Artificial Sweeteners—Are they a Healthy Choice?
Researchers, clinicians, and cardiologists have established that obesity is a major risk factor in the development of cardiovascular disease, diabetes, and other chronic disease processes. The cycle of sweetness and obesity may be extremely difficult to break because of the apparent addictiveness of sugar. Researchers have even equated the addictiveness of sweets to that of cocaine in rats! Experimental data indicating dopamine signaling in the ventral striatum, the area of the brain involved in reward processing and learning, is stimulated with the ingestion of sweets or with drugs of abuse (Lenoir, Serre, Cantin, & Ahmed, 2007).(1)
Dietary counseling, regular exercise and appropriate weight loss strategies are paramount in health care management of obesity-related medical conditions. Reducing caloric intake is a large part of this counseling, leading to the use of artificial sweeteners. Artificial sweeteners offer sweetness without the use of sugar (sucrose) and the calories, making use of them seem like a useful approach.
Some research has associated artificial sweeteners with health conditions such as cancers, hepatotoxicity, migraines, and low birth weight. Aspartame, marketed as Equal, Nutrasweet, Equal Measure, Spoonful, and Canderal, was FDA approved for use in dry foods in 1981, after previous refusals due to evidence this drug produced seizures and brain tumors in lab animals. In 1996 the FDA reclassified aspartame as safe for use as a food additive without restrictions. The FDA calls aspartame, “one of the most thoroughly tested and studied food additives the agency has ever approved.” Aspartame is found in such popular products as Diet Coke, Diet Pepsi, Diet Snapple and Sugar Free Kool-Aid. Hundreds of millions of people consume it worldwide.
Controversy has swirled around this prolific food additive. Health advocates have railed against the additive claiming it is carcinogenic (cancer-causing) and the source of over 90 reported health effects. Loosely associated multiple neurological, gastrointestinal, cardiovascular, and respiratory symptoms have been reported to the Department of Health and Human Services. Aspartame accounted for more than 75% of all adverse reactions voluntarily reported to the FDA's Adverse Reaction Monitoring System (ARMS). The sweetener industry has vigorously defended the safety record of aspartame and cites multiple studies as evidence of its safety.
The controversy centers on the chemical make-up of aspartame and its metabolic breakdown products phenylalanine, aspartic acid and methanol. Absorption of methanol is sped up considerably when free methanol is ingested. Free methanol is created from aspartame when heated above 86° Fahrenheit. This occurs when an aspartame-containing product is improperly stored or heated (e.g., as part of a product such as Jello). Methanol is broken down into formic acid and formaldehyde, a deadly neurotoxin. An EPA assessment of methanol notes it "is considered a cumulative poison due to the low rate of excretion once absorbed.” The controversy surrounding aspartame questions whether enough methanol is present in order to cause health risks.
A study published in March 2006 by the Cesare Maltoni Cancer Research Center of the European Ramazzini Foundation may help to clarify facts about aspartame. The Center conducted a 7-year, million dollar study on aspartame. The researchers reported the sweetener was associated with unusually high rates of lymphomas, leukemias and other cancers in rats given doses starting at what would be equivalent to four to five 20-ounce bottles of diet soda a day for a 150-pound person. This study may compel further review of this highly controversial food additive.(2)
Imposing restrictions on aspartame would come at a significant cost. Consumers around the world bought about $570 million worth of the chemical in food products several years ago. New regulatory action would jeopardize billions of dollars of products containing aspartame.
Other artificial sweeteners have also been fraught with controversy. Saccharin, available under trade names such as Sweet 'n Low, is used widely in fountain sodas. Unlike aspartame, which degrades when heated, its stability at high temperatures makes saccharin an option for sweetening baked goods. But should consumers use it? "We know for certain that it causes cancer in animals," says Andrew Laumbach, Ph.D., consumer safety officer in FDA's Office of Premarket Approval. He acknowledges, however, that animal studies do not always predict the behavior of substances in the human body.(3)
Stevia, currently marked as “Truvia,” is an inexpensive herb from Africa, imparts a sweet taste to foods, but cannot be sold as a sweetener since it’s considered an unapproved food additive by FDA. High-purity stevia glycoside extracts have been generally recognized as safe (GRAS) since 2008, and are allowed in food products, but stevia leaf and crude extracts do not have GRAS or Food and Drug Administration (FDA) approval for use in food. "The safety of stevia has been questioned by published studies," says Martha Peiperl, a consumer safety officer in FDA's Office of Premarket Approval. "And no one has ever provided FDA with adequate evidence the substance is safe." When a journalist asked the agency in 1997 for a list "of all studies the FDA is aware of alleging a detrimental effect from stevia or steviosides," it cited 19 studies. (FDA officials would not confirm if the "studies" mentioned had been reviewed, some of which were brief reports and one a letter to the editor of a foreign journal).
Other natural sweeteners, including honey, molasses, evaporated cane juice, rice syrup, barley malt, and fructose, contain about the same amount of calories as refined table sugar. Unrefined sugars contain trace minerals, natural flavor and coloring, are approximately 60% as sweet as refined sugar, and raise blood sugar more slowly than refined sugar.
Microbiome Effects
Intestinal microbial communities (AKA friendly “gut bugs” or “normal flora”) regulate a range of host physiological functions, from energy harvest and glucose regulation to immune development and regulation. Disruptions in the normal intestinal flora can lead to yeast infections, urinary tract infections, intestinal distress (gas, bloating, diarrhea or constipation) increased allergy incidence, and we are beginning to understand a “gut-brain” connection causing depression, anxiety, cravings, etc. Notably for this article, we are seeing evidence that microbiome disruptions can also lead to metabolic syndrome, insulin resistance, and obesity.
In spite of industry claims, lowering caloric intake and combating obesity may not be best accomplished using artificial sweeteners. The potential health risks appear to outweigh the benefits. In fact, it appears use of artificial sweeteners actually increases the incidence of metabolic syndrome, obesity, and diabetes.(4) One of the suspected mechanisms of the metabolic changes is disruptions of the microbiome.(5) In short, the bacteria that are helpful and supposed to populate our gut eat plant-based sugars and fiber. When artificial sweeteners are utilized, the balance and diversity of the microbiome is disrupted. Fecal transplant studies whereby intestinal microbes from artificial sweetener-consuming hosts are transferred into germ-free mice, show that this disruption is transferable and results in impaired glucose tolerance.
Suez, J., Korem, T., Zeevi, D. et al. demonstrated that consumption of commonly used artificial sweetener formulations drives the development of glucose intolerance through disruption of the intestinal microbiome make-up and the functions the normal microbiome perform. These artificial sweetener-mediated disruptions to the normal metabolic activities of the intestinal microbiome were eliminated by antibiotic treatment, suggesting the microbes that flourished during artificial sweetener ingestion were the cause of the metabolic disruptions. Furthermore, these metabolic disruptions were observed to be fully transferrable to germ-free mice upon fecal transplantation of microbiota from artificial sweetener-consuming mice. This effect was also observed from microbiota anaerobically incubated in the presence of artificial sweeteners (not in a host), eliminating the possibility these metabolic disruptions were somehow transferred from the sickened mice to the healthy ones. They were able to link artificial sweetener consumption, dysbiosis and metabolic abnormalities and demonstrate similar artificial sweetener-induced dysbiosis and glucose intolerance in healthy human subjects. (6)
Accurate and thorough dietary counseling remains the foundation of health care management. Use natural unrefined sweeteners in moderation, increase fiber intake with fruits and vegetables, and reduce processed fat and refined carbohydrate intake. Increase caloric metabolism by increasing daily exercise. Laugh, love, and live!
- Lenoir, M., Serre, F., Cantin, L., & Ahmed, S. H. (2007). Intense sweet-ness surpasses cocaine reward. Retrieved February 16, 2008, from www.pubmedcentral.nih.gov/picrender.fcgi?artid=1931610&blobtype=pdf
- Environ Health Perspect. 2006 Mar;114(3):379-85. First experimental demonstration of the multipotential carcinogenic effects of aspartame administered in the feed to Sprague-Dawley rats. Soffritti M1, Belpoggi F, Degli Esposti D, Lambertini L, Tibaldi E, Rigano A.
- Andrew Laumbach, Ph.D., consumer safety officer in FDA's Office of Premarket Approval. FDA Consumer, November-December 1999, Volume 33, page 14
- Nutrition and Obesity (S McClave and J Obert, Section Editors) Published: 21 November 2017.The Association Between Artificial Sweeteners and Obesity. Michelle Pearlman, Jon Obert & Lisa Casey
- Physiology & Behavior, Volume 164, Part B, 1 October 2016, Pages 488-493. Reshaping the gut microbiota: Impact of low calorie sweeteners and the link to insulin resistance? Jodi E.Nettletona, Raylene A.Reimer, Jane Shearer
- Suez, J., Korem, T., Zeevi, D. et al. Artificial sweeteners induce glucose intolerance by altering the gut microbiota. Nature 514, 181–186 (2014). https://doi.org/10.1038/nature13793