Xylitol: Safe or harmful?

Xylitol is growing in popularity as a natural sugar substitute to sweeten various foods, gums, and oral care products. However, if you search the internet you find reports that xylitol is harmful and shouldn’t be consumed. So, what are the facts? Is xylitol a safe natural sweetener and sugar substitute with potential health benefits, or is it a toxic ingredient that should be avoided? Read on to discover the scientific facts of this often maligned sweetener.

What is xylitol?

This discussion needs to start with what xylitol is. Xylitol is a 5-carbon sugar alcohol (also called polyols) that has a crystalline, granular structure and sweetness comparable to sugar. Despite containing the name alcohol, xylitol contains no ethanol like alcoholic beverages. It is called a sugar alcohol like other sugar alcohols: sorbitol, mannitol, maltitol, isomalt, and lactitol  because its chemical structure places it in the alcohol family. It contains about 2.4 calories per gram (compared to 4 calories per gram for sugar). It is naturally found in some fruits and vegetables. Commercial xylitol is usually obtained from corn cobs or birch trees. Sugar alcohols are not processed the same as sugar absorbed and processed more slowly, which means that it provides fewer calories than the same amount of sugar and has less of an impact on blood sugar and insulin.

What is the problem or potential harm of xylitol and sugar alcohols?

Large amounts of sugar alcohols can cause gastrointestinal upset, such as gas, abdominal pain, and diarrhea.(1) However, the average person will not experience these effects unless they are consuming 50 grams or more per day. Indeed, research from the 1980s in the Soviet Union that administered 30 grams of xylitol per day observed that diarrhea and other side effects seldom occurred.(2) The same review of Soviet research concluded that xylitol is well-tolerated in children at doses of 20 to 35 grams daily for up to four weeks. People who are sensitive to sugar alcohols may experience GI symptoms — often severe — at much lower doses.

The most common report on blogs even among health professionals — is a concern about the toxicity of xylitol. This concern largely stems from animal research and appears to be misguided (more to come on this). It is important to remember that natural doesn’t always mean non-toxic. What determines toxicity is the dose of the substance (this principle is true of all substances regardless of whether it is natural or synthetic). A perfect example is water. Drinking too much water causes water intoxication (poisoning, seizures, and convulsions). Water is necessary to sustain life, but it can be toxic in excess. The same goes for many natural products, including xylitol.

What does research say?

Here is a brief summary of some of the research regarding toxicity in animals and humans.

  • Xylitol is extremely toxic to dogs (keep xylitol products away from man’s best friend) and can cause low blood sugar, seizures, liver failure, and death.(3)
  • Bladder tumors increased in mice when their diet consisted of 10% or 20% xylitol.(4) This is due to the conversion of a minor metabolite of xylitol called glycolic acid to oxalate. Increased oxalate in the urine predisposes mice to bladder stones, and in turn, bladder tumors. If humans consumed just 10% of their calories as xylitol, the average adult (based on a 2,000 calorie diet) would consume nearly 84 grams of xylitol daily. It would reach a whopping 167 grams if 20% of our calories came from xylitol.
  • At 20% of their diet, rats also experience an increased risk of tumor formation, but not at 10%.(4)
  • Humans do not readily convert glycolic acid to oxalate, and no increase in urinary oxalate levels has been observed even at doses of 1 g/kg body weight daily.(4) To put this in perspective, the average-sized person would need to consume 70 grams of xylitol daily to reach this level of consumption. Based on this no adverse effect, the study author concluded that humans exposed to normal levels of xylitol are at no risk of developing bladder tumors.

The current available research demonstrates that xylitol toxicity is species dependent, and not all animal studies can be directly correlated to humans. Current evidence in humans suggests it takes extreme amounts of xylitol to cause GI upset and potential harm.

Many products sweetened with xylitol (gum, breath mints, candy, protein powders) contain 1 gram or less of xylitol, meaning you would have to consume a significant amount of the products to even reach the safe level of 70 grams. Other products (jams/jellies — about 6 grams per tablespoon; baked goods) contain higher levels.

Benefits of xylitol

Research suggests that xylitol helps prevent tooth decay and cavities by preventing oral bacteria from sticking to teeth.(5) By preventing bacteria from sticking to teeth, xylitol reduces plaque formation. Remarkably, another review even found that xylitol can reverse the process of early cavities.(6) At least 5 grams of xylitol daily is necessary to produce a benefit to oral health, and some experts suggest 10 to 15 g in divided doses daily.(1) In addition, xylitol is a good choice for diabetics because it is low-glycemic and does not raise blood glucose or insulin levels like sugar.

Evidence-based conclusion

Based on the research and benefits of xylitol, it can be safely used in most adults at reasonable amounts (no more than 50 grams daily, but preferably less than 35 grams daily) and most children (less than 25 grams daily). Larger amounts may cause GI upset, while even small amounts may be problematic for sensitive individuals. Xylitol is beneficial for oral health, diabetics, and as a natural sugar substitute in reasonable doses, but should be avoided in excessive amounts.


(1) Makinen KK. Gastrointestinal disturbances associated with the consumption of sugar alcohols with special consideration of xylitol: Scientific review and instructions for dentists and other health-care professionals. Int J Dent. 2016;2016:5697907.

(2) Nesterin MF. Xylitol. Experimental and clinical investigations conducted in the USSR (review). Z Ernahrungswiss. 1980 Jun;19(2):88-94.

(3) Cortinovis C, Caloni F. Household food items toxic to dogs and cats. Front Vet Sci. 2016;3:26.

(4) Roe FJ. Perspectives in carbohydrate toxicology with special reference to carcinogenicity. Swed Dent J. 1984;8(3):99-111.

(5) Janakiram C, Deepan Kumar CV, Joseph J. Xylitol in preventing dental caries: A systematic review and meta-analyses. J Nat Sci Biol Med. 2017 Jan-Jun;8(1):16-21.

(6) Nayak PA, Nayak UA, Khandelwal V. The effect of xylitol on dental caries and oral flora. Clin Cosmet Investig Dent.  2014 Nov 10;6:89-94.

Bloated portions bloat American’s waistlines

When was the last time you had a reasonably portioned meal at a restaurant? Food portions at restaurants these days seem to be intended to serve more than one. Some portion sizes have doubled and even tripled at American restaurants over the last 20 years leading to excess calorie consumption. And these distorted portion sizes are a significant contributor to the growing overweight and obesity epidemic in America.

According to the National, Heart, Lung, and Blood Institute Obesity Education Initiative, in just over 20 years the average size bagel has more than doubled in size and calories. Likewise, your average plate of spaghetti and meatballs doubled in size and calories, now providing a whopping 1,025 calories per serving. During that same time period, soda servings have increased from an average of 6.5 ounces and 85 calories to 20 ounces and 250 calories. Is it any wonder that American’s waistlines are expanding as these bloated portions become the expectation for your typical meal?

The U.S. National Institutes of Health estimates that today’s excessive portions could easily lead to the consumption of an additional 500,000 calories per year. Those excess calories are a significant contributor to the rapidly increasing number of Americans who are overweight or obese — currently estimated to be two-thirds of Americans.

Fortunately, with the TransformWise approach to sensible portions, you can combat this trend of oversized portions and waistlines.

Each person is biologically unique with different calorie requirements — a 90-pound woman does not need the same amount of calories as a 225-pound man. That is why the TransformWise sensible portion approach relies on your hands as guide to determine reasonable portions.

  • Vegetables and fruits should make up the bulk of your diet, with a sensible portion being the size of your entire hand.
  • Wholesome carbohydrates should fit into your cupped hand.
  • Fats, preferably healthy fats, should be about the size of your thumb
  • And lean protein sources that cover your open palm is a reasonable portion of protein.

In addition, TransformWise advocates five to six smaller, metabolically balanced meals per day. The growing body of research suggests that eating five to six smaller meals and snacks per day offers myriad benefits, including better blood sugar control, balanced hormone levels, improved appetite control and increased thermogenesis — when your body uses excess calories to produce heat rather than storing them as fat.

For a more information and a complete guide to revealing your ideal physique and managing your weight, read TransformWise: Your Complete Guide to a Wise Body Transformation.

Single cheat meal causes diminished cardiovascular function

Many people allow themselves a “cheat meal,” or unhealthy meal, as a reward for reaching their fitness or health goals. Or they, may eat better during the week and lapse in those healthy eating habits over the weekend. Maybe it’s a holiday or party that destroys your eating plan. In fact, many nutritionists regard an occasional cheat meal as a beneficial practice when attempting to lose weight. What could one meal hurt anyway, right?

Well according to a 2012 study that single junk meal — with a significant portion of calories from saturated fat — harms your cardiovascular function immediately following the meal.(1) Specifically, cheat meals, or typical meals of the Standard American Diet (SAD), adversely affect vascular endothelium (the inner lining of blood vessels) function. Conversely, meals that more closely resemble the Mediterranean diet — rich in mono- and polyunsaturated fatty acids (like omega-3s) — may produce positive effects on vascular endothelium function.

Vascular endothelial function is one of the most significant predictors of and precursors to atherosclerosis. Atherosclerosis is a common disorder characterized by the hardening, thickening or lossburger-1140824_1920 of elasticity of the arterial walls. It is caused by a buildup of fat, cholesterol and other substances that form plaque in the walls of the arteries. This buildup may eventually result in the blockage of the arteries, leading to a host of health problems including heart attack and stroke.

The lead author of the study, Dr. Anil Nigam, Director of Research and the Cardiovascular Prevention and Rehabilitation Centre (EPIC), and colleagues compared the effects of junk food meals to a typical Mediterranean meal. The Mediterranean diet has long been associated with a reduction in heart disease and atherosclerosis.

The study included 28 non-smoking men, who ate a Mediterranean meal (salmon, almonds, and vegetables cooked in olive oil) one week followed by a junk food meal (a sandwich with sausage, egg and cheese, and three hash browns) one week later. After each meal, the researchers measured endothelial function in response to the foods consumed.

Surprisingly, it took only one junk food meal for the researchers to observe a 24 percent decline in endothelial function among participants when compared to their baseline before meals. Participant’s endothelial function remained normal following the consumption of the Mediterranean meal. This is a remarkable finding and should provide a reason to pause before succumbing to that double cheeseburger and fries the next time you are tempted to cheat.

salmon-923964_1920The study authors also discovered that participants with higher blood triglyceride levels benefited more from the Mediterranean meal when compared to participants with low blood triglyceride levels. Their arteries responded better after eating the Mediterranean meal, which suggests that a single healthy meal may also provide dramatic benefits to the cardiovascular system.

What we learn from this research is that every meal matters and can contribute positively or negatively to our health. To discover more benefits of omega-3 fatty acids read pages 41-44 of The Doctor’s Guide to Surviving When Modern Medicine Fails. Eat better and feel better!

(1) Cantin J, Lacroix S, Tardif J, et al. Does the Adherence to a Mediterranean Diet Influence Baseline and Postprandial Endothelial Function? Canadian J Cardiology. 2012 Sep-Oct;28(5):S245.

Eat berries, elevate heart health

Blueberries and strawberries are the most common berry consumed in the United States and a delicious snack during the summer when they are ripe and in season. Beyond being a healthy treat, evidence suggests that berries are packed with nutrients (anthocyanins) that may decrease the risk of heart attack.

Berries are a concentrated source of naturally occurring compounds called dietary flavonoids, which exhibit antioxidant activity. These beneficial nutrients support cardiovascular health, encourage healthy immune function, and even help prevent cancer. Flavonoids are also found in other foods like citrus fruits, dark chocolate, grapes, and onions.

Both animal and human studies have shown that a specific type of flavonoid, called anthocyanins, provide cardioprotective benefits, such as reducing atherosclerosis, lowering blood pressure and decreasing arterial stiffness. A study by Harvard researchers adds to the cardiovascular benefits of berries, suggesting that eating berries may reduce the risk of heart attack in women.(1)

The Harvard School of Public Health and the University of East Anglia in the United Kingdom collaborated as part of a prospective study to evaluate the cardiovascular benefits of berries. The study included 93,600 women ages 25 to 42 from the Nurses’ Health Study II. Participants were monitored for 18 years, completing dietary questionnaires ever four years.

What the researchers found was that women who ate the most strawberries and blueberries — three or more servings per week — decreased their heart attack risk by 32 percent when compared to women who consumed berries once a month or less. Remarkably, this fact held true even when women who consumed fewer berries ate a diet rich in other fruits and vegetables.

These findings suggest that berries have benefits that exceed those offered by other fruits and vegetables and should be an integral party of your healthy diet. However, eating a well-balanced diet with wholesome carbohydrates, lean protein sources, healthy fats and a variety of fruits and vegetables will ensure you get the range of nutrients essential to good health.

One way to get a daily dose of berries, which is growing in popularity, is through bioactive beverages or nutrient infusions. Many products exist on the market that combine a variety of superfruits — which include berries — into a concentrated nutrient infusion providing a range of beneficial nutrients. Most supply ample nutrients by drinking only one to four ounces daily.

Other ways to incorporate these health-promoting berries into your diet is by adding them to yogurt or cereal, mixing them into your whole-grain muffin mix, as part of a fruit and vegetable smoothie (see the recipe in TranformWise), dipping them into dark chocolate (you get more flavonoids this way), or topping your green salad with them.

(1) Cassidy A, Mukamal KJ, Liu L, et al. High Anthocyanin Intake Is Associated With a Reduced Risk of Myocardial Infarction in Young and Middle-Aged Women. Circulation. 2013;127:188-96.

Beware these five harmful ingredients lurking in your “food”

Much of today’s “food” comes in a box, bag, or package meant to be heated in the microwave. Busy lives and much to do has lead food manufacturers to cater to convenience rather than nutrition. If the food is not packaged, many people turn to one of the limitless fast food joints waiting to saturate your tissues with sugar, unhealthy fats, and other harmful nutrients.

Let’s face it, it is increasingly difficult to eat a well-balanced and nutrient-dense meal these days. And portions…don’t get me started on portions. There is a lot of opportunity to be exposed to harmful ingredients in today’s on-the-go meals, so let’s talk about some of the worst ingredients lurking in our food. With some knowledge and a little extra effort, you can keep these five dangerous food additives out of your shopping cart, and more importantly out of your body.

High-fructose corn syrup (HFCS) – While all added sugars should be limited as much as possible, HFCS is a sugar to be particularly concerned about. HFCS is a sweetener created by processing corn sugar to increase the level of fructose to about 55 percent, leaving the rest as 45 percent glucose. And if you think you have a healthy alternative in agave, think again. Depending on how agave is processed it could contain up to 90 percent fructose, making it far worse than HFCS. HFCS is sweeter than regular sugar making it less costly to add to products but also increasing the sweetness of products so they are more addictive.

HFCS is rapidly absorbed into your bloodstream because there is no chemical bond between glucose and fructose, causing an equally rapid spike in blood sugar levels. Research suggests that your body doesn’t process HFCS like regular sugar (sucrose), which means it doesn’t shut off your appetite center. Without signals being sent from your appetite center that you have consumed calories you are more likely to overeat.  Your liver is responsible for converting HFCS to glucose, but when too much HFCS is consumed it gets stored as fat, contributing to obesity and fatty liver deposits. In addition, HFCS increases your triglyceride levels, LDL cholesterol levels, contributes to diabetes and metabolic syndrome, depresses your immune system and even accelerates the aging process.

Watch out for this dangerous ingredient commonly found in: soda/soft drinks, baked goods, candy, sauces, salad dressings, yogurt, cereals. In addition, it may be hiding under another name such as glucose-fructose syrup, maize syrup, glucose syrup, crystalline fructose, tapioca syrup, dahlia syrup, or isoglucose.

Monosodium glutamate (MSG) – MSG is a flavor enhancer added to thousands of foods commonly consumed every day. It is strongly associated with short-term reactions such as headache, flushing, numbness or burning in the face and neck area, heart palpitations, nausea, chest pain, difficulty breathing and weakness — termed MSG symptom complex. MSG overstimulates the glutamine receptors in the brain, which enhances salty and sweet flavors. Some reports suggest that this overexcitement of glutamate receptors can cause cell death or damage and eventually leads to declined cognitive function. MSG also increases triglyceride levels, LDL cholesterol levels, contributes to diabetes and metabolic syndrome, depresses your immune system and even accelerates the aging process.

It is commonly found in: Chinese food, canned vegetables, soups, processed meats, crackers, frozen dinners, chicken and beef broths, potato chips. It can also be found on labels under the following names: autolyzed yeast, calcium caseinate, gelatin, glutamate, glutamic acid, hydrolyzed protein, hydrolyzed vegetable protein,  monopotassium glutamate, sodium caseinate, textured protein, yeast extract, yeast food, yeast nutrient.

Trans fats – Trans fats are a man-made fat used to enhance the flavor of and extend the shelf life of many foods. Research suggests it is more harmful than saturated fat (because it increases bad cholesterol, while simultaneously decreasing good cholesterol) and it has been linked to learning and memory challenges. Trans fats increase LDL cholesterol and triglyceride levels while lowering HDL (good) cholesterol levels, which significantly increases the risk of heart disease, heart attack, and stroke. It is also associated with an increased risk of developing type II diabetes. Trans fats are commonly found in: fried foods, baked goods, potato chips, crackers, margarine, fast food, packaged foods, cookies, frozen foods, dips. It may be hiding on labels under these additional names: partially hydrogenated vegetable oil. Unfortunately, manufacturers are allowed to call their product fat free as long as the trans-fat content is 0.5 g or lower, so you need to read labels carefully.

Sodium nitrite – A salty preservative and color corrector used in some meats, sodium nitrite has been linked to certain cancers and heart disease. Some experts credit this nasty additive as the reason processed meats are so strongly associated with cancer. Research suggests that those who eat the most processed meat (known to contain sodium nitrite) have a greater risk of cancer and heart disease than people who eat red meat. During digestion, sodium nitrite combines with amino acids to form nitrosamines, which are very harmful to the liver and pancreas and highly carcinogenic. They are commonly found in: processed meats, hot dogs, sausage, bacon, beef jerky, deli meats, and canned soups. It may also be listed on a food label as nitrate, nitrate, or sodium nitrate.

Artificial sweeteners – Artificial sweeteners are used in a variety of products to decrease caloric intake and to provide a sweetener that diabetics can use without significantly affecting blood sugar levels. However, evidence suggests that diet soda drinkers (sweetened with artificial sweeteners) are more likely to become overweight, obese and have a larger waistline than those who drink full sugar soft drinks. This is because some artificial sweeteners pass through the digestive tract largely unmetabolized. Beyond obesity, artificial sweeteners are associated with an increased risk of heart disease, diabetes, metabolic syndrome and kidney disorders. Some reports indicate that artificial sweeteners may cause gastrointestinal problems, allergic reactions, migraines, cancer, and kidney, liver and thyroid damage. Artificial sweeteners are in many low-fat and sugar free foods including: Soft drinks/soda, sugar-free gum, candy, yogurt, diet foods, snack bars, and cereal. Artificial sweeteners are called many names, such as: acesulfame potassium, acesulfame-K, aspartame, neotame, saccharin, and sucralose. A much better low-calorie sweetener option is stevia.

To learn more about the research behind these harmful ingredients, see pages 53-54 of The Doctor’s Guide to Surviving When Modern Medicine Fails. Do your family and personal health a favor and keep these nasty ingredients out of your grocery cart. Your body will thank you.