Why I don't hate artificial sweeteners

controversial? I'll let you be the judge of that...

Okay, so I should probably preface my ramblings here with quite a big disclaimer:

This article is purely for fun. Educational, well yes - somewhat, but in a “hey, this chemistry is cool and I think more people should know about it” sorta way. Food additives labelled ‘artificial’ are frequently demonised in the media with little explanation; hence, I believe that greater awareness and understanding of the chemistry of these molecules and how they interact with the body could be beneficial. TL;DR: by no means do I wish to either encourage or discourage the consumption of artificial sweeteners. I simply wish to lay out some interesting facts about them, explain how they work, and then let you come to your own decision about how often you may wish to consume them.

Alright, I think that’s everything.

I shall now stop procrastinating…

---

The sensation of sweetness (artificial or otherwise) is, like many things, all down to chemistry. Our taste buds contain specific receptors that detect sweet compounds—primarily the TAS1R2 and TAS1R3 receptors. When sugar - sucrose, for example -binds to these receptors, it triggers a signal to the brain, resulting in a pleasant perception of sweetness. Artificial sweeteners, though vastly different in structure from sucrose, can mimic this interaction effectively.

image credit: Harvard Health

I’ll start with aspartame…

Aspartame is commonly found in:

1. Diet sodas and other low-calorie beverages

2. Sugar-free gum and sweets (candy, if you’re not from the UK)

3. Low-fat yogurts and other sweetened dairy products

4. Tabletop sweeteners (I think I saw it at Tesco once?)

   

   I did in fact see it at Tesco once. | image credit: Tesco

5. Some medications and vitamins (idk about you but I find the fact that artificial sweeteners are used in medication oddly unsettling)

And just so you know: Aspartame has been extensively studied and is considered safe for consumption by major regulatory agencies, including the FDA, EFSA, and WHO. These organisations have established an Acceptable Daily Intake (ADI) for aspartame, which is well above the typical consumption levels for most people.

However

Despite its approval, some studies and individuals have raised concerns about aspartame:

• Some people report experiencing headaches after consuming aspartame, although scientific evidence is mixed.

• A large-scale population-based cohort study (NutriNet-Santé) found associations between artificial sweetener consumption, including aspartame, and increased cancer risk. However, it's important to note that this study shows correlation, not causation, and more research is needed to confirm these findings.

• Some research suggests that artificial sweeteners, including aspartame, might affect gut bacteria and potentially influence glucose metabolism, but more studies are needed to confirm these effects.

• Individuals with phenylketonuria (PKU) should avoid aspartame, as they cannot metabolize phenylalanine, one of aspartame’s components (as depicted above).

And now to the chemistry…

Aspartame’s structure is fundamentally different from that of sucrose (your everyday granulated sugar). Rather than being a carbohydrate, it’s a dipeptide composed of two amino acids: aspartic acid and phenylalanine, bonded by a peptide linkage. This structure allows aspartame to bind to sweetness receptors in a way that makes it roughly 200 times sweeter than sucrose, meaning you only need a tiny amount to achieve a significant sweet taste.

However, aspartame’s dipeptide bond is sensitive to heat. It breaks down at higher temperatures, losing its sweetness, hence it’s not ideal for baking. Once ingested, aspartame is broken down into its component amino acids and a trace amount of methanol, which our bodies process easily. For perspective, the amount of methanol from aspartame is significantly lower than the natural methanol found in many fruits and vegetables (tomatoes, for example).

For those of you who want the numbers:

What about the methanol? Isn't methanol poisonous? Methanol is present in a lot of fruits and fruit juices, partly in the form of methyl esters, including pectin. In the digestive system, many of these esters are hydrolyzed to release methanol. Your liver is equipped to handle methanol in this kind of quantity--it oxidizes the methanol to formaldehyde and then to formic acid, which is easily handled by the kidneys. The enzymes doing this are alcohol dehydrogenase and aldehyde dehydrogenase. The process is so efficient that you would have a hard time measuring any formaldehyde in your body. This is true whether you get the methanol from a glass of tomato juice (85 mg), apple juice (21 mg), or a can of diet cola (about 20 mg).

In principle, if you consumed thousands of cans of diet soft drink in an hour, you could get methanol poisoning, but the caffeine overdose would kill you first. The lowest reported lethal dose in humans for caffeine is 192 milligrams per kilogram of body weight; for methanol, it's 6422 milligrams per kilogram. A 12 ounce can of Diet Coke has 46 mg of caffeine and could produce 20 mg of methanol, so for a 150 pound adult, it would take 22,000 cans to produce a lethal dose of methanol, and only 300 cans to produce a lethal dose of caffeine.

This was all quoted from this essay by Dr. Eric Walters who happens to also have this legendary website dedicated to all things sweeteners. Isn’t this just glorious?

---

Sucralose

image credit: The Sweetener Book

Sucralose is another popular artificial sweetener, often marketed under the brand name Splenda. Like aspartame, it’s widely used as a sugar substitute in various food and beverage products.

Sucralose is commonly found in:

1. Diet sodas and other low-calorie beverages

2. Baked goods and desserts

3. Canned fruits and sauces

4. Dairy products like yogurt and ice cream

5. Chewing gum and sweets

6. Tabletop sweeteners (Splenda being the most noteable)

While sucralose is generally considered safe for consumption, recent research has raised some concerns about its potential health effects:

• Studies suggest that sucralose may negatively impact gut microbiota and potentially increase susceptibility to inflammatory conditions. Research on mice showed that sucralose consumption exacerbated the severity of colitis, a type of inflammatory bowel disease. This was associated with changes in gut microbiota, disturbances in intestinal barrier function, and activation of inflammatory pathways.

• Some research indicates that sucralose might affect glucose metabolism, although more studies are needed to confirm these effects in humans.

• When used in cooking or baking at high temperatures, sucralose may break down and potentially form harmful compounds. This is an area that requires further investigation.

• Sucralose can participate in browning reactions, particularly when combined with amino acids like lysine. This could affect the colour and potentially the nutritional quality of certain foods.

• Sucralose is highly stable and not easily broken down in the environment, leading to concerns about its accumulation in water systems.

But, as I said, I’m not here to get bogged down in the health (or environmental, in this case) implications; I simply feel as though listing them here is common courtesy. For what would an article on artificial sweeteners be without such?

And now for the good part…

Sucralose starts as sucrose but undergoes a selective chlorination process where three hydroxyl (–OH) groups are replaced by chlorine atoms. This alteration makes sucralose about 600 times sweeter than sugar and non-metabolizable; the chlorine atoms effectively render the molecule resistant to breakdown by digestive enzymes. This means sucralose can pass through our digestive system without adding calories or affecting blood glucose levels.

Chlorine’s role here might sound intimidating, but it simply alters the structure, preventing enzymes from binding and metabolizing the molecule. This structural change also makes sucralose remarkably stable, even under high heat, making it a versatile choice for cooking and baking.

---

Erythritol and Xylitol

We’re getting slightly more exotic now…

Sugar alcohols, or polyols, are neither sugars nor alcohols in the traditional sense, but they share some characteristics with both. Their molecular structures include multiple hydroxyl (–OH) groups, allowing them to interact with sweetness receptors similarly to sugars. Erythritol (C₄H₁₀O₄) is about 60-70% as sweet as sucrose but is absorbed directly into the bloodstream through the small intestine and excreted unchanged via urine, making it virtually calorie-free.

image credit: The Sweetener Book

Erythritol is used in:

1. Sugar-free sweets and gum

2. Low-calorie beverages

3. Baked goods

4. Dairy products

5. As a tabletop sweetener

Erythritol is generally considered safe and well-tolerated. I can’t seem to find any solid evidence for adverse health effects (as yet)! So here are the pros instead:

• Erythritol doesn’t affect blood sugar or insulin levels, making it suitable for people with diabetes.

• It doesn’t contribute to tooth decay and may even help prevent cavities.

• It’s better tolerated than other sugar alcohols, with most people experiencing no digestive issues at moderate consumption levels.

• Some studies suggest erythritol may have antioxidant effects, potentially offering protection against vascular damage caused by high blood sugar.

However, excessive consumption may lead to digestive discomfort in some individuals.

---

Xylitol (C₅H₁₂O₅; stucture below), on the other hand, is partially metabolized, and has a small caloric value. Due to its anti-bacterial properties, xylitol is often used in dental products as it inhibits the growth of bacteria that can cause cavities. Both erythritol and xylitol are commonly used in ‘keto-friendly’ or low-carb products since they don’t spike blood sugar levels.

xylitol innit | image credit: The Sweetener Book

Xylitol is commonly found in:

1. Sugar-free chewing gum and mints (I’ve found it in quite a few plastic-free chewing gums; and yes, I see the raised eyebrows, it is true that most chewing gums contain plastic)

2. Toothpaste and mouthwashes

3. Diabetic-friendly foods

4. Baked goods and sweets

5. As a tabletop sweetener (you would never have guessed!)

Xylitol offers several potential health benefits also:

• Xylitol significantly reduces the risk of tooth decay by inhibiting the growth of bacteria that cause cavities.

• It has a minimal impact on blood sugar and insulin levels, making it suitable for people with diabetes.

• Some studies suggest xylitol may help prevent ear infections in children. I am as surprised as you are.

• Some research indicates xylitol might increase bone density, potentially helping to prevent osteoporosis.

However, there are some considerations:

• Consuming large amounts of xylitol can cause digestive discomfort, including bloating, gas, and diarrhea.

• Xylitol is highly toxic to dogs and should be kept away from pets (keep the xylitol and chocolate to yourself people)

• While lower in absorbable energy than sucrose, xylitol still provides about 2.4 calories per gram.

---

Stevia

And now we’re truly getting exotic…

steviol glycoside | image credit: Wikipedia

If you’re a bit of a health freak (chill, I only said a bit), you may have come across stevia. Stevia comes from the Stevia rebaudiana plant native to South America. Its sweetness comes from steviol glycosides—complex diterpenoid compounds, primarily stevioside and rebaudioside A, responsible for stevia’s sweet taste. These glycosides are bulky molecules that interact with sweetness receptors similarly to synthetic compounds, yet they aren’t metabolized in the digestive tract, making them calorie-free.

While often labelled as ‘natural’ (well, I mean it does come from a plant), stevia undergoes substantial refining to isolate the sweet glycosides, making it as processed as many artificial options. Its natural origin, however, contributes to its popularity, particularly among those seeking plant-based sweeteners.

Stevia is widely used as a sugar substitute in various products:

1. Beverages, including soft drinks and teas

2. Dairy products like yogurt and ice cream

3. Baked goods and desserts

4. Baked beans (I’m British, don’t judge)

5. Tabletop sweeteners (I think I’ve seen Truvia, there’s definitely more…)

6. Oral care products like toothpaste and mouthwash

Stevia sweeteners are generally recognised as safe by major regulatory agencies, including the FDA and WHO. The acceptable daily intake (ADI) for steviol glycosides has been established at 0 - 4 mg/kg body weight per day.

Research suggests stevia may have additional health benefits, including:

• Antibacterial and antiseptic properties

• Anti-inflammatory effects

• Hypotensive (blood pressure-lowering) effects

• Diuretic properties

• Potential cardiotonic (heart-strengthening) effects

However, some people find stevia has a bitter aftertaste, which may affect its acceptability in certain products. Furthermore, highly purified stevia extracts are considered safe, but whole leaf stevia or crude stevia extracts are not approved for use as food additives in many countries. And, of course, while current research is promising, more long-term studies are needed to fully understand stevia’s effects on human health. Nothing new there.

---

A quick note on safety…

The safety of artificial sweeteners has been the subject of extensive research. The general consensus in the scientific community is that these sweeteners are safe in the quantities typically consumed. For instance, concerns over aspartame are often based on studies with doses far higher than what a person would typically consume. For most people, the amounts in products like diet sodas or sugar-free snacks are far below any concerning level.

Artificial sweeteners are also commonly linked to ultra-processed foods, which can raise valid health concerns if consumed frequently. While sweeteners themselves aren’t inherently problematic, they do often appear in foods high in additives, low in nutrients, or designed for long shelf life—qualities that can contribute to an unbalanced diet if over-relied upon.

---

What is there left to say? Well, artificial sweeteners have certainly carved out a unique space in modern diets. From chlorinated molecules that remain unbreakable in the gut to dipeptides that mimic sugar’s sweetness on a molecular level, they offer a rather impressive range of applications without the metabolic effects of simple sugars. Perhaps it’s time to see ‘artificial’ not as a warning (don’t get me started on ‘natural flavouring’), but as a nod to the ingenuity of food science…

---

And that’s all for today!

If you learned something remotely interesting from this corner of the internet, do feel free to drop a like and/or have a gander at some of the buttons below. And maybe see what happens if you press one or two? I promise the Earth won’t spontaneously combust…

…well I suppose I can’t fully guarantee…

Oh, and if you have a favourite artificial (or not) sweetener, feel free to rave about it in the comments below. I’m personally a big fan of erythritol (it has the coolest sounding name. in my opinion, at least. although I’m open to persuasion…)

See you sometime in the future (presumably)!