Artificial sweeteners are food products in the form of small chemicals that are used to make foods taste sweet without adding calories. These food products are often scrutinized in popular media. This NutriWiki will cover the most up to date science on artificial sweeteners.
- Artificial sweeteners are generally safe. They are only toxic at levels much higher than what the average person consumes.
- Aspartame should not be consumed by people with phenylketonuria (an uncommon genetic disorder).
- Artificial sweeteners cannot cause fat gain. However, they can cause people to eat more, which can cause fat gain.
Artificial sweeteners, such as the ones found in diet sodas and low calorie foods, have a poor reputation. In particular, aspartame is often singled out as the “poisonous” substance when people think of “dangerous sweeteners.” Despite the scary reputation, most studies indicate aspartame, as well as artificial sweeteners in general, are safe for consumption.
For the sake of brevity, this discussion will focus on aspartame, but these statements can be extrapolated to other artificial sweeteners in general.
The studies finding adverse effects tend to fall into one of two categories:
Observational: These are studies which observe populations of people over time, and draw conclusions based on trends and relationships. These studies cannot determine that one thing causes another, only that the two might be associated.
Dose-dependent: These studies feed different groups different amounts of a substance, and observe them for effects. Most of these are done with rodents, and the dosages given usually are much higher than the intakes seen in humans.
Outside of these scenarios, there is no solid evidence that artificial sweeteners are harmful to humans. They also have no negative effects on blood glucose, insulin, or other blood markers1, and have been cleared by many regulatory agencies worldwide2.
The acceptable daily intake (ADI) for aspartame is 50 mg/kg/bodyweight3, which is an intake significantly higher than the average person consumes. For example, an approximately 135 pound (60 kg) adult would have an ADI of 3,000 mg of aspartame. Since the average can of diet soda has around 180 mg, said person could consume almost seventeen cans of diet soda and remain within this limit.
Even if that limit was exceeded, it would still likely be safe. The no-observed-actual-effect level (NOAEL) of aspartame is much higher, at 4,000 mg/kg/bodyweight4. Using the same hypothetical person, that calculates to over 1,300 cans of diet soda.
One notable exception is in people diagnosed with phenylketonuria (PKU). PKU is a genetic disorder in which individuals cannot metabolize the essential amino acid phenylalanine effectively, causing it to build up to toxic levels in the body5. Since aspartame metabolism produces phenylalanine, people with PKU are advised to avoid it.
Although artificial sweeteners taste very sweet, they have very low to no caloric content. Therefore, they cannot directly contribute to weight gain. However, people may compensate for this by increasing their accompanying food intake, with the mental justification that they’re cutting calories with the diet drink. This compensation can hinder fat loss or even cause fat gain if the caloric intake is high enough.
- Santos NC, de Araujo LM, De Luca Canto G, Guerra ENS, Coelho MS, Borin MF. Metabolic effects of aspartame in adulthood: A systematic review and meta-analysis of randomized clinical trials. Crit Rev Food Sci Nutr. 2018;58(12):2068-2081. doi: 10.1080/10408398.2017.1304358. Epub 2017 Aug 18.
- Butchko HH, Stargel WW, Comer CP, Mayhew DA, Benninger C, Blackburn GL, et al. (April 2002). “Aspartame: review of safety”. Regulatory Toxicology and Pharmacology. 35 (2 Pt 2): S1–93. doi:10.1006/rtph.2002.1542. PMID12180494
- Additional information about High-Intensity Sweeteners Permitted for Use in Food in the United States. Food and Drug Administration website. https://www.fda.gov/food/food-additives-petitions/additional-information-about-high-intensity-sweeteners-permitted-use-food-united-states. Accessed November 24, 2019.
- EFSA ANS Panel (EFSA Panel on Food Additives and Nutrient Sources added to Food), 2013. Scientific Opinion on the re-evaluation of aspartame (E 951) as a food additive. EFSA Journal 2013;11(12):3496, 263 pp. doi:10.2903/j.efsa.2013.3496.
- “phenylketonuria”. Genetics Home Reference. September 8, 2016. Retrieved 24 November 2019.