When you hear the word “artificial” in the context of nutrition, you might immediately think “bad.” But here’s something that may come as a surprise: there isn’t much evidence to support the idea that artificial sweeteners are bad for you.
More often than not, the misconceptions around artificial sweeteners stem from lower-quality studies, a blatant misunderstanding of research by the media and the general public, and our inherent stubborn desire to believe that all things natural are good, while all things artificial must be bad.
Here’s what we know about artificial sweeteners, and why they aren’t as big of a problem as you may have been led to believe.
What are artificial sweeteners?
Any time you eat packaged foods that are labeled as “diet” or “zero calories” but still taste sweet and delicious, you’re likely consuming some form of artificial sweetener.
Artificial sweeteners are substances that taste sweet and are often used as sugar substitutes. Artificial sweeteners are non-nutritive, meaning they carry no significant nutritional benefits. They’re also very low in calories, which means that they are often used by people looking to cut down their calorie intake (ie: those who are trying to lose weight and/or cut fat).
Some common artificial sweeteners include:
- Sucralose
- Saccharin
- Aspartame
- Acesulfame Potassium (Ace-K)
Another honorable mention is stevia. Unlike the others on this list, stevia is a natural substance found in the Stevia rebaudiana plant, so it’s not an artificial sweetener, but it is a non-nutritive sweetener. It’s used so often as a sugar substitute that it’s well worth mentioning it in the conversation.
Are artificial sweeteners dangerous? No, according to the research.
Many people are hesitant to substitute real sugar for artificial sweeteners out of the fear that something "artificial" is automatically going to be "bad" for them.
There are several misunderstandings out there due to bad scientific reporting and media misconceptions. For example, we’re betting you’ve heard that artificial sweeteners can cause cancer, or that artificial sweeteners can seriously mess with your gut health. But when you take a closer look at the research, the results come up with something that might be surprising: as far as the studies show, artificial sweeteners are not dangerous for humans.
Do artificial sweeteners cause cancer?
Fears around artificial sweeteners and cancer can be traced back to 1970, when a study showed that rats fed massive amounts of saccharin and cyclamate had an increased risk of developing bladder tumors.[1] Various studies in rats throughout the 1970's showed similar findings.[2][3]
Based on these animal studies, in 1981 the US National Toxicology Program's "Report on Carcinogens" listed saccharin as a substance reasonably anticipated to be a human carcinogen.
Now, at this point, there are two important things to keep in mind. First, while animal studies are a valuable part of scientific research, the data we get from animals does not immediately translate to humans. And second, these rat studies used artificial sweeteners in incredibly high doses, which would be extremely hard to replicate in humans.
In the decades that followed, after further studies and more data on saccharin emerged, scientists realized that the mechanisms by which tumors show up in rats is not applicable to humans.[4] And in 2000, the National Toxicology Program removed saccharin from the list of carcinogens stating: "This decision is based on the perception that the observed urinary-bladder tumors in rats arise by mechanisms not relevant to humans, and the lack of data in humans suggesting a carcinogenic hazard."[4]
In other words, the initial findings from those early experimental animal studies simply don't apply to the human body.
Although saccharin was ultimately vindicated, years of bad press and continued references to the old rat studies by modern health gurus seems to have created an unbreakable link between cancer and artificial sweeteners in the public consciousness. Therefore, all artificial sweeteners - from saccharin to sucralose to aspartame - frequently fall under the dark shadow of fear and rampant speculation.
These misconceptions are not supported by epidemiological studies in humans. For example, a review from 2004 found that, despite the evidence of bladder cancer-inducing effects of saccharin in rats, there’s no evidence of the same thing happening in humans, nor is there any evidence that aspartame is carcinogenic despite the “rather unscientific assumptions” that say otherwise.[5]
A more recent analyses from 2022 showed no association between low-calorie sweetener use and overall cancer mortality risk in humans.[6] Layne Norton breaks down the results of this study on his YouTube channel if you want to get into the details.
Ultimately, there have been multiple studies that fail to show an association between artificial sweetener intake and cancer in humans.[7][8][9][10]
The key takeaway here: despite what you might have read in the news headlines, there isn’t any clinical evidence to suggest that artificial sweeteners cause cancer in humans.
What about artificial sweeteners and gut health?
There’s another major falsehood circulating that artificial sweeteners can harm your gut microbiome, which is the community of bacteria that live in your intestines.
The main concern here is the idea that artificial sweetener consumption can lead to “leaky gut,” or increased gut permeability. What this means: the lining of your intestines acts as a semipermeable barrier that allows the right nutrients to get out of your gut and into your bloodstream, where they can then be delivered to the cells that need them. But the permeability of your gut lining is dependent on factors like your gut microbiome, and some in vitro studies[11] on isolated bacteria have shown that high doses of various artificial sweeteners may be harmful to certain gut bacteria species.
Remember, these are studies on cells in a petri dish. Again, while these type of studies can be a valuable part of scientific research, the results from such studies cannot be directly applied to human physiology. Unfortunately, our news media doesn't understand how science works and generally misreports these findings with scary headlines that get passed around on social media.
Should we all be terrified and throw out our diet sodas? Not so fast. When it comes to human subjects, the evidence is much less convincing:
- A 2019 study[12] on 34 healthy male volunteers evaluated the effects of high-dose sucralose capsules (780mg per day.) They found that this high dose of sucralose did not alter glycemic control, insulin resistance, or gut microbiome. (For reference, 1 packet of Splenda contains approx 12mg of sucralose.)
- A 2021 study[13] looked at the gut microbiome of healthy adults who were administered high doses of pure saccharin. These researchers also found that the saccharin supplementation had no significant effect on glucose response or the gut microbiome.
- A 2022 study[14] looked at the gut microbiome of healthy adults who were administered sucralose for 10 weeks. The authors found an increase in a single strain of bacteria, but we don't know if that outcome has negative effects or if it may actually have benefits. Layne Norton dives deep on this study here if you want to watch.
- Another 2022 study[15] compared saccharin, sucralose, aspartame, and stevia in 120 healthy adults. Some changes were observed in the gut microbiome, however we don't know if these changes are negative or may be favorable. Again, Layne breaks down this study if you want to hear more.
Do artificial sweeteners lead to weight gain?
Finally, there are some people who like to push the idea that those who consume more artificial sweeteners tend to be overweight. But taking a closer look at the research around this topic, this doesn’t seem to be the case at all.
One reason this misconception exists is because of the effects that people think artificial sweeteners have on your hormones and thus, your eating behaviors. For example, some people claim that artificial sweeteners "trick" your body into thinking you're eating sugar and this causes your body to pump out insulin, which "leads to fat storage". Or that drinking diet soda somehow triggers your cravings for something sweet, thus leading to subsequent overeating.
However, there is no good evidence to support this claim. Studies have actually shown that the consumption of diet soda versus water led to better results as far as calorie intake goes.[16]
What's more, there's plenty of evidence that non-nutritive sweeteners can help with weight loss and maintenance.[17][18][19]
Finally, we know that artificial sweeteners do not affect glycemia.[20]
At the end of the day, the one thing that really matters for weight lost or gain is energy balance, aka calories in vs calories out. Real sugar is abundant in the Western diet and has been linked to weight gain and obesity due to its high energy density.[21]
By replacing calorie-dense sugar with a sugar substitute that is virtually zero calories, it can absolutely make a difference in calorie control (and subsequent weight changes) — and there’s no evidence that artificial sweeteners are the reason that someone ends up consuming more calories.
Why artificial sweeteners have such a bad reputation
So if all the quality research doesn’t actually show that there’s anything inherently dangerous about artificial sweeteners, then why do so many people believe that they’re bad?
The failure of the “appeal to nature” fallacy
A lot of this comes down to the “appeal to nature” logical fallacy (also known as the naturalistic fallacy).
As we mentioned before, it’s a common and widespread assumption that “natural” is good, while “artificial” is bad, especially when it comes to the food that you put in your body. However, this bias doesn't take into account dosing. At the end of the day, the dose makes the poison.
For example, cyanide - a deadly poison - is found in apple seeds. Will you die from eating a few apple seeds? No, since the amount of cyanide is too low to cause harm.
What about bananas? Bananas, along with other foods like avocados, nuts, and oranges, are high-potassium foods that can cause hyperkalemia in some people with impaired kidney function.[22]
Finally, did you know that you can overdose on water? Yes, fatal water intoxication is a real thing.[23]
So does this mean that apple seeds, bananas, and water are super scary and dangerous? No, of course not. It simply means that there are multiple factors to consider when assessing whether or not a substance is "good" or "bad", and only considering whether a substance is natural or artificial doesn't tell the whole story.
Poor reporting and media circuses
Another major issue is that our media simply isn't qualified to be interpreting scientific research. Unfortunately, this doesn't stop them from running misinformed headlines and spreading FUD (fear, uncertainty, and doubt.)
News articles often conflate correlation with causation, lack context when it comes to in vitro studies versus in vivo studies, and generally get just about everything wrong when it comes to interpreting scientific data.
This is a recipe for disaster, as this misinformation tends to spread like wildfire and the result is a misinformed public.
Ultimately, that's why we write these blogs.
So bottom line: are artificial sweeteners bad?
No. There’s no good evidence to suggest that drinking a diet soda or consuming an artificially sweetened protein shake are going to cause cancer, lead to weight gain, or negatively impact your gut microbiome. In fact, using artificial sweeteners can be a great strategy to cut down on excess calories and aid in weight loss.
References
1. Price, J M et al. “Bladder tumors in rats fed cyclohexylamine or high doses of a mixture of cyclamate and saccharin.” Science (New York, N.Y.) vol. 167,3921 (1970): 1131-2. doi:10.1126/science.167.3921.1131
2. Reuber, M D. “Carcinogenicity of saccharin.” Environmental health perspectives vol. 25 (1978): 173-200. doi:10.1289/ehp.7825173
3. Chowaniec, J, and R M Hicks. “Response of the rat to saccharin with particular reference to the urinary bladder.” British journal of cancer vol. 39,4 (1979): 355-75. doi:10.1038/bjc.1979.68
4. Report on Carcinogens, Fifteenth Edition
5. Weihrauch, M R, and V Diehl. “Artificial sweeteners--do they bear a carcinogenic risk?.” Annals of oncology : official journal of the European Society for Medical Oncology vol. 15,10 (2004): 1460-5. doi:10.1093/annonc/mdh256
6. Fulgoni, Victor L 3rd, and Adam Drewnowski. “No Association between Low-Calorie Sweetener (LCS) Use and Overall Cancer Risk in the Nationally Representative Database in the US: Analyses of NHANES 1988-2018 Data and 2019 Public-Use Linked Mortality Files.” Nutrients vol. 14,23 4957. 22 Nov. 2022, doi:10.3390/nu14234957
7. Gallus, S et al. “Artificial sweeteners and cancer risk in a network of case-control studies.” Annals of oncology : official journal of the European Society for Medical Oncology vol. 18,1 (2007): 40-44. doi:10.1093/annonc/mdl346
8. Bosetti, Cristina et al. “Artificial sweeteners and the risk of gastric, pancreatic, and endometrial cancers in Italy.” Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology vol. 18,8 (2009): 2235-8. doi:10.1158/1055-9965.EPI-09-0365
9. Magnuson, B A et al. “Aspartame: a safety evaluation based on current use levels, regulations, and toxicological and epidemiological studies.” Critical reviews in toxicology vol. 37,8 (2007): 629-727. doi:10.1080/10408440701516184
10. Marinovich, Marina et al. “Aspartame, low-calorie sweeteners and disease: regulatory safety and epidemiological issues.” Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association vol. 60 (2013): 109-15. doi:10.1016/j.fct.2013.07.040
11. Shil, Aparna, and Havovi Chichger. “Artificial Sweeteners Negatively Regulate Pathogenic Characteristics of Two Model Gut Bacteria, E. coli and E. faecalis.” International journal of molecular sciences vol. 22,10 5228. 15 May. 2021, doi:10.3390/ijms22105228
12. Thomson, Pamela et al. “Short-term impact of sucralose consumption on the metabolic response and gut microbiome of healthy adults.” The British journal of nutrition vol. 122,8 (2019): 856-862. doi:10.1017/S0007114519001570
13. Serrano, Joan et al. “High-dose saccharin supplementation does not induce gut microbiota changes or glucose intolerance in healthy humans and mice.” Microbiome vol. 9,1 11. 12 Jan. 2021, doi:10.1186/s40168-020-00976-w
14. Méndez-García, Lucía A et al. “Ten-Week Sucralose Consumption Induces Gut Dysbiosis and Altered Glucose and Insulin Levels in Healthy Young Adults.” Microorganisms vol. 10,2 434. 14 Feb. 2022, doi:10.3390/microorganisms10020434
15. Personalized microbiome-driven effects of non-nutritive sweeteners on human glucose tolerance
16. Piernas, Carmen et al. “Does diet-beverage intake affect dietary consumption patterns? Results from the Choose Healthy Options Consciously Everyday (CHOICE) randomized clinical trial.” The American journal of clinical nutrition vol. 97,3 (2013): 604-11. doi:10.3945/ajcn.112.048405
17. Rogers, Peter J, and Katherine M Appleton. “The effects of low-calorie sweeteners on energy intake and body weight: a systematic review and meta-analyses of sustained intervention studies.” International journal of obesity (2005) vol. 45,3 (2021): 464-478. doi:10.1038/s41366-020-00704-2
18. Rogers, P J et al. “Does low-energy sweetener consumption affect energy intake and body weight? A systematic review, including meta-analyses, of the evidence from human and animal studies.” International journal of obesity (2005) vol. 40,3 (2016): 381-94. doi:10.1038/ijo.2015.177
19. Stamataki, Nikoleta S et al. “Effects of the Daily Consumption of Stevia on Glucose Homeostasis, Body Weight, and Energy Intake: A Randomised Open-Label 12-Week Trial in Healthy Adults.” Nutrients vol. 12,10 3049. 6 Oct. 2020, doi:10.3390/nu12103049
20. Nichol, Alexander D et al. “Glycemic impact of non-nutritive sweeteners: a systematic review and meta-analysis of randomized controlled trials.” European journal of clinical nutrition vol. 72,6 (2018): 796-804. doi:10.1038/s41430-018-0170-6
21. Bray, George A, and Barry M Popkin. “Dietary sugar and body weight: have we reached a crisis in the epidemic of obesity and diabetes?: health be damned! Pour on the sugar.” Diabetes care vol. 37,4 (2014): 950-6. doi:10.2337/dc13-2085
22. Hyperkalemia
23. Farrell, D J, and L Bower. “Fatal water intoxication.” Journal of clinical pathology vol. 56,10 (2003): 803-4. doi:10.1136/jcp.56.10.803-a
