When ranking common sugar substitutes by safety, stevia is generally considered the safest. It is a natural, plant-derived sweetener with zero calories and is widely recognized as safe for consumption. Most people tolerate it well, with only mild digestive discomfort reported in some cases, and it does not break down into harmful compounds during use.
Unfortunately, healthy things are not profitable, so stevia products are starting to contain unhealthy additives. Most stevia products on the market today are unfortunately are not just pure stevia; they are blends containing fillers like maltodextrin, erythritol, or sucralose—ingredients that bring their own health risks.
Erythritol, a sugar alcohol, also has a generally favorable safety profile due to its minimal effect on blood sugar and low calorie content. However, recent laboratory studies indicate that erythritol may damage the cells lining blood vessels in the brain, which could impair blood flow and potentially increase the risk of ischemic stroke. Furthermore, higher blood levels of erythritol have been associated in population studies with an increased risk of blood clots, heart attack, and stroke. While more research is needed to fully understand these effects in everyday human consumption, these findings raise concerns about erythritol’s impact on cardiovascular health, especially in individuals with preexisting conditions.
Sucralose is approved by regulatory agencies and is generally considered safe. Some studies suggest it may disrupt gut microbiota, potentially leading to digestive issues or metabolic changes over time, but “strong evidence of harm in humans is lacking.” Nevertheless, sucralose is associated with disruptions to gut bacteria and potential inflammatory responses.
Acesulfame potassium (Ace-K) is also deemed safe at typical consumption levels. Animal studies have suggested that very high doses might increase cancer risk and impair thyroid function, but these effects have not been confirmed in humans.
Saccharin, one of the oldest artificial sweeteners, was linked to bladder cancer in rats when given at extremely high doses. However, extensive human studies have not found a similar increased cancer risk, leading authorities to consider saccharin safe within established intake limits.
Maltodextrin is a highly processed carbohydrate that can spike blood sugar and reduce insulin sensitivity, increasing the risk of type 2 diabetes.
Other sugar alcohols such as sorbitol and xylitol generally pose few risks when consumed moderately but can cause gastrointestinal distress, including bloating, diarrhea, and gas, especially at higher intakes. Importantly, xylitol is highly toxic to dogs and should be kept away from pets.
Aspartame is the least safe of the common sweeteners due to its chemical instability when heated. Upon exposure to heat, aspartame breaks down into formaldehyde and methanol, both of which are toxic compounds linked to cellular damage and increased cancer risk. Additionally, aspartame metabolizes into phenylalanine, which can be harmful to individuals with phenylketonuria (PKU), a rare genetic disorder. These factors make aspartame unsuitable for cooking or baking and warrant caution in general use.
In summary, stevia and sugar alcohols like erythritol are among the safest sugar substitutes, though erythritol’s emerging association with cardiovascular risks should be monitored. Artificial sweeteners vary in safety, but aspartame’s toxic breakdown products under heat clearly make it the most concerning option, especially for cooked foods and sensitive populations.