UNDERSTANDING ARTIFICIAL SWEETENERS

Artificial sweeteners. The name alone is enough to make some people worry. These compounds, also referred to as sugar substitutes, were introduced in the 1950s as alternatives to sucrose (regular old sugar) to reduce caloric intake. Since their introduction, there has been a growing curiosity around the impact these sugar substitutes have on the body.  With a plethora of misinformation disseminating across the internet on all topics, I figured a quick guide to understanding artificial sweeteners would be a good thing to have. Before we can get into more complex conversations on artificial sweeteners and address things like: 

"Do artificial sweeteners give you cancer?" 

"Do they mess with your gut microbiome?" 

"Do they make you gain more weight?"

We need to first understand what they are. Most people are ignorant to what these compounds are but have filled their heads with fear about cancer and seizures and tons of other commonly stated and misrepresented facts. So let's start there. Here's a brief look at artificial sweeteners.

You have two main categories: sweeteners and sugar alcohols. Sweeteners (top image) are glycosides and sugar alcohols (bottom image) are alcohols. You can see they are, structurally, very different.

The main artificial sweeteners are:

1. Aspartame (nutrasweet)
2. Stevioside (Steviol)
3. Cyclamate (Sugar twin)
4. Sucralose (Splenda)
5. Acesulfame-Potassium (Sweet One)

There are three main components when determining which artificial sweeteners and/or sugar alcohols to consider: sweetness relative to sucrose, absorption, and metabolism. Absorption: where is it absorbed, how much is absorbed? Metabolism: is it broken down? Where does it get broken down? What does it breakdown into? We will address all three of these components for each of the sugar substitutes starting with sweeteners.

Sweeteners

Aspartame (Nutrasweet) 

• 200x sweeter than sugar
• Metabolized in GI tract, produces:
• • Phenylalanine
  • Methanol
• Products are absorbed in GI tract

Stevioside (Stevia)

• 300x sweeter than sugar
• Not absorbed
• Not metabolized

Cyclamate (Sugar Twin)

• 50x sweeter than sucrose
• Partially absorbed
• Not metabolized

Sucralose (Splenda)

• 600x sweeter than sucrose
• Most not absorbed
• Not metabolized

Acesulfame-Potassium (Sweet One)

• 200x sweeter than sucrose
• Absorbed in GI tract
• Can metabolized to acetoacetamide

Sugar Alcohols (naturally occurring)

Moving onto the the sugar alcohols. And yes, these are ~natural~ so they have to be healthy... Right? Sure. These sugar alcohols differ mostly in the length of their carbon chains. All that means is how many carbon molecules they have.

Sorbitol

• Half as sweet as sucrose
• Low absorption in GI
• Metabolized to fructose
• Hyperosmotic (laxative effect)

Xylitol

• Similar to sucrose in sweetness
• Low absorption in GI
• Metabolized and processed in the pentose phosphate pathway

Erythritol (Truvia)

• Half as sweet as sucrose
• Significantly less calories than sorbitol and xylitol
• Absorbed but not metabolized

Discussion

We won't get into the myths surrounding these compounds as this was just a short and sweet (no pun intended) intro to artificial sweeteners. A couple take aways from this: 

1. Impact: For those worried about these compounds, opt for the ones that are not metabolized or absorbed, at that point they're just eliciting a sweet flavor and passing through. 
2. Taste: For those who don't like the taste, opt for the ones that are less sweet as they have a less prominent taste.
3. Experiment: You might find that certain sweeteners upset your stomach, give you a headache, etc. Everybody is different and reacts differently based on the sweetener so do some research for yourself.

At least now if artificial sweeteners ever come up in conversation, you can rest assured knowing that you know WHAT is being discussed. Oh, and I'll give you a sneak peak from the next paper on these: none of them actually give you cancer... we think.

References:

Artificial sweeteners. (2016). Meyler’s Side Effects of Drugs, 713–716. doi:10.1016/b978-0-444-53717-1.00330-9 

Basson AR, Rodriguez-Palacios A, Cominelli F. Artificial Sweeteners: History and New Concepts on Inflammation. Front Nutr. 2021 Sep 24;8:746247. doi: 10.3389/fnut.2021.746247. PMID: 34631773; PMCID: PMC8497813.

Schiffman, S. S., & Gatlin, C. A. (1993). Sweeteners: State of knowledge review. Neuroscience & Biobehavioral Reviews, 17(3), 313–345. doi:10.1016/s0149-7634(05)80015-6**