Do Artificial Sweeteners Cause Diabetes, Cancer and Weight Gain?

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 be and be 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). So, 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 five 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 result in a negligible amount of calories (3). Aspartame is the most controversial artificial sweetener, and a recent study using rats 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, the 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 glucose 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, and 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 the intake of glucose, but the 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 (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 the risk of diabetes?

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

One study found that the association between artificially sweetened beverages and the 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 the risk of diabetes (this does not mean it will never be explained if it is true).

A study had subjects sucking on sucrose, an unsweetened polydextrose (a fiber) tablet, or an 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 the 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 sweetener 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 it differently 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 studies 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 they do 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 of 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 that 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 the intake of artificial sweeteners and weight gain (10).

The intense sweetness of these artificial sugars may cause hyperstimulation 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 being 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 a 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 (the desire to eat pleasurable food in the absence of an energy deficit), which is known to increase appetite and thus weight gain.

Reward system for sweet foods

Studies have shown that humans’s appetites are actually increased by sweet foods, whether by sugar or artificial sweeteners. Many pleasurable activities, such as 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 postpartum 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 an effect artificial sweeteners can have on our brains, 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 changes, vomiting, and diarrhea (8). Long-term consequences may include an 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 be 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 300 times sweeter than sugar). Many beverages now use stevia, including vitamin water and soda 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 drunk 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 be 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 one’s appetite for sweet foods and causing weight gain, which will increase the risk of developing 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 who consume 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, lead to weight gain, and may cause cancer and tumors. The less we ingest, the better.

 Sources

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 JOURNAL, 56(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 safety, 5(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 Nutrition, 105(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 nutrition, 93(6), 1321-1327.
7. Abdallah, L., Chabert, M., & Louis-Sylvestre, J. (1997). Cephalic phase responses to sweet taste. The American journal of clinical nutrition, 65(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 oncology, 18(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 Obesity, 5(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 medicine, 83(2), 101.
12. Lenoir, M., Serre, F., Cantin, L., & Ahmed, S. H. (2007). Intense sweetness surpasses cocaine reward. PloS one, 2(8), e698.