Is diet soda healthier than regular soda? Is it better to use artificial sweeteners in coffee than regular sugar? What about stevia or other naturally-derived sweeteners, are these better options?
With growing awareness that too much added sugar can contribute to tooth decay, diabetes, heart disease, unintentional weight gain, and other health issues, many people are seeking low- or no-added-sugar sweetener alternatives. Sugar-free sweeteners, often referred to as “non-nutritive sweeteners” or “low-calorie sugar substitutes,” contribute zero or few calories since the body cannot digest, absorb, and then use them as energy, and they don’t tend to directly raise blood sugars as much as sugar does. They include chemically-derived artificial sweeteners and plant-derived natural sweeteners like stevia and monk fruit. Most are 200-700 times sweeter than table sugar so only a small amount is needed; though the high-intensity and sometimes metallic or bitter flavors turn many people off.
While the use of artificial sweeteners is widespread and considered safe by the FDA, their healthfulness has been hotly debated.
Sugar alcohols like xylitol, sorbitol, erythritol, and mannitol, commonly found in candies, gum, and toothpaste, make another category since they contain some calories (about 2 calories per gram or half the calories in sugar). Their carbohydrates are not digested in the same way as sugar so are not categorized as “added sugars.”
Natural sweeteners like maple syrup and honey are different, considered to be “added sugars” because they have substantial amounts of carbohydrates and calories; though they may appeal to those looking for locally-sourced and less-processed sweeteners.
Artificial sweeteners are the most widely-used type of low-calorie sweetener. They are found in many beverages like diet sodas and sports drinks, and foods like frozen desserts, pudding, yogurt, candy, breakfast cereals, and baked goods. The U.S. Food and Drug Administration (FDA) has approved six artificial sweeteners as safe food additives, including sucralose (Splenda®), saccharin (Sweet and Low®), aspartame (Nutrasweet®, Equal®), acesulfame potassium or ace-K (Sunett®, Sweet One®), neotame (Newtame®), and advantame. The FDA has set safety levels for the number of packets considered safe for each type, the upper limit being 23 packets per day for some, and a higher limit for others.
While the use of artificial sweeteners is widespread and considered safe by the FDA, their healthfulness has been hotly debated. Some research studies suggest that artificially-sweetened beverages can support weight control, but others show no effect or even weight gain. While artificial sweeteners contribute few or no calories, they can increase appetite and cravings for sweet foods, and can perpetuate habits of eating ultra-processed foods. Studies also suggest that artificial sweeteners might change the gut microbiome of healthy bacteria and lead to disruptions in regulating blood sugar. Some people also experience digestive issues like diarrhea and bloating. In 2023, the World Health Organization released a new guideline (based on a review of 283 studies) recommending against the use of non-sugar sweeteners to control body weight or reduce noncommunicable disease, and stating the potential increased risks of type 2 diabetes and cardiovascular disease with long-term use.
Links between artificial sweeteners and cancer have also been debated. In July, 2023, the International Agency for Research on Cancer released a statement labeling aspartame as “possibly carcinogenic to humans.” However, the FDA refuted this claim, citing shortcomings in the studies and affirming no safety concerns when aspartame is used within safety levels of consuming <40mg/kg body weight per day—this translates to the safe consumption of up to about eleven 12-oz cans of diet soda a day for a person weighing 150 lbs (68 kg).
Naturally occurring low-calorie sweeteners like stevia and monk fruit have gained popularity as less risky options due to their plant origins, antioxidant qualities, and historical usage. They are often found in sweetened “health food” products such as protein bars and shakes. Stevia is a perennial herb, Stevia rebaudiana, from South America with sweet tasting compounds in the leaves called steviol glycosides—Rebaudioside A (Reb A) and Stevioside being the most common. Truvia®, PureVia®, and Enliten® are sweetener brands containing stevia. Monk fruit, Siraitia grosvenorii, also known as “swingle fruit” and “luo han guo,” has origins in Asia and has been used for centuries in Chinese medicine. Monk fruit gets its sweetness from compounds called mogrosides extracted from the juice of the fruit. Lakanto®, Nectresse®, Monk Fruit in the Raw®, and PureLo® are some brands with monk fruit. Both stevia and monk fruit are labeled generally recognized as safe (GRAS) by scientific and regulatory agencies. Research suggests that these sweeteners have antioxidant, anti-inflammatory, and other beneficial properties, but more research is needed to fully understand benefits and risks.
Allulose is a newer low-calorie sweetener with GRAS status that is gaining popularity. It is derived from a natural sugar found in small quantities in certain fruits. Allulose is 70% as sweet as table sugar and has a good reputation for flavor being similar to table sugar without bitter or chemical notes found in artificial sweeteners, but at a cost 5-7 times more expensive. Recent studies have shown its favorable influences on metabolism and health, but more research is needed.
In addition to differences in flavors, different brands of low-calorie sweeteners have different substitution ratios in place of sugar in recipes and have different cooking properties. For example, allulose, neotame, and erythritol are better for baking than aspartame, which loses sweetness in high heat. Many commercial sweeteners are a mix of natural and artificial sweeteners and fillers, so read the ingredient labels to make an informed choice.
Overall, research is not definitive about the benefits and harms of low-calorie sweeteners. They can be an option for reducing added sugars and calories in the diet, but may not be helpful if depriving sugar provokes unhelpful eating habits. If you can’t let go of soda in your life, diet soda may be a useful temporary replacement. But it would be better to skip the soda, energy drinks, and sweet teas altogether. If you must sweeten your coffee, a natural sweetener like monk fruit may be better for blood sugar control compared to sugar and may be a safer long-term option than artificial sweeteners, but is more expensive and harder to find on the shelves.
