Do artificial sweeteners cause diabetes, cancer and weight gain?


chocolates-270022_1280 (2)The first artificial sweetener was discovered over 100 years ago. It was first marketed as a sugar alternative for those with diabetes. Later, companies likely saw the potential for huge profits and started marketing these sweeteners as “calorie free” alternatives to sugar to aid in weight loss and suitable for all.

It is pretty much accepted that refined sugar intake is linked to the onset of obesity and diabetes. Refined sugar is not filling and consumption of soda with high levels of sugar has been shown to induce significant weight gain. Because of these reasons many people turn to artificial sweeteners.

Per person intake of diet drinks has increased from less than 1 oz per day in the 1960s to about 4 oz per day during this decade (1). Soooo we know that sugar is bad but are artificial sweeteners really a healthy alternative to sugar? Do they cause weight gain, diabetes and cancer? The verdict is not quite out yet but there are plenty of interesting studies to talk about.

The five approved artificial sweeteners

There are currently 5 artificial sweeteners approved by the FDA:  sucralose (Splenda), saccharin (sweet N low), aspartame (Nutrasweet), neotame and acesulfame. These artificial sweeteners are anywhere from hundreds to thousands of times more potent than sugar.  Saccharin (sweet N low) and acesulfame-K are not absorbed or metabolized by our bodies (2). They pass through our body unchanged and are excreted by the kidneys (2). Sucralose passes through the body unchanged and is excreted in our feces (2). Neotame passes through the body unchanged and within 72 hours is completely eliminated from the body in urine and feces (2).

Aspartame is metabolized by the human body just like other sugars and contains the same amount of calories per gram as sugar but it is intensely sweet so the small amounts used results in a negligible amount of calories (3). Asparatame is the most controversial artificial sweeteners and a recent study using rats have linked it to malignant tumors in males, an increase in lymphomas and leukemia in males and females, and an increase in mammary cancer in females (3). A very important note is that this study used a dosage of aspartame similar to that which is considered safe for human use.

 Can our gut tell the difference between sugar and artificial sweeteners?

There is a theory that our gut, like our tongue, is unable to tell the difference between real sugar and artificial sweeteners and that sugar receptors in our gut respond to both of them equally. (4). Studies have shown that oral intake of glucose causes a greater insulin response than an IV injection of glucose, hinting that the intestinal lumen may have receptors for glucose (4). If true, intake of artificial sweeteners would cause the release of gut hormones.

A study showed that our gut does not react the same way to artificial sweeteners as it does with real sugar (4). Subjects were given glucose, fructose or an artificial sweetener and their GLP-1 and fasting plasma grhelin were measured (4).  Glucose increased the plasma GLP-1 (stimulates insulin production-happens when sugar is ingested) while there was no increase in plasma GLP-1 after intake of the artificial sweeteners (sucralose, aspartame, acesulfame K) or in plain water (4).

After glucose intake fasting plasma ghrelin levels were reduced  (showing reduced hunger)  while the artificial sweeteners and water had no effect-showing that the artificial sweeteners did not increase nor decrease hunger and were likely not metabolized by the body (4). Glucose raised blood glucose levels while the artificial sweeteners and water had no effect (4). Plasma insulin levels rose after intake of glucose but intake of artificial sweeteners had no effect on insulin levels (4).

In a study where subjects drank diet soda or carbonated water researchers found that there were no significant differences in plasma glucose or insulin after intake of diet soda versus carbonated water intake (5). Chemically, artificial sweeteners and sugar are similar, but there are a few foundational differences in their chemical makeup which likely results in our body not treating artificial sweeteners in the same manner it treats sugar.

Do artificial sweeteners increase risk of diabetes?

Some studies have found an association between intake of artificial sweetened foods/beverages and increased risk of diabetes. This relationship is hard to verify for a few reasons. A large proportion of people that drink artificially sweetened beverages may have switched because they were diagnosed with diabetes and had to cut out sugar. People that drink artificially sweetened beverages may have poorer diets compared to people that drink only water and tea.

One study found that the association between artificially sweetened beverages and risk of type 2 diabetes was explained by the health status, body mass index, pre enrollment weight change and dieting of those involved in the study (6). Also of importance is the fact that scientists cannot explain why artificially sweetened beverages would increase risk of diabetes (this does not mean it will never be explained if it is true).

A study had subjects suck on a sucrose, an unsweetened polydextrose (a fiber) tablet, or aspartame polydextrose (a fiber) tablet (7). Their insulin and glucose levels were continuously monitored. The study found that only sucrose but not the polydextrose tablet or aspartame tablet raised insulin and glucose levels. A different study spanning three months had subjects with type 2 diabetes take a large amount of a sucralose capsule every day. The researchers found that there was no difference in the fasting plasma glucose of the sucralose group compared to the control group (taking a harmless daily cellulose cap) and that taking sucralose daily had no effect on glucose homeostasis (8).

These studies showed that artificial sweeteners do not raise glucose or insulin levels like real sugar does and thus likely do not cause diabetes.

Do artificial sweeteners increase risk of cancer?

Most of the research linking artificial sweeteners to increased cancer risk came from rodent studies in the 1970s which found an increased bladder cancer risk associated with extremely high levels of saccharin intake along with a few studies on humans (9). More current research has failed to find an association between artificial sweeteners intake and cancer risk. In fact, it was later found out that the breakdown of saccharin in the body was species specific meaning that rodents metabolized this different than human beings (9).

A study from Italy found an association between artificial sweetener intake and laryngeal cancer risk but failed to find an association between artificial sweetener intake and other types of cancer (9). Overall, there are mixed findings. Many studies found no association while fewer amounts found an association between artificial sweetener intake and cancer risk.

Just because the majority of studies found no harm from artificial sweeteners does not mean that it does not cause cancer. This would require well controlled and long studies spanning decades which are incredibly hard to complete. Short term and animal studies do not tell us the long term negative effects from ingesting artificial sweeteners over one’s lifetime. Adding to this is the fact that companies that discovered the artificial sweeteners funded some of the studies which found no harm from their sweeteners.

Do artificial sweeteners cause weight gain?

It is very possible and supported by research that people who switch to soda or foods with reduced calories from artificial sweeteners may believe they saved calories and actually end up eating more calories by the end of the day. This is especially true if these low calorie foods are added to the diet instead of substituted for something like regular calorie soda (1). Observational studies in children have largely shown a link between intake of artificial sweeteners and weight gain (10).

The intense sweetness of these artificial sugars may cause hyper stimulation of the sugar receptors on our tongue and change our taste receptors as we become accustomed to this intensely sweet substance. This can result in fruit tasting less sweet and therefore less appetizing and unsweet foods like vegetables less enjoyable while increasing our desire for intensely sweet food. This may cause an increased consumption of refined sugar in very sweet foods like cakes, candy and chocolate.

Animals (including humans) have evolved to seek food because we have certain cravings (like for sweetness) even in the absence of need for calories or hunger. This refers to the hedonic components of food (eating food for pleasure and not need). The artificial sweeteners may be able to activate the hedonic component (desire to eat pleasurable food in the absence of an energy deficit) which is known to increase appetite and thus weight gain

Reward system from sweet foods

Studies have shown that human’s appetites are actually increased by sweet foods- whether by sugar or artificial sweeteners. Many pleasurable activities such as a good tasting food, sex, and drug use all share common brain pathways (11). The two branches of food reward are sensory and post ingestion (11). Sensory refers to the taste we perceive on our tongue which sends a signal to the brain. Post ingestion refers to the metabolic products resulting from the breakdown of ingested food.

Studies support the idea that artificial sweeteners do not activate the food reward system as real sugar does. This may be because the lack of calories eliminates the postingestive component (11). Sugar has been shown to activate different sensory areas for taste than artificial sweeteners (11). Because of these facts scientists hypothesize that being devoid of calories the intense sweetness of artificial sweeteners only activates a part of the food reward system (11).

So, this is a good thing right? Not necessarily. It is thought that artificial sweeteners activate the sensory reward system but leave the post ingestion component desiring to be satisfied with actual sugar or calories. This may cause a desire for real sugar causing people to eat sugary foods to satisfy the post ingestion component.

Cocaine or saccharin?

To illustrate just how powerful of an effect artificial sweeteners can have on our brain look at the following study (I do not usually include animal studies for reasons I will explain later but I found this one to be very interesting). A study involving rodents let them pick between two levers- one that dispensed an oral saccharin solution and another that dispensed cocaine (12). Somewhat surprisingly, the researchers found that most of the animals (94%) picked the lever dispensing the saccharin solution over the lever dispensing the cocaine (same source).

Products that contain artificial sweeteners

A lot of the different types of artificial sweeteners are mixed together in products such as cakes, pies, soft drinks, chewing gum, frosting, frozen desserts, jams, jellies, pudding, processed fruits, etc. (8). Artificial sweeteners are in more than 6,000 products which include foods, medications and even cosmetics (8). If in doubt check the label!

Side effects from artificial sweetener intake

Reported side effects from various artificial sweeteners are: headaches, dry mouth, dizziness, mood change, vomiting, and diarrhea (8). Long term consequences may include: increased risk of bladder cancer, lymphomas (tumors of certain tissues), brain cancer and thymus shrinkage (8). Remember that artificial sweeteners literally pass through the body unchanged which can cause diarrhea. Sometimes when the artificial sweeteners are broken down in the body they release toxic substances (most likely not in high enough amounts to pose a problem).

Resetting our taste buds

Numerous studies have shown that we get used to and like the foods we typically eat. This means that if we are used to eating foods with high amounts of salt or sugar then we learn to prefer foods that have high levels of both. Foods lacking these chemicals will be less enjoyable and have less flavor. This will lead us to search for foods that are high in salt or sugar. Having the daily stimulus of artificial sweeteners in foods or beverages will cause our taste buds to get used to extremely sweet food and lead to a preference for sweet food. The only way to change the amount of sweetness we are used to is to allow our taste buds to reset. This would mean greatly or completely eliminating sweet foods (whether from sugar or artificial sweeteners).

Our taste buds are replaced about every 10 days. I had a hard time finding out if this is how long our taste buds take to “reset” from high levels of salt and sugar (if you can find out please let me know!). If you do not believe that our taste buds can reset try for yourself. Cut out all added sugar for 2 weeks. Go back and eat a brownie or cake. I can guarantee that it will be too sweet! Once your taste buds become accustomed to less sweet foods highly sweet foods will start to taste too sweet and less sweet foods and fruits will have the perfect amount of sweetness. Fruit is nature’s candy that we have evolved to eat and artificially sweet foods can ruin our appetite for less sweet foods.

A natural alternative to sugar and artificial sweeteners- Stevia

 I have been taking stevia for many years, back when it was only sold as a supplement in health food stores. Stevia is a natural sugar from a plant- similar to sugar coming from sugar cane plants. Stevia is extremely sweet (up to 300X sweeter than sugar). Many beverages now use stevia including vitamin water and sobe life water. Because such small amounts are needed stevia is essentially calorie free. I often use it in lemonade and coffee.

I must tell you that stevia does not taste exactly like sugar. It has a unique taste that some people like and some people do not. I am not advocating using stevia all of the time. Because of its sweetness it still causes other foods to taste less sweet and less desirable. All I am advocating is using stevia in place of sugar and artificial sweeteners. It is probably best if you limit its use so your taste buds do not become accustomed to very sweet tastes.

Personal Opinion

 If someone asked me whether or not I would recommend drinking diet soda I would say only if they would have drank regular soda otherwise. Just because artificial sweeteners are likely less harmful than sugar does not mean they should be consumed. A lesser of two evils is still bad. I believe that artificial sweeteners are so sweet that they cause other less sweet foods to become less desirable.

This is very hard for many people but I believe if someone wants to lose weight or cut out sweets they should abstain from ALL artificially or naturally sweetened foods. Give your taste buds a chance to reset. Once you become desensitized to extremely sweet foods you can still drink diet soda here and there but I would not recommend drinking it every day. We should always air on the side of caution. Even if it is unlikely that artificial sweeteners cause cancer, why take the risk however small it may be? There are already an overwhelming amount of things we do each day that increase cancer risk so why add one more?

I do not believe that artificial sweeteners directly cause diabetes. I believe they may indirectly cause diabetes by increasing ones appetite for sweet foods and causing weight gain which will increase the risk for diabetes. I have already discussed how artificial sweeteners can increase appetite and weight gain. Another problem is people believing they saved calories by switching from soda to diet soda and believing they can eat more calories and end up consuming more calories than they would if they had not drank the diet soda.

Because artificial sweeteners are created in the lab we cannot look at populations that have been habitually consuming artificial sweeteners as part of their diet for centuries. In a way, we are guinea pigs for artificial sweetener use and disease risk. We are people in the real world consuming high amounts of artificial sweeteners daily. We may one day find out any long term side effects from artificial sugar use but separating artificial sugar use from other bad foods is nearly impossible especially in the real world.

Final say– I believe that artificial sweeteners do not cause diabetes but they do increase our appetite and lead to weight gain and may cause cancer and tumors. The less we ingest the better.


  1. Mattes, R. D., & Popkin, B. M. (2009). Nonnutritive sweetener consumption in humans: effects on appetite and food intake and their putative mechanisms.The American journal of clinical nutrition,89(1), 1-14.
  2. Whitehouse, C. R., Boullata, J., & McCauley, L. A. (2008). The potential toxicity of artificial sweeteners.AAOHN JOURNAL56(6), 251.
  3. Kroger, M., Meister, K., & Kava, R. (2006). Low‐calorie Sweeteners and Other Sugar Substitutes: A Review of the Safety Issues.Comprehensive reviews in food science and food safety5(2), 35-47.
  4. Steinert, R. E., Frey, F., Töpfer, A., Drewe, J., & Beglinger, C. (2011). Effects of carbohydrate sugars and artificial sweeteners on appetite and the secretion of gastrointestinal satiety peptides.British Journal of Nutrition105(09), 1320-1328.
  5. Brown, R. J., Walter, M., & Rother, K. I. (2009). Ingestion of diet soda before a glucose load augments glucagon-like peptide-1 secretion.Diabetes Care,32(12), 2184-2186.
  6. De Koning, L., Malik, V. S., Rimm, E. B., Willett, W. C., & Hu, F. B. (2011). Sugar-sweetened and artificially sweetened beverage consumption and risk of type 2 diabetes in men.The American journal of clinical nutrition93(6), 1321-1327.
  7. Abdallah, L., Chabert, M., & Louis-Sylvestre, J. (1997). Cephalic phase responses to sweet taste.The American journal of clinical nutrition65(3), 737-743.
  8. Grotz, V. L., Henry, R. R., McGill, J. B., Prince, M. J., Shamoon, H., Trout, J. R., & Pi-Sunyer, F. X. (2003). Lack of effect of sucralose on glucose homeostasis in subjects with type 2 diabetes.Journal of the American Dietetic Association,103(12), 1607-1612.
  9. Gallus, S., Scotti, L., Negri, E., Talamini, R., Franceschi, S., Montella, M., … & La Vecchia, C. (2007). Artificial sweeteners and cancer risk in a network of case–control studies.Annals of oncology18(1), 40-44.
  10. Brown, R. J., BANATE, M. A., & Rother, K. I. (2010). Artificial sweeteners: a systematic review of metabolic effects in youth.International Journal of Pediatric Obesity5(4), 305-312.
  11. Yang, Q. (2010). Gain weight by “going diet?” Artificial sweeteners and the neurobiology of sugar cravings: Neuroscience 2010.The Yale journal of biology and medicine83(2), 101.
  12. Lenoir, M., Serre, F., Cantin, L., & Ahmed, S. H. (2007). Intense sweetness surpasses cocaine reward.PloS one2(8), e698.


13 thoughts on “Do artificial sweeteners cause diabetes, cancer and weight gain?

  1. rita henkle

    Tengo una pregunta referente a las aguas gaseosas de dieta
    estas seran tan malas como las normales. y es preferiblemente tomarse una de coca diet
    me encanto este tema de los endulzantes asi que espero respuesta para que tengta claro
    este tema

    1. RobertRobert Post author

      El azucar es peor que los endulzantes artificial. Si tu tienes que tomar uno tomaria coca diet pero tu no necesitas tomar cualquiera de los dos. Pero toma coca diet a veces esta bien!

  2. Bernal Herrera

    I once read (I don’t know if it’s true…) that a 8 year old kid in our times has consumed more sugar than an adult in his whole life 100 years ago !!

    Very interesting….nice lectures you deliver us every week !

    1. RobertRobert Post author

      Hi Bernal. You know what, I actually do not know how much added sugar people consumed in the early 1900’s. I would definitely be interested in finding out. I will look into and get back to you!

      Thanks for the question!

  3. Lucia Henkle

    This is a very interesting topic. You hear that it is better to use artificial sweeteners than sugar and in the other hand, you hear that artificial sweeteners are sometimes even more dangerous than the actual sugar. So you really don’t know which one is true or which one to follow. This articles made me understand this topic better. I am really enjoying reading your articles. 
    I have a history of diabetes in my family so this topic is important for me.

    Personal fact: Regarding Stevia, this is the artificial sweetener I use at home; this leaves an after taste I don’t like much and sometimes I rather use real sugar. (sometimes nothing beats the original taste).

    I found Bernal’s comment about the 8 year old kid very interesting. I do believe is true!

    1. RobertRobert Post author

      Hey Lucia. I agree that real sugar does taste slightly better than stevia but I cannot bring myself to add sugar to anything I drink or eat. It is either stevia or nothing for me. But adding a little sugar once in a while most likely will not result in long term harm. A lot of people hear “artificial” and have a knee jerk reaction that it is bad for you because it is not “natural.” Just because something is natural (example- tobacco, sugar, cocaine) does not mean it is good for you. And just because something is artificial does not mean it is bad for you.

      The real danger of artificially created foods is lack of long term health studies. I was searching Youtube to find a good unbiased report on the dangers of artificial sweeteners and unfortunately was met with a lot of videos overexaggerating the dangers and emphasizing only a few studies supporting their view. I do not believe in scaring people with overexaggarations and conveniently leaving out data that goes against my view like so many people do. I really intend this blog for educating people on various health topics and allowing them to form their own opinion.

      Thank you for your input like always!

  4. Diabetes cure

    I’ve been type 1 since 1970 and my initial diabetic diet was relatively low-carb — at least compared with what in the Eighties was conventional wisdom. I spent decades eating cereal with skimmed milk and pasta with marinara sauce and being told by board-certified endocrinologists that I just needed more exercise and more insulin to get my hemoglobin A1c under 10.5 or so. The culmination was Symlin, an expensive synthetic relative of amylin that left me nauseated every waking moment but helped a little, partly by slowing digestion and partly by making me too nauseated to eat much. About five years ago I went low-carb and when I belatedly saw my endocrinologist he was pleased that my A1c was around 8 but insisted that the human brain cannot function on under 100g of dietary carbs a day. Now my A1c runs around 6.5 and I’m still overweight but my complications are getting no worse. My hatred for the American Diabetes Association is boundless.

    1. RobertRobert Post author

      Hi! I do not agree with low carb diets even for people with diabetes. Fruit can actually be helpful for those with diabetes. Refined sugar is terrible though. Your doctor was right about our brain needing carbs (glucose). Your body can make glucose from amino acids (which make up proteins) and glycerol from fats. This only occurs when we fast or have inadequate carb intake. It is much easier and probably safer for our body to use glucose from carbs and not to convert amino acids or glycerol. I have looked into very low carb diets before to see the effects it has on health but unfortunately there are few to none long term studies of people consuming extremely low carb diets. Maybe because it is not practical or safe. I am not really sure though

      What does Symlin do? And why do you not like the Diabetes Association? I mostly dislike the fact that they have sponsors which are food companies. This limits the amount of free speech the association has. Looking forward to hearing from you.


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