.

    • Dee,
      Have you been able to figure this out yet? I hope you are not still taking senna every day to deal with the constipation – it is a very powerful herb and shouldn’t be used repeatedly for long periods of time, or you might mess up your gut flora and end up with a GI infection. Try eating lots of fiber to get things moving – greens, nuts, fruit with the skin. That will help regulate your bowels and give them something to work with.

      • Hi Dee and Rebekah,
        I am enrolled in a health coaching program which focuses on the endocrine systems (hormones). One supplement that we almost always include in our protocols is Buffered C. It’s mixed with potassium, calcium and magnesium. Straight C can be hard on the gut. I’ve been taking it for over 6 months now and prior to that had irregular bowel movements. I am now like clockwork on a daily basis. I typically take 1 gram (1 tsp) a day but if your bowels can handle it you can take up to 3 a day spread out AM, PM, evening.

        This being said, totally agree with Rebekah with ensuring you’re getting enough fiber from your foods.

        Hope this tidbit helps.
        Sandy

    • Dee – Fiber doesn’t help me. I’m a vegetarian so I naturally get lots of fiber, and it’s never helped with constipation. The only thing that’s ever worked for me is Earth’s Bounty oxy-cleanse. I took it for a month and it helped regulate me. I bought another bottle, but have yet to open it. The effects of the first bottle have lasted for more than two months now. I’ve had a normal bm every day since I stopped taking the pills.

  6. Today is the 20th of July 2016. I have been using Xylitol as a substitute to sugar for the past 3 years now. I only have 2 teaspoons per cup of coffee, yet I have had 3 – 4 cups in a day.
    Since day one I have suffered diarrhoea every single day, a few times a day but considering I normally have a sluggish bowel due to my IBS… I ignored this and took it as a good thing and just carried on…Now 3 years later I have chronic stomach cramps that come and go and on the advice on my gynae…I have stopped the xylitol but continue to have severe stomach cramps (yet the diarrhoea has gone)…Have I done longterm damage or will my stomach come right as I am now concerned.

    • Try slippery elm powder or acacia powder they are soluable fiber which is helpful for IBS. Can look up the info in health books and health food stores about Ibs they suggst never eat unsoluable fiber on an empty stomach

  7. Hi Chris, I randomly came across your site as I have just been able to get up from a vomiting migraine I’ve had since 7am. I was laying in bed this morning and thought the only unusual thing I did was eat a bunch of “natural” gum with Xylitol last night while I was reading. I never chew gum, eat processed foods or consume anything “diet” with artificial sweeteners. I am not perfect, I eat the piece of cake here and there, but at least it’s not processed. This migraine was very violent with regards to vomiting and other things… I’m pretty grossed out by my reaction to the alternative sweeteners in this gum. It was Pur Gum, perhaps it could be something else in the ingredient list. Hmmm.

    • It’s also not that great for humans. I’m surprised that Chris didn’t mention that xylitol increases oxalate levels, which can cause kidney stones and in some, muscle and joint pain.

  8. What about the manufacturing process to create these sugar alcohols? Hydrogenated foods, historically, have been horrendous for health.

  9. I can’t seem to tolerate any sugar alcohols / artificial sweeteners. They give me a three day migraine that is so painful. Sometimes I eat something without reading the label, the latest culprit a Quaker granola bar containing sorbitol. They are hiding in a lot of processed sweets.

    • I am extremely sensitive to sorbotol and have been accidentally exposed to it a couple of times. It’s the worst pain I’ve ever had and I’ve birthed six kids. Coming close was a twisted bowel episode I had a few years ago. Makes me wonder if the three sorbitol attacks I had had over the years contributed. Sugar alcohols are dangerous and should be banned. I can’t even chew sugar free gum anymore as the number One ingredient is sorbitol.

    • I just bought a charcoal toothpaste for tooth whitening. I used it 2 nights ago, and yesterday I had a day of horrible distress and pain and going going going. I blamed it on a small fruit tart I had eaten. Then I brushed with the toothpaste again last night, and today started off just as bad. Finally I looked at the itty bitty barely legible label of the toothpaste. First ingredient: SORBITOL! Then I looked at my Colgate toothpaste, which I found also had SORBITOL, tho not the first ingredient. This really explains a lot. If you’re sensitive to sugar alcohols, be sure to scrutinize labels.

  10. I’ve been using xylitol to sweeten my tea for several months now, thinking it was a safe sweetener. I’d put a heaping teaspoon in my tea, several times a day, and sometimes a heaping teaspoon on top of fresh fruit as an after-dinner dessert! I’ve been noticing weight gain that I can’t shake off, around my thighs and my stomach has a huge paunch. I have not reduced my physical activity and my diet is paleo, lots of veggies, fish, etc.

    Could it be the xylitol? It just dawned on me reading this: I remembered I tested allergic to birch – although I think that was birch pollen but not sure! Does that necessarily translate into an allergy to all things derived from birch trees?! When I realized this just now my eyes went 0.0 And my xylitol bag clearly states this brand is derived from birch!

    I’m gonna stop the xylitol immediately & see what happens.

    • Omg! When I started my new job – almost a year ago – I started chewing gum ALOT. I would chew “natural” xylitol gum all day long – everyday. Sometimes I would use the aspartame sugar-free ones as well (eek). I noticed I started becoming very ill…the same thing with the belly fat – like a HUGE belly and weight that I just couldn’t shake. I’d even say that I didn’t have time to eat before or during work, so my main nutrition during the day was xylitol gum, peppermints and aspartame gum (I work part-time). I went to get bloodwork done, and it turns out that I have elevated liver enzymes!!!! The doctor at the ER asked me if I drink a lot of alcohol, take a lot of pain meds or have hepatitis!!!! (No to all)
      I’m freaked out now wondering if this is all caused by the gum!! Really hoping damage is reversable!!!

  11. Xylitol almost removed my life-long constipation. Instead of taking loads of laxatives (as I used to, and it was seriously excessive, consisting of 4 pills of Senna, 1-2 pills Bysacodyl, 2-4 pills of Docusate Sodium DAILY) , I now just add a bit (1/2 teaspoon!) into my coffee in the morning and sprinkle some on the gluten-free waffle throughout the day and voila! Daily bowel movement without much straining (sorry for TMI). I surely hope the effect will not go away!
    Information for the curious – my diet is extremely healthy, plenty of veggies, a bit of fruit, trying to drink my 8 glasses of water a day, etc.,

    • I wish it would have that effect on me! See my comment above, but I have been using several heaping (!) teaspoons of xylitol daily in tea or on fruit and have never had this effect. I’ve been gaining weight though 0.0 I’ve always struggled with constipation myself but I use magnesium citrate for that – miracle worker!

    • What about fat…? At least 75% of your calories should be from fat sources, most of it saturated animal fat. You don’t need “loads of veggies”, humans are carnivorous omnivores, your focus should be on foods of animal origin, humans cannot efficiently assimilate nutrients from plants, and some vital nutrients, such as B12, cholesterol, folate (the folate in plants isn’t bioavailable to carnivores (and humans are more carnivore than omnivore), and herbivores synthesise B12, either by bacteria produced from rumen, or via coprophagy (the latter is true of Lagomorpha and also of many rodents), so we can only obtain it by eating animals (sorry veganists, it’s the truth whether you like it or not).

      Do you not see how contradictory your post is…? You claim your diet is “extremely healthy”, yet you need to OD on laxatives in order to have a BM – how can your diet POSSIBLY be healthy if that’s the case…?! First thing I’d do is eliminate grains completely, and swap that sugar-laden waffle (ALL carbs are converted to glucose once eaten), for a healthy high-fat snack, preferably meat-based (I like droewors, South African dried beef sausage). Contrary to what you’ve been brainwashed to believe, grains are NOT a staple food, they’re not food at all! You don’t need insoluble fibre to “bulk up your stools”, and that’s likely one cause of your constipation (or rather your inability to pass faeces unaided). I gave up grains nearly 20 years ago, and adhere to a low-carb/high-fat palaeo-as-far-as-possible diet. It has completely eliminated my IBS, due to the high fat content of my diet, I now have no trouble going at all.

      The other likely cause is your obsession with water. You DO NOT require “8 glasses a day” 8 is a completely arbitrary figure, without any basis in science, likely chosen because it’s around 2 litres, but NOBODY requires that much water in a day!

      The more you drink, the more you pee (obviously) and the more you pee, the more electrolytes you lose, potassium in particular, and potassium (K) is vital for smooth muscle to function and even mild, subclinical hypokalaemia can cause a reduction in peristalsis, leading to a build up of waste in the large intestine, colon and bowel. If your pee looks like water, it’s time to curtail your intake. Putting undue stress on the kidneys could eventually lead to complete renal failure, water IS NOT the benign substance many believe it to be.

      Drinking too much upsets the body’s delicately balanced electrolytes, leading to serious health problems and, if too much is consumed too quickly (the LD50 for a 9 stone 6lb (132lb/60kg) person is 5.4 litres consumed in a 6hr period) it can be FATAL!

      Drink when you’re thirsty but, if you find you’re unduly thirsty, get your K level checked.

      Finally, remember that around 90% of what your GP tells you is utter BS. Be sure to refuse statins if you’re offered them, interfering with the body’s own cholesterol management dramatically increases your risk of developing dementia/Alzheimer’s, diabetes, obesity, stroke, and, of course, heart disease. It can also lead to total hepatic failure. You have been warned!

      • 1. I used to take laxatives, do not take them any more.
        2. There is not “one diet fits all”
        3. I can not do saturated fat due to the chronic inflammatory state of my body – I have Multiple Sclerosis ( saturated fat promotes inflammation, which is fine for healthy people, because humans do need some inflammation – so called “controlled inflammation” )
        4. You say “you don’t need loads of veggies” – I do not force them into myself and enjoy them as a true omnivore
        5. I am completely gluten free and I have not been “brainwashed”.
        6. I do not do waffles, sugar or sweat drinks at all
        7. I know very well what carbs get converted to.
        8. I do not do Statins – where did that come from?

        Etc., etc., etc.,

        I have a Doctorate degree in Naturopathic Medicine and am pretty capable of analyzing my diet, my disease and my lifestyle.
        All in all I find your post rather offensive, assumptious and preachy.

        • In addition, constipation can be caused by an autonomic nervous system issue, something only an osteopath would be able to fix. I had severe tachycardia and POTS for years, probably caused by a bad fall on ice years ago, and caused me all sorts of nasty issues. If a malalignment problem can cause so many widespread and seemingly unrelated problems it stands to reason it could contribute to constipation, despite doing everything right diet-wise. My osteopath is fixing my POTS but it takes time, its a long journey, not something fixable overnight, but he has told me we will fix my digestion as well, as I have also had constipation for years despite a high vegetable intake.

        • #1. I have MS
          #2. Maybe I should say I had MS. Can MS be put into permanent remission like Type II diabetes through diet? I don’t know, I’m only speaking for myself.
          #3. I follow a Ketogenic lifestyle. I eat a lot of fat. Most of it is saturated fat, butter, cheese, bacon, bacon fat, chicken fat, chicken skin, animal fat, etc. Since consuming all of this saturated fat, it has improved my health dramatically in so many ways.
          #4. I have several other inflammatory conditions which have also resolved eating a diet high in saturated fat. If I had listened to all of the MS “experts” and avoided saturated fat, I’d probably still feel like one of the walking dead.
          #5. I follow two basic principles, eat when I’m hungry and drink when I’m thirsty. I don’t drink excessive volumes of water (like 8 cups per day), that would make me feel sick.
          #6. I think people could do more to become their own healers and leave the charlatans to do their voodoo dancing chanting under the moon alone where they belong.
          #7. I too switched from sugar to Xylitol, Stevia, Erythritol and Truvia (Stevia and Erythritol blend) and I’m convinced that along with the high sat fat diet have impacted my health for the positive. If these things are going to kill me down the road so be it, today I am living life like I have one again.
          #8. PS. I also avoid wearing sunscreen and soak up as much natural vitamin D as possible for the very same reason.
          #9. Great article Chris.

        • I actually liked all the comments because it shows what works for some and what works for others. I am sure your constipation is related to the MS….you all have very valid points.
          I do not agree that all saturated fats cause inflammation…some do but not all.
          The water comments are very interesting.
          I like when people comment even if they are insulting because we all can learn something from everyone

    • I read on WebMD that you can drink 4-6 glasses of water instead of 8. The exceptions would be if you live in a particularly warm climate and need to consume more or if you’re still thirsty after 4-6 glasses. However, there are some foods that are a water sources as well as juice(I stick with the unsweetened kind as well), coffee, tea and even fruits from what I understand.

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