Scientific studies strongly suggest that artificial sweeteners, once thought to be safe alternatives to sugar, are linked to significant health risks. Key findings include increased risks of cardiovascular disease, stroke, type 2 diabetes, metabolic syndrome, cognitive decline, and potential carcinogenicity.1 2 Artificial sweeteners discussed include erythritol, sucralose, and aspartame, which can alter gut microbiota,3 increase inflammation, and cause blood clotting.
A 2025 observational study further supports many other research findings showing a strong correlation between artificial sweetener intake and mental decline.4 Among adults under age 60 in the study, higher intake of several sweeteners–aspartame, saccharin, acesulfame-K, erythritol, sorbitol, and xylitol–was linked with a quicker drop in overall cognitive performance, with the clearest effects showing up in memory and verbal fluency. When researchers examined total intake across multiple artificial sweeteners, people in the highest-consumption group showed a faster decline in verbal fluency and global cognition. This pattern appeared in participants without diabetes, and the decline was even more pronounced in those with diabetes. The trend remained steady across the 8-year follow-up.
Artificial Sweeteners and Vision Problems
There are indications that intake of artificial sweeteners can have a negative effect on vision. Some potential concerns include increased light sensitivity, blurred vision, and, in rare cases, more severe issues like blindness. Artificial sweeteners such as aspartame and cyclamates have been specifically mentioned as potentially having negative vision effects.
A study published online in the September/October 2018 issue of Clinical and Experimental Ophthalmology suggests that drinking diet soda could be linked to a higher risk of proliferative diabetic retinopathy.5 In the clinical group of participants with diabetes, those who reported consuming more than four cans (about 1.5 liters) of diet soft drinks per week were found to have about twice the likelihood of having proliferative diabetic retinopathy compared with lower or non-consumers.
Gut Microbiota
A study in 2014 in Nature reports that commonly used artificial sweeteners may worsen blood-sugar control by changing the gut microbiome. In mouse experiments, the authors found that artificial sweetener consumption led to glucose intolerance, and that this effect disappeared with antibiotics and could be transferred to germ-free mice via fecal microbiota transplant–suggesting the microbiome was a key driver. They also identified artificial sweetener-associated shifts in microbial functions linked to metabolic disease risk, and observed similar artificial sweetener-related microbiome changes and glucose intolerance in a subset of healthy human participants.6
In a separate study, researchers randomly selected and analyzed 172 people and found noticeable shifts in their gut bacteria–most notably higher levels of the Actinobacteria phylum, Deltaproteobacteria, and the Enterobacteriaceae family.7
There are a few theories about how artificial sweeteners may affect the gut microbiome. For instance, saccharin may interfere with normal protein digestion in the intestines, which could leave more material for gut bacteria to break down–potentially increasing bacterial activity and altering the balance of microbes.8
Other research suggests artificial sweeteners may reduce the gut’s normal “housekeeping” waves of movement (the migrating motility complex) in both healthy people and those with irritable bowel syndrome. They may also influence peptide YY (PYY)–a hormone that can slow intestinal transit–potentially keeping food in the gut longer.9
Cardiovascular Issues (CVD)
Some studies have found that higher overall intake of artificial sweeteners is associated with a greater risk of cardiovascular and cerebrovascular disease. In these findings, aspartame was linked with a higher risk of cerebrovascular events, while acesulfame potassium and sucralose were associated with a higher risk of coronary heart disease.10
Reviews and meta-analyses have also reported a link between artificially sweetened beverages and higher cardiovascular disease (CVD) risk.11 12
In another study, soda intake–especially diet soda–was associated with larger left atrial size and greater left ventricular mass compared with people who didn’t drink soda.13
Neurological Issues
A 2018 review by Choudhary and Lee in Nutritional Neuroscience discusses how aspartame has been implicated in triggering headaches and other neuropsychological symptoms, such as seizures, anxiety, depression, and insomnia. The review notes that aspartame consumption can increase brain levels of phenylalanine and aspartic acid, which may inhibit the synthesis and release of neurotransmitters like dopamine, norepinephrine, and serotonin. Additionally, the authors highlight that aspartame can promote the production of excessive free radicals and elevate cortisol levels, increasing the brain’s susceptibility to oxidative stress and potentially harming neurobehavioral health.14
A decrease in serotonin levels is believed to induce vasodilation, which is hypothesized to be the underlying mechanism responsible for the manifestation of migraine pain. A 1988 study suggests that dietary intake of phenylalanine, an amino acid present in aspartame, may influence brain function and could potentially trigger or exacerbate migraine headaches in susceptible individuals.15
Artificial sweeteners may also reduce your sensitivity to sweet flavors by affecting the amygdala and insula.16 17
Diabetes
A 2022 study found that artificial sweetener intake increased the incidence of diabetes. The artificial sweeteners included: total sweeteners, aspartame, acesulfame-K, and sucralose.18
A meta-analysis found links between artificial sweeteners and Type 2 Diabetes risk.19
Another study confirmed similar results in reporting a direct link between artificial sweeteners and Type 2 Diabetes,20 further supported by a 2022 World Health Organization study.21
Allergic Reactions
Artificial sweeteners have been associated with allergic reactions, including aspartame, xylitol, and erythritol. When aspartame breaks down into formaldehyde, it may be a factor in systemic reactions such as skin rashes and contact dermatitis.22 23
Erythritol has also been linked to urticarial reactions, including symptoms such as hives and rashes.24
Xylitol has been associated with severe allergies, such as skin symptoms and oral ulcers.25
Healthier Sugar Alternatives
Better choices to use as sweeteners in moderation include: raw honey, black molasses, monk fruit, dates, and fruit purees. Allulose is a sugar found naturally in foods like figs, raisins, and maple syrup. You eliminate allulose through urine, so it is not digested and absorbed as calories.26
Stevia is a safe, natural, zero-calorie sweetener that does not spike blood sugar levels.
Erythritol is a sugar alcohol that’s made from a commercial fermentation process. It’s also mostly excreted in urine, so it does not contribute meaningful calories or sugar to the diet. It has a low-impact effect on blood sugar.27
Supplements to Consider
Dr. Grossman’s Complete Eye (oral Spray)/Meso Plus Combo
Dr. Grossman’s Complete Eye Formula 2oz (oral spray)
Dr. Grossman’s Meso Plus Formula with Astaxanthin – 90 vcaps (3-month supply)
Dr. Grossman’s Circulation and Optic Nerve Support Formula
Dr. Grossman’s Bilberry/Ginkgo Combination 2oz (60ml) – helps strengthen blood vessels and capillaries, and support healthy circulation
Retinal Support (wild-crafted herbal formula) 2 oz – based on classic Chinese Liver tonic. In Chinese medicine, the Liver “opens to the eyes”, so is the primary meridian (flow of energy) to support the free flow of circulation and energy throughout the eyes (and body as well).
Dr. Grossman’s Whole Food Organic Superfood Multi-Vitamin 120 Vcaps – our whole food, organic, GMO-free formula
H2 Elite Molecular Hydrogen 60 tabs
Cognirev Extra Strength 2 oz Oral Spray
Recommended Books
Natural Eye Care: Your Guide to Healthy Vision and Healing
Natural Parkinson’s Support (ebook): Your Guide to Preventing and Managing Parkinson’s
- Liu L, Zhang P, Wang Y, Cui W, Li D. “The relationship between the use of artificial sweeteners and cancer: a meta-analysis of case-control studies.” Food Sci Nutr. 2021;9:4589-4597. doi:10.1002/fsn3.2395. ↩
- Weihrauch MR, Diehl V. “Artificial sweeteners–do they bear a carcinogenic risk?” Ann Oncol. 2004;15:1460-1465. doi:10.1093/annonc/mdh256. ↩
- Ruiz-Ojeda FJ, Plaza-Diaz J, Saez-Lara MJ, Gil A. “Effects of sweeteners on the gut microbiota: a review of experimental studies and clinical trials.” Adv Nutr. 2019;10:0-48. doi:10.1093/advances/nmy037. ↩
- “Neurology.” 2025 Oct 7;105(7):e214023. doi:10.1212/WNL.0000000000214023. Epub 2025 Sep 3. ↩
- “Clin Exp Ophthalmol.” 2018;46:767-776. ↩
- Suez J, Korem T, Zeevi D, Zilberman-Schapira G, Thaiss CA, Maza O, Israeli D, Zmora N, Gilad S, Weinberger A, Kuperman Y, Harmelin A, Kolodkin-Gal I, Shapiro H, Halpern Z, Segal E, Elinav E. “Artificial sweeteners induce glucose intolerance by altering the gut microbiota.” Nature. 2014 Oct 9;514(7521):181-186. doi:10.1038/nature13793. Epub 2014 Sep 17. PMID:25231862. https://pubmed.ncbi.nlm.nih.gov/25231862/ ↩
- Spencer M, Gupta A, Dam LV, Shannon C, Menees S, Chey WD. “Artificial Sweeteners: A Systematic Review and Primer for Gastroenterologists.” J Neurogastroenterol Motil. 2016 Apr 30;22(2):168-180. doi:10.5056/jnm15206. PMID:26932837; PMCID:PMC4819855. https://pmc.ncbi.nlm.nih.gov/articles/PMC4819855/ ↩
- Lawrie CA, Renwick AG, Sims J. “The urinary excretion of bacterial amino-acid metabolites by rats fed saccharin in the diet.” Food Chem Toxicol. 1985;23:445-450. doi:10.1016/0278-6915(85)90138-3. ↩
- Hellstrom PM, Naslund E, Edholm T, et al. “GLP-1 suppresses gastrointestinal motility and inhibits the migrating motor complex in healthy subjects and patients with irritable bowel syndrome.” Neurogastroenterol Motil. 2008;20:649-659. doi:10.1111/j.1365-2982.2007.01079.x. ↩
- Chazelas E, Debras C, Srour B, et al. “Sugary drinks, artificially-sweetened beverages, and cardiovascular disease in the NutriNet-Sante cohort.” J Am Coll Cardiol. 2020;76:2175-2177. doi:10.1016/j.jacc.2020.08.075. ↩
- Meng Y, Li S, Khan J, et al. “Sugar- and artificially sweetened beverages consumption linked to type 2 diabetes, cardiovascular diseases, and all-cause mortality: a systematic review and dose-response meta-analysis of prospective cohort studies.” Nutrients. 2021;13:2636. doi:10.3390/nu13082636. ↩
- Yin J, Zhu Y, Malik V, et al. “Intake of sugar-sweetened and low-calorie sweetened beverages and risk of cardiovascular disease: a meta-analysis and systematic review.” Adv Nutr. 2021;12:89-101. doi:10.1093/advances/nmaa084. ↩
- Andersson C, Sullivan L, Benjamin EJ, Aragam J, Jacques P, Cheng S, Vasan RS. “Association of soda consumption with subclinical cardiac remodeling in the Framingham heart study.” Metabolism. 2015;64:208-212. doi:10.1016/j.metabol.2014.10.009. ↩
- Choudhary AK, Lee YY. “Neurophysiological symptoms and aspartame: what is the connection?” Nutr Neurosci. 2018;21:306-316. doi:10.1080/1028415X.2017.1288340. ↩
- Koehler SM. “Dietary Phenylalanine and Brain Function.” Boston, MA: Birkhauser Boston; 1988. “The effect of aspartame consumption on migraine headache: contribute to preliminary results.” pp. 313-316. ↩
- Rudenga KJ, Small DM. “Amygdala response to sucrose consumption is inversely related to artificial sweetener use.” Appetite. 2012;58:504-507. doi:10.1016/j.appet.2011.12.001. ↩
- Burke MV, Small DM. “Physiological mechanisms by which non-nutritive sweeteners may impact body weight and metabolism.” Physiol Behav. 2015;152:381-388. doi:10.1016/j.physbeh.2015.05.036. ↩
- Debras C, Chazelas E, Srour B, et al. “Artificial sweeteners and cancer risk: results from the NutriNet-Sante population-based cohort study.” PLoS Med. 2022;19:0. doi:10.1371/journal.pmed.1003950. ↩
- 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;189:0-39. doi:10.1503/cmaj.161390. ↩
- Qin P, Li Q, Zhao Y, et al. “Sugar and artificially sweetened beverages and risk of obesity, type 2 diabetes mellitus, hypertension, and all-cause mortality: a dose-response meta-analysis of prospective cohort studies.” Eur J Epidemiol. 2020;35:655-671. doi:10.1007/s10654-020-00655-y. ↩
- Rios-Leyvraz M, Montez J. “Health Effects of the Use of Non-sugar Sweeteners: A Systematic Review and Meta-Analysis.” Geneva: World Health Organization; 2022. ↩
- Hill AM, Belsito DV. “Systemic contact dermatitis of the eyelids caused by formaldehyde derived from aspartame?” Contact Dermatitis. 2003;49:258-259. doi:10.1111/j.0105-1873.2003.0225a.x. ↩
- Bradstock MK, Serdula MK, Marks JS, Barnard RJ, Crane NT, Remington PL, Trowbridge FL. “Evaluation of reactions to food additives: the aspartame experience.” Am J Clin Nutr. 1986;43:464-469. doi:10.1093/ajcn/43.3.464. ↩
- Hino H, Kasai S, Hattori N, Kenjo K. “A case of allergic urticaria caused by erythritol.” J Dermatol. 2000;27:163-165. doi:10.1111/j.1346-8138.2000.tb02143.x. ↩
- Hanakawa Y, Hanakawa Y, Tohyama M, Yamasaki K, Hashimoto K. “Xylitol as a causative agent of oral erosive eczema.” Br J Dermatol. 2005;152:821-822. doi:10.1111/j.1365-2133.2005.06526.x. ↩
- Tani Y, Tokuda M, Nishimoto N, Yokoi H, Izumori K. “Allulose for the attenuation of postprandial blood glucose levels in healthy humans: A systematic review and meta-analysis.” PLoS One. 2023;18(4):e0281150. doi:10.1371/journal.pone.0281150. ↩
- Mazi TA, Stanhope KL. “Erythritol: An In-Depth Discussion of Its Potential to Be a Beneficial Dietary Component.” Nutrients. 2023;15(1):204. doi:10.3390/nu15010204. ↩
