Are Artificial Sweeteners Helpful or Harmful? A Look at the Pros and Cons of Sugar Substitutes

Artificial sweeteners, also known as sugar substitutes or non-nutritive sweeteners, have risen in popularity since their discovery over the previous century. However, concerns about their safety and potential adverse effects have also increased in recent years. 

While many people love to use those little pink and yellow packets to sweeten their drinks, they may not be as helpful to health as once thought. If you’ve ever wondered whether or not artificial sweeteners are bad for you, learn more in this article about the pros and cons of consuming the top six that are on the market today. 

The Basics of Artificial Sweeteners

Currently, the Food and Drug Administration (FDA) has approved the following six artificial sweeteners as safe for human consumption: 

• Saccharin (found in Sweet’N Low)
• Aspartame (found in NutraSweet and Equal)
• Sucralose (found in Splenda)
• Neotame (also found in NutraSweet)
• Acesulfame-K (found in Sweet One)
• Advantame (used primarily in the food and beverage industry)

These non-nutritive sweeteners provide zero to very few calories and no sugar but are hundreds to thousands of times sweeter than table sugar, based on their chemical structures. 

Although all six artificial sweeteners have different molecular structures, they all function in the same way. These chemicals activate the sweet receptors on our taste buds similarly to how sugar would — in essence, “tricking” our taste buds. 

Unlike sugar, artificial sweeteners don’t provide calories or nutritional value because our digestive system can’t break them down and metabolize them. 

For this reason, the colorful packets became somewhat of a miracle food around the 1980s for people with diabetes and those trying to lose weight. However, the decades of research following their rise in popularity has indicated that artificial sweeteners may be doing more harm than good. 

The Pros of Artificial Sweeteners

Although most of the research on artificial sweeteners is negative, there are a couple of positive attributes, mainly because they can replace high amounts of sugar in the diet.

1. Reduces Caloric and Sugar Intake

For individuals who consume many sugar-sweetened beverages and foods, artificial sweeteners may be a good step to wean off those items. Similarly, someone with diabetes who currently eats a high-sugar diet may see beneficial effects on their blood sugar after switching to sugar substitutes. 

Some artificial sweeteners have been found not to affect blood glucose. However, as we’ll see, longer-term research has shown negative impacts of the sugar substitutes on glucose metabolism.   

2. Reduces Dental Caries

Artificial sweeteners may also improve dental health and reduce cavities in adults and children prone to consuming sugar-sweetened drinks. 

In a review published in September 2017 in the Journal of Nutrition, most of the studies reviewed found that artificially sweetened beverages reduced the risk of dental caries and made the oral pH less acidogenic. As an acidic oral pH is a cause of tooth decay, this indicates that artificial sweeteners may benefit oral health.

The Cons of Artificial Sweeteners

Although there are some potential benefits to consuming non-nutritive sweeteners, there are also quite a few adverse effects that have been studied. Initially, questions about adverse effects arose from research indicating that the artificial sweeteners saccharin and cyclamate were carcinogenic to lab animals’ bladders. 

Due to this, cyclamate was banned from the U.S. food supply in 1969, and saccharin was prohibited from 1981 to 2000. However, the FDA reversed the ban on saccharin due to insufficient claims that the chemical was carcinogenic in humans, though cyclamate remains banned for other reasons.

1. May Cause Weight Gain

Although many people use artificial sweeteners to lose weight, these sugar substitutes have actually been linked to weight gain. While it sounds counterintuitive, artificial sweeteners play a negative role in metabolism, leading to an increased risk of obesity or weight gain. 

In a meta-analysis published in the Canadian Medical Association Journal in July 2017, the pooled results from 30 cohort studies found a link between increased consumption of artificial sweeteners and increased BMI, weight, waist circumference, and obesity rates. However, the randomized controlled trials that were analyzed did not find the same association. 

Researchers tested long-term artificial sweetener consumption in rats in a study published in Nutrients in April 2019. Rats who drank sucralose for four months had significant increases in the hormones GIP and GLP-1, which led to greater body weight gain and increased area of adipocytes. Large adipocytes, or fat cells, upregulate pro-inflammatory pathways, which increases the risk of obesity.

2. Disrupts Satiety Signals

Another mechanism behind artificial sweeteners’ link to weight gain is because they reduce satiety signals, which then increases appetite and hunger and alters taste preferences.

Due to the tricking of the taste buds that occurs when one consumes artificial sweeteners, metabolic signaling is altered. This includes nutrient-sensing pathways that regulate hormones and fat storage. 

However, the brain cannot be tricked like the taste buds are. After consuming real sugar, an intricate pathway is activated, which begins when tongue cells send information to the brain via cranial nerves. This allows the brain to release dopamine, a feel-good neurotransmitter that evolved to reward our ancestors when they found high-sugar food, which was hard to come by in those times.

In addition, the hormone leptin is released, which regulates satiety and tells the brain when you’re full after consuming caloric foods. 

When an artificially sweetened product is consumed, the reward pathway is stimulated, but there is no reward — the body doesn’t receive any calories, and satiety cues become dysregulated. This can lead to overeating because leptin isn’t telling the brain that it has received nourishment. 

Sugar cravings can also be increased after using artificial sweeteners because the substitutes are exponentially sweeter, and repeated exposure raises the threshold of sweet taste preference.

3. Alters Glucose Metabolism

Artificial sweetener consumption is linked to dysfunctional glucose metabolism, which increases blood sugar and may increase the risk of type 2 diabetes. 

In a study published in December 2019 in Nutrients, adults who consumed sucralose in an amount that approximated a can of diet soda experienced a 30% increase in glucose area under the curve (AUC) compared to when they consumed water. 

Incremental AUC is used to measure the total increase in blood glucose after an oral glucose tolerance test. The effects were especially pronounced in individuals with obesity. 

Chronic consumption of artificial sweeteners is associated with an increased incidence of type 2 diabetes, as seen in a Diabetes Care study in April 2009. This study of over 6,800 adults found that daily diet soda consumption was linked to a 67% increased risk of developing type 2 diabetes compared to those who never drank diet soda.

4. Negatively Impacts the Gut Microbiome

Although artificial sweeteners do not get metabolized, they do interact with the bacteria in our gut. 

In a study published in Nature in October 2014, researchers supplemented the drinking water of mice with saccharin. Compared to controls, the mice who had the saccharin water experienced dysbiosis in the gut, indicated by an underrepresentation of healthy bacteria and an overgrowth of bad bacteria, including species that have been linked to type 2 diabetes. 

These results indicate that the gut microbiome may be another mechanism by which artificial sweeteners impair glucose metabolism. 

In addition to causing gut dysbiosis, artificial sweeteners may be associated with increasing the risk of inflammatory bowel disease (IBD), which is classified by either ulcerative colitis or Crohn’s disease. 

Published in Inflammatory Bowel Disease in April 2018, researchers looked at the effects of sucralose on mice genetically prone to Crohn’s disease. After six weeks of supplementation with Splenda, the mice had increased ileal myeloperoxidase levels, an inflammatory enzyme in the small intestine. 

The mice also had increased growth of the dysbiotic Proteobacteria, which is linked to increased intestinal permeability, also known as leaky gut. Dysbiosis, intestinal permeability, and inflammation in the gut are associated with worse IBD symptoms. However, studies have not yet shown that artificial sweeteners are causally linked to IBD in humans. 

Key Takeaway: Are Artificial Sweeteners Helpful or Harmful?

• There are currently six approved artificial sweeteners on the market today that the FDA recognizes as safe for consumption. Artificial sweeteners can reduce caloric and sugar intake and reduce the prevalence of cavities; however, there are some downsides to be aware of.
• Although artificial sweeteners do not contain sugar, they can alter glucose metabolism and increase body weight by disrupting satiety signals, hormones, and neurotransmitter reward pathways in the brain.
• In animal studies, artificial sweeteners alter the gut microbiome, causing dysbiosis and increasing the risk of gastrointestinal disorders.

References:

Azad MB, Abou-Setta AM, Chauhan BF, et al. Nonnutritive sweeteners and cardiometabolic health: a systematic review and meta-analysis of randomized controlled trials and prospective cohort studies. CMAJ. 2017;189(28):E929-E939. doi:10.1503/cmaj.161390

Bokulich NA, Blaser MJ. A bitter aftertaste: unintended effects of artificial sweeteners on the gut microbiome. Cell Metab. 2014;20(5):701-703. doi:10.1016/j.cmet.2014.10.012

Lohner S, Toews I, Meerpohl JJ. Health outcomes of non-nutritive sweeteners: analysis of the research landscape. Nutr J. 2017;16(1):55. Published 2017 Sep 8. doi:10.1186/s12937-017-0278-x

Ma J, Bellon M, Wishart JM, et al. Effect of the artificial sweetener, sucralose, on gastric emptying and incretin hormone release in healthy subjects. Am J Physiol Gastrointest Liver Physiol. 2009;296(4):G735-G739. doi:10.1152/ajpgi.90708.2008

Nettleton JA, Lutsey PL, Wang Y, Lima JA, Michos ED, Jacobs DR Jr. Diet soda intake and risk of incident metabolic syndrome and type 2 diabetes in the Multi-Ethnic Study of Atherosclerosis (MESA). Diabetes Care. 2009;32(4):688-694. doi:10.2337/dc08-1799

Nichol AD, Salame C, Rother KI, Pepino MY. Effects of Sucralose Ingestion versus Sucralose Taste on Metabolic Responses to an Oral Glucose Tolerance Test in Participants with Normal Weight and Obesity: A Randomized Crossover Trial. Nutrients. 2019;12(1):29. Published 2019 Dec 20. doi:10.3390/nu12010029

Rodriguez-Palacios A, Harding A, Menghini P, et al. The Artificial Sweetener Splenda Promotes Gut Proteobacteria, Dysbiosis, and Myeloperoxidase Reactivity in Crohn's Disease-Like Ileitis. Inflamm Bowel Dis. 2018;24(5):1005-1020. doi:10.1093/ibd/izy060

Sánchez-Tapia M, Martínez-Medina J, Tovar AR, Torres N. Natural and Artificial Sweeteners and High Fat Diet Modify Differential Taste Receptors, Insuln, and TLR4-Mediated Inflammatory Pathways in Adipose Tissues of Rats. Nutrients. 2019;11(4):880. Published 2019 Apr 19. doi:10.3390/nu11040880

Suez J, Korem T, Zeevi D, et al. Artificial sweeteners induce glucose intolerance by altering the gut microbiota. Nature. 2014;514(7521):181-186. doi:10.1038/nature13793

Suez J, Korem T, Zilberman-Schapira G, Segal E, Elinav E. Non-caloric artificial sweeteners and the microbiome: findings and challenges. Gut Microbes. 2015;6(2):149-155. doi:10.1080/19490976.2015.1017700

Yang Q. Gain weight by "going diet?" Artificial sweeteners and the neurobiology of sugar cravings: Neuroscience 2010. Yale J Biol Med. 2010;83(2):101-108. PMCID: PMC2892765.