Sugar substitutes are substances used instead of sugar to add sweetness to food and beverages. Their popularity is driven by the desire to reduce caloric intake. Both artificial and natural sweeteners allow people to enjoy a sweet taste without extra calories, making them especially attractive for individuals managing their weight, following a diet, or maintaining energy balance.
Additionally, sugar substitutes help regulate blood glucose levels. Diabetics often use them to prevent sharp blood sugar spikes caused by regular sucrose consumption. Some sweeteners have little to no impact on insulin response, making them a convenient alternative for managing metabolic processes.
However, the popularity of sugar substitutes is influenced not only by their composition but also by marketing. Manufacturers frequently use terms such as “natural,” “healthy,” and “sugar-free” to create the impression that these products are always safe. However, scientific research provides mixed results. Artificial sweeteners do not always aid in weight loss, and some may disrupt gut microbiota, alter insulin levels, and even increase the risk of chronic diseases, including cancer.
Differences Between Natural and Artificial Sugar Substitutes
Sugar substitutes fall into two main categories: natural and artificial. The key differences between them are their origin, caloric value, and impact on the body.
Natural sugar substitutes are derived from natural sources such as plants and fruits. They are generally considered safer, have a lower glycemic effect compared to sugar, and sometimes offer additional health benefits. However, some can have a laxative effect when consumed in large quantities.
- Xylitol (E967) – sweetness 0.7–1.0 of sugar, protects tooth enamel but is toxic to dogs.
- Sorbitol (E420) – sweetness 0.6 of sugar, commonly used in chewing gum but can cause gastrointestinal issues in large doses.
- Maltitol (E965) – sweetness 0.7–0.9 of sugar, partially absorbed by the body, which may raise blood sugar levels.
- Erythritol (E968) – sweetness 0.6–0.8 of sugar, not absorbed, does not raise blood sugar, and is calorie-free.
- Stevia (E960) – sweetness 150–300 of sugar, contains no calories but may cause allergic reactions and contains oxalates.
Artificial sugar substitutes are chemically synthesized and typically have an extremely high level of sweetness without calories. They are widely used in the food industry, but their long-term health effects remain a topic of study.
- Aspartame (E951) – sweetness 200 times that of sugar, the most common sweetener but controversial in terms of safety.
- Sucralose (E955) – sweetness 600 times that of sugar, heat-stable but may affect gut microbiota.
- Saccharin (E954) – sweetness 300–500 times that of sugar, the oldest sweetener, with some users reporting side effects.
- Acesulfame-K (E950) – sweetness 200 times that of sugar, heat-stable but requires limited consumption.
Additional data on the effects of sugar substitutes on blood sugar, insulin levels, and weight management are presented below.
What Sugar Substitutes Risks Have Been Recognized by WHO and Which Are Still Under Investigation?
Some sugar substitutes are approved for consumption, but that does not mean they are entirely safe. The WHO evaluates sugar substitutes based on long-term risks such as cancer and metabolic disorders. However, research is ongoing, and several effects have not yet been included in official recommendations.
Aspartame
- Classified by the WHO in 2023 as “possibly carcinogenic” (Group 2B) but considered safe within approved doses.
- An ingredient in Diet Coke, Coca-Cola Zero Sugar, Pepsi Max.
- Potential side effects (under investigation):
- Cognitive impairment – possible effects on neurotransmitters, increased anxiety, and memory deterioration.
- Association with migraines – chronic headache sufferers often report worsened symptoms.
- Impact on serotonin levels – high doses may contribute to depression.
Sucralose
- Approved by the WHO but recommended for limited consumption.
- Potential side effects:
- Gut microbiome disruption – reduces beneficial bacteria in the intestines.
- Formation of toxic compounds when heated – possible effects on liver health and DNA integrity.
- Influence on glucose metabolism – may increase the risk of prediabetic conditions.
Acesulfame-K
- Approved by the WHO, but its long-term effects are still under investigation.
- An ingredient in Diet Coke, Coca-Cola Zero Sugar, Pepsi Max.
- Potential side effects:
- Animal studies have shown possible effects on the thyroid gland.
- May impact cognitive functions, but data is currently limited.
- Some studies suggest a potential link to increased cancer risk, though evidence remains insufficient.
Saccharin
- Once considered a carcinogen, but the WHO later reassessed this risk.
- Potential side effects:
- Microbiome alterations – may disrupt gut flora.
- Metallic aftertaste and digestive issues – reported in some individuals.
Erythritol
- Officially approved by the WHO.
- 2023 studies suggest:
- May increase the risk of thrombosis and cardiovascular diseases.
- Affects vascular responses, potentially raising stroke risk.
Xylitol, Sorbitol, Maltitol (Polyols)
- Recognized as safe but can cause laxative effects when consumed in large amounts.
- Potential side effects:
- Microbiome alterations, especially with long-term use.
- Irritable bowel syndrome (IBS) exacerbation in sensitive individuals.
How Do Sugar Substitutes Affect Blood Sugar, Insulin, and Weight?
Apart from potential health risks, it’s essential to understand how different sugar substitutes influence key metabolic processes.
Natural Sugar Substitutes (Stevia, Monk Fruit)
- Blood sugar levels: Have little to no impact.
- Insulin response and insulin resistance: Do not affect insulin sensitivity.
- Weight management: Calorie-free and may help with weight loss if they do not trigger cravings for sweets.
Natural Sugar Substitutes (Erythritol, Xylitol, Sorbitol)
- Blood sugar levels: Slightly increase blood sugar, but excessive consumption may cause digestive issues.
- Insulin response and insulin resistance: May mildly increase insulin levels due to partial absorption.
- Weight management: Low in calories but can cause laxative effects when overconsumed.
Artificial Sugar Substitutes (Aspartame, Sucralose, Saccharin)
- Blood sugar levels: Do not raise blood sugar, as they are not metabolized by the body.
- Insulin response and insulin resistance: Some studies suggest they may alter gut microbiota and influence insulin sensitivity.
- Weight management: Calorie-free, but may increase cravings for sweets, leading to overeating.
Important! While sugar substitutes were previously believed to aid in weight loss, recent research suggests that some may increase appetite, leading to higher calorie consumption.
Where Are Sugar Substitutes Most Commonly Found?
Sugar substitutes are added to many products, even those that may not seem “diet-friendly” at first glance. They can be found in:
- Diet sodas: Diet Coke, Coca-Cola Zero Sugar, Pepsi Max.
- Protein bars and powders.
- Fat-free yogurts (fat is removed, but sweeteners are added).
- Sugar-free chewing gums and candies.
- Processed sauces, ketchup, mustard.
- Medications and cough syrups.
- Baked goods, bread, and crackers labeled as “low-calorie.”
Important! Sugar substitutes can also be found in children’s products, especially vitamins and syrups.
What Are the Safest Sugar Substitutes and Sweeteners?
The safety of sugar substitutes remains a topic of debate. However, some options are currently considered the most neutral for health. When choosing a sugar substitute, it is important to consider its impact on blood sugar levels, insulin response, and overall health. The best choices for avoiding blood sugar spikes and insulin surges include:
- Berries – Low in sugar and high in fiber, which slows down sugar absorption. The best options include raspberries, blueberries, and blackberries, as they have a low glycemic index.
- Cinnamon and vanilla – Enhance sweetness without containing sugar; cinnamon also improves insulin sensitivity.
- Xylitol – Has minimal impact on blood glucose levels and helps protect tooth enamel by inhibiting bacteria that cause cavities.
- Erythritol – Not absorbed by the body, does not raise blood sugar levels, has no metabolic impact, and does not contribute to cavities.
- Stevia – A natural sweetener with zero calories that does not affect blood sugar or insulin levels, though it has a distinct aftertaste.
Conclusion
Despite the widespread promotion of sugar substitutes as a safe alternative to sugar, research suggests that they may not always be beneficial and could pose new risks.
It was previously believed that sugar substitutes aid in weight loss, but modern data indicate the opposite—they may increase cravings for sweets, leading to overeating.
Ultimately, the best approach is not to seek a sugar replacement but to reduce overall sugar consumption. There are no “miracle” products, and the real issue lies in the habit of excessive sweetness, which should be addressed.
World Health Organization (WHO): Non-Sugar Sweeteners: Questions and Answers
U.S. Food and Drug Administration (FDA): Aspartame and Other Sweeteners in Food
European Food Safety Authority (EFSA): Sweeteners