Dangers of Artificial Sweeteners

Artificial sweeteners have long been heralded as “healthy” alternatives to sugar. Millions of calorie-conscious consumers sprinkle pale pink, yellow, or blue packets in their coffee each day. While millions more unknowingly consume concoctions of the chemicals in sweetened foods. But just how safe are these chemicals? And are there any artificial sweetener side effects you need to know about? 

What Are Artificial Sweeteners and Why Are They Used?  

Artificial sweeteners are sugar substitutes commonly used to sweeten foods without adding additional calories. As artificial sweeteners are many times sweeter than sugar only a minuscule amount, with negligible calories, is required to achieve the same flavor.

The Food and Drug Administration (FDA) has approved six artificial sweeteners for use as food additives in the United States and regulates their use in foods and beverages, such as sodas, salad dressings, granolas, and yogurts. 

  • Acesulfame potassium (marketed as Sunett and Sweet One)
  • Aspartame  (marketed as Equal, NutraSweet and Sugar Twin)
  • Advantame (no brand name)
  • Saccharin (marketed as Sweet ‘N Low, Sweet Twin, and Necta Sweet)
  • Sucralose (marketed as Splenda and Canderel)
  • Neotame (marketed as Newtame)[1]

How Were We Falsely Led to Believe Artificial Sweeteners Were Good For Us? (“No sugar!” “Enhanced weight loss!”)

Saccharin blazed the trail for all other artificial sweeteners. Constantin Fahlberg, a chemistry professor at Johns Hopkins University, discovered it by accident in 1879. The story goes that he noticed an intensely sweet taste on his hands after a day of researching coal tar derivatives. He raced back to the laboratory to sample everything in sight (breaking the most simple of lab safety protocols) and eventually connected the sweet taste with a chemical compound known as benzoic sulfimide.[2]

Fahlberg was quick to recognize the potential of this sweet-tasting chemical, which wasn’t metabolized in the body, and quickly applied for patents.

Saccharin hit the shelves as a medicinal product safe for diabetics and remained so until sugar shortages during World War I and II lead to widespread consumption. Once economics recovered and sugar became affordable again, saccharin needed a new angle. Instead of marketing saccharin as a low-cost alternative to sugar, it was advertised as a miracle no-calorie sweetener.  

A profitable market for diet products ensued, with manufacturers targeting females with (hilariously) aggressive advertisements. Kirsch, the creator of No-Cal Ginger Ale, used a cunning cartoon of a young lady unable to get her button up alongside the caption “Time to switch to No-Cal: absolutely non-fattening.” 

While saccharin was proving to be an extraordinary success, consumers were complaining of an unpleasant, metallic aftertaste. Fortunately for the artificial sweetener industry, the FDA had just approved a new chemical in 1958. A chemistry student at the University of Illinois discovered the compound, known as cyclamate when he noticed a sweet taste on his contaminated cigarette.

Cyclamate had a more pleasurable taste that could mask the bitterness of its predecessor and became the hugely successful tabletop sweetener “Sweet N’ Low.” The discovery of further artificial sweeteners in the second half of the 20th century, in combination with rising levels of obesity, fueled the diet industry. Today products labeled with “No Sugar!” and “Enhanced Weight Loss” fly off the shelves without a second thought.

But has the FDA declared artificial sweeteners as safe without really knowing the long-term consequences? The answer is likely, yes. 

Research Unveils Scary Artificial Sweetener Side Effects

A debate over the safety of artificial sweeteners has existed since the 1970s. Here’s the low-down:

Artificial Sweeteners & Cancer: An Ongoing Saga

Widespread concern was sparked in 1969 when the FDA banned cyclamate (Sweet N’ Low) from all food in the USA in response to studies that showed cyclamate-induced bladder cancer in laboratory rats. [3,4] The FDA’s decision was further supported by evidence in humans and after this, Cumberland Packing Corporation quickly swapped Sweet N’ Low to a saccharin-only product.[5] 

Over the following years, further scientific studies linked saccharin to the development of tumors in rodents, prompting the FDA to announce its intention to ban saccharin too.[6,7] Congress took a milder approach, and instead of a complete ban, imposed a law that all saccharin-containing products be labeled with the warning that saccharin can cause cancer in laboratory animals.

However, follow-up studies later demonstrated that the mechanism is not possible in humans and that the development of cancer in rats was due to a specific feature of their digestive system.[8,9] Cyclamate remained banned, but the warning label on saccharin was removed in 2000. It appeared the artificial sweetener industry had won the battle until 2005 when a study found that rats given high doses of aspartame were more likely to develop lymphoma and leukemia than those given sugar.[10]

Aspartame was introduced in the United States in the 1980s under the names Equal and NutraSweet. It’s one of the most common no-calorie artificial sweeteners and is currently found in over 6,000 products. 

The study was criticized as the rats were fed the equivalent of up to 2,083 cans of diet soft drink each day. In response to criticism, the same researchers conducted a follow-up study, in which male and female Sprague-Dawley rats were exposed to very low doses of aspartame in their feed (20 or 100 mg/kg of body weight) from fetal life until natural death. The results confirmed that aspartame is a carcinogen, even at doses that fall within Acceptable Daily Intake (ADI), which is set at 50 mg/kg of body weight in the United States. The study found a significant dose-related increase in the rate of lymphomas, leukemias, and mammary tumors.[11]

The study also reported that prenatal exposure to aspartame increases the incidence of leukemia in females. Unlike most other artificial sweeteners, which pass through the human body without being digested, aspartame is broken down and absorbed as three different compounds: aspartic acid, phenylalanine (which are amino acids) and methanol. Of these compounds, methanol is the most concerning. Under long-term exposure, methanol can convert into formaldehyde, a known carcinogen that has been shown to interfere with DNA replication. 

The American Cancer Society points out that a 12-ounce can of diet coke contains 192 mg of aspartame. This means the average American adult weighing 75 kilograms would need to consume 8 cans of diet coke to meet the equivalent of 20 mg/kg (the quantity that induced cancer in rats). However, this also means an average 10-year-old child, who weighs 32 kilograms, only needs to drink the equivalent of three cans of diet coke daily. If a child is regularly consuming a range of artificially sweetened foods, beverages, and medications, reaching this limit doesn’t seem impossible.

Despite these alarming findings, the National Cancer Institute currently states there is no clear evidence to demonstrate artificial sweetener increases the risk of cancer in humans. According to the council, epidemiological studies performed in humans have failed to support the link between sweeteners and the development of cancer. However, a 2015 review involving 599,741 participants concluded that heavy consumption might increase the risk of certain cancers (laryngeal, urinary tract, leukemia and non-Hodgkin’s lymphoma.[12] Personally, it’s enough to make me check every single label before putting it in my pantry! I would encourage you to do the same.

Hinder Attempts to Lose Weight 

Artificial sweeteners are intended to help manage weight. However, recent literature reviews suggest the direct opposite is true.[13,14] In fact, artificial sweeteners might actually promote weight gain and increase appetite. The well-known San Antonio Heart Study assessed the diets of 3,682 adults between 1979 and 1988 and found that participants who consumed artificial sweeteners had a 47% higher BMI after cleaning the data for conflicting factors, like diabetes, regular exercise, and dieting.[15] Furthermore, a 1986 study by the American Cancer Society involving 78,694 women found that those who consumed artificial sweeteners were 7.1% more likely to have gained weight.[16]

How could this be?

Deactivates Food Reward Pathway

Consuming artificial sweeteners to curb your cravings could inadvertently leave you yearning for more by disabling the body’s regular food reward pathway. When natural sugar enters the body, it stimulates our sweet taste receptors, which not only tell the digestive system it’s time to absorb nutrients but also send signals to the brain about satiety.

Two important messengers are involved in this process of appetite suppression: Glucagon-like peptide (GLP-1) and peptide YY. Alarmingly, when rats digest artificial sweeteners, both GLP-1 and PYY aren’t released and appetite suppression is not observed. In a recent study, rats that were fed artificially sweetened yogurt consumed more food than those given sugar-sweetened yogurt.[17]

Desensitizes Sweet Receptors

It’s also possible that artificial sweeteners make us crave sweeter food by altering our palate. Artificial sweeteners, which can be thousands of times sweeter than sugar, have the potential to overstimulate our sweet taste receptors. 

According to Dr. David Ludwig, a leading obesity specialist and professor at Harvard Medical School, frequently consuming super-intense sweeteners can make naturally sweet foods, like fruit, taste less pleasurable, while making savory food, like vegetables, frankly inedible. Over time you can end up replacing healthy, real food with artificially flavored, processed foods that deliver little nutritional value. 

Damaging to Gut Bacteria

While non-caloric artificial sweeteners may seemingly be good for gut bacteria since sugar is known to feed bacterial overgrowth, the research states otherwise. A study specifically examining the effects on artificial sweeteners on gut bacteria found them to be toxic due to causing inhibition of good gut microbes.[34] Furthermore, additional studies such as one by a group of Israeli scientists, found increased glucose intolerance and alterations in the intestinal microbiota in those who consumed artificial sweeteners.[35]

The “Low Fat” Effect

Another concern is that artificial sweeteners can lead to overeating as people replace lost calories through other sources. Have you ever thought “I’m having diet soda… so I can have that extra cookie”?  

In addition to altering the level of guilt we associate with food, studies show that diet-related labels, such as “sugar-free” or  “low-carb” distort our perception of serving size and calories per serve. A well-known study including 360 university students proved this theoretical phenomenon to be true. Participants were presented with one bowl labeled “Low-Fat M&Ms” and another bowl labeled “Regular M&Ms.” Each participant was then asked to serve themselves an average serving size and estimate how many calories were in their serve. Participants ate 28% more M&Ms when labeled “low fat,” served up 25% more and estimated 300 fewer calories than regular M&Ms.[18]

Increased Risk of Type 2 Diabetes

Artificial sweeteners are often recommended to diabetes as a safe alternative to sugar as studies have shown that it does not raise blood glucose or insulin levels.[19,20] However, a new study that followed over 60,000 European women for 18 years found that consuming artificial sweeteners more frequently and for a longer period was associated with a higher risk of Type 2 Diabetes.[21] Participants who reported consuming artificial sweeteners “always or almost always” had the highest number of risk factors, and the magnitude of the association remained statistically significant after adjusting for BMI. 

The same study also found that daily consumption of diet soda was associated with a 36% greater risk of suffering from any metabolic syndrome and a 67% greater risk of developing type 2 diabetes compared with non-consumption.[21] 

Side note- I once had a physician for a client who just could not figure out for the life of him why his blood sugar was so incredibly high for years. So, I tracked his intake for 6 months. I can tell you with 100% certainty that he did not consume a single drop of sugar. He also rarely ate processed foods. BUT, every single meal included at least 1-2 servings of an artificial sweetener. He added it to his coffee, yogurt, oatmeal etc. Sadly, he ended up with a diagnosis of Type 2 Diabetes despite his desperate attempt to prevent all chronic health conditions. Perfect proof that much of what the public is taught about “proper nutrition” is not valid information. Companies often care more about making a buck than actually improving consumer health.

OK, back to the research.

Various researchers have investigated the effects of specific sweeteners on risk factors for Type 2 Diabetes, including glucose intolerance and insulin response. A 2016 study found that aspartame is associated with impaired glucose tolerance among individuals with obesity.[22] Other studies have confirmed that long-term consumption of artificial sweeteners can impair glucose regulation and lead to insulin resistance by altering the gut microbiota in rodents and humans.[23,24] 

Contribute to Cardiovascular Disease

A diet high in sugar is associated with cardiovascular disease, but artificial sweeteners may be just as dangerous for your heart health. Recent long-term studies have found that regular consumption of diet soft drinks may increase your risk of vascular disease, including heart attack and stroke.[25,26]

A 2011 study aimed to understand why and found that long-term consumption of aspartame, saccharin, and acesulfame potassium accelerates the accumulation of plaque (made from fatty acids and cholesterol) within the arteries. Over time this buildup of plaque can narrow the arteries and restrict blood flow leading to a stroke or heart attack. Artificial sweeteners are thought to impair the structure and function of proteins that are essential in clearing lipids and cholesterol from the body.[27] These proteins, primarily high-density lipoproteins (HDL), also have an anti-aging effect on our blood vessels.

Triggers Migraines 

Within my practice, common artificial sweetener side effects include diarrhea, abdominal pain, joint pain, cramping, a burning sensation while urinating, constipation, and headaches. While there has been limited research into gastrointestinal symptoms, artificial sweeteners have been linked to migraines in several clinical cases. 

The first case was published in 1986, shortly after the FDA approved aspartame. A doctor from California reported a woman suffering from migraines that he suspected could be attributed to the consumption of aspartame tablets and artificially sweetened soft drinks. The migraines completely resolved after ten days of avoidance and returned within 1.5 hours of consuming an aspartame solution.[28] 

In 2008, a case series reported six patients who suffered from dermatitis after regularly consuming more than two liters of diet cola per day. Five of the six patients also reported migraines, and all six patients had positive reactions to formaldehyde in a skin patch test. Following expert counseling on avoiding artificial sweeteners, all six patients showed improvement in their symptoms at an 8 and 12 week follow-up. Four of the six patients accidentally resumed the consumption of artificial aspartame, and symptoms resurfaced at the third follow-up.[29]

As mentioned earlier, aspartame is converted into formaldehyde within the body, which is known to bind with nucleic acids (DNA) and alter their structure.[30] The authors of this study believe formaldehyde can accumulate within the body. Therefore, people with an allergy or sensitivity to formaldehyde can experience both contact dermatitis and migraines. 

What Foods Are Artificial Sweeteners Commonly Found in? 

Artificial sweeteners are tucked into a variety of processed food from yogurts and cereals to canned foods, sports drinks, and chewing gums. Most foods that contain artificial sweeteners are labeled as “diet” or “reduced sugar,” but that’s not always the case. You may even find the fake stuff in foods that claim to have natural ingredients. Therefore, it’s still best to check the ingredient list of the product. When reviewing the ingredients, an artificial sweetener will appear under its chemical name. For example, Splenda will appear as sucralose. Equal will appear as Aspartame. 

List of different types of artificial sweeteners, their common brand names, and the amount of sweetness they consist of when compared to sugar.

Common Products Containing Artificial Sweeteners:

  • Sugar-free drinks such as soda, juices, and cordials
  • Low-calorie sports drinks and hydration beverages
  • Diet dairy products such as yogurts, flavored milks, and ice cream
  • Sugar-free sauces, particularly ketchup
  • Diet salad dressing
  • Low-carb baked food such as muffins and bread, particularly wholemeal varieties
  • Cereal, particularly granolas
  • Sugar-free candy and chewing gum
  • Medications such as cough syrups and children’s capsules

What’s the Best Answer? 

The safest option is to avoid added sugar altogether. Sugar is unequivocally linked to various health issues: obesity, chronic inflammation, heart disease, type 2 diabetes, and even cancer.

But, I get it; you’re human right? And going cold turkey on sugar is sometimes a very difficult feat. So, if you do treat yourself, opt for natural varieties like raw honey, agave nectar, coconut sugar or pure maple syrup. 

Natural sugars generally have more nutritional value than refined sugar, which is 100% empty calories. For example, high-quality raw honey contains potent antioxidants, like phenolic acids, that prevent cellular damage and have anti-inflammatory properties. 

With that said, natural sugars are equally high in calories and will cause blood sugar spikes, insulin peaks and sabotage attempts to control weight. It’s, therefore, best to limit natural sugars to no more than 1 or 2 teaspoons per day. 

Better yet, satisfy your sweet craving with fruit. The fruit is a natural sweetener packed full of vitamins and antioxidants. Add a banana to your morning oats, sweeten your smoothie with mixed berries, or swap your afternoon chocolate for a juicy peach. With a few small adjustments, you can break your sweet habit and say goodbye to sugar cravings altogether. 

What If I’m Diabetic?

If you’re trying to manage diabetes or watching your weight, working with a nutrition professional to design an individualized eating approach is your best option. When added sugar is kept to a minimum and protein, fat and carbohydrate are properly balanced, that is when you will experience the most success when it comes to weight management/blood sugar control.

The best option for second place is finding a natural low-calorie sweetener that you enjoy. The FDA has approved two natural plant-derived low-calorie sweeteners, including extracts obtained from the leaves of Stevia rebaudiana plants and extracts from Siraitia grosvenorii, also known as monk fruit. 

Unlike artificial sweeteners and sugar, Stevia has been shown to have multiple benefits such as improving insulin sensitivity and blood sugar levels. [31] Monk fruit has also been shown to have antioxidant, anti-microbial, glucose-lowering, and liver-protective properties.[32]

If you’re looking for new, healthy alternatives to your favorite sweet treats, check out my previous article discussing healthy swaps.

Take Away: Are Artificial Sweeteners Safe?

While the FDA has approved six different artificial sweeteners, we really don’t know how the consumption of these chemicals will affect our health in the long run.

My gut tells me (pun intended!) that down the line, we will continue to discover more dangers and adverse side effects from the frequent consumption of artificial sweeteners. After all, if hundreds upon hundreds of the individuals that I coach experience such negative side effects after minimal consumption, I can’t help but assume that this will manifest into unwanted health conditions down the road.

It also remains unclear how these super-sweet compounds will affect our children, especially with fetal exposure. Based on the current evidence and level of industry-funded research [33], my best advice is to steer clear of any artificial sweetener made in a laboratory, especially when pregnant.

Why risk exposing yourself, or your loved ones, to potentially hazardous chemicals when we have natural alternatives readily available?



[2] https://www.ncbi.nlm.nih.gov/pubmed/11615708/

[3] https://www.nature.com/articles/227296a0

[4] http://science.sciencemag.org/content/167/3920

[5] https://www.ncbi.nlm.nih.gov/pubmed/71398?dopt=Abstract

[6] https://academic.oup.com/annonc/article/15/10/1460/170200

[7] https://www.ncbi.nlm.nih.gov/pubmed/5411626

[8] https://jamanetwork.com/journals/jama/article-abstract/360615

[9] https://www.sciencedirect.com/science/article/pii/S0022534717591041

[10] https://www.ncbi.nlm.nih.gov/pubmed/17119233/

[11] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1964906/

[12] https://www.ncbi.nlm.nih.gov/pubmed/26202345

[13] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2892765/

[14] https://touroscholar.touro.edu/cgi/viewcontent.cgi?article=1053&context=sjlcas

[15] https://www.ncbi.nlm.nih.gov/pubmed/18535548

[16] https://www.ncbi.nlm.nih.gov/pubmed/3714671/

[17] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3985091/

[18] https://papers.ssrn.com/sol3/papers.cfm?abstract_id=2474336

[19] https://www.ncbi.nlm.nih.gov/pubmed/20420761

[20] https://www.ncbi.nlm.nih.gov/pubmed/21245879


[22] https://www.ncbi.nlm.nih.gov/pubmed/27216413/



[25] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3514985/

[26] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4371001/

[27] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3887604/

[28] http://agris.fao.org/agris-search/search.do?recordID=US8724688



[31] https://www.ncbi.nlm.nih.gov/pubmed/23140911

[32] https://www.ncbi.nlm.nih.gov/pubmed/24636058

[33] https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0162198

[34] https://www.mdpi.com/1420-3049/23/10/2454/htm

[35] https://www.nature.com/articles/nature13793?tdc_uid=921043