But OTOH, sugar is associated with a myriad of health issues. So the relevant question becomes, is (for example) Diet Coke worse for your overall health than regular sugar-laden Coke? The best info I can find is that the evidence is mixed and inconclusive as to which is worse. Artificial sweeteners definitely lead to less weight gain, but may (or may not) introduce other risks. The evidence is confounded by the fact that people who choose diet drinks are already at risk of obesity or diabetes.
I’d also like to see a breakdown by different kinds of artificial sweeteners. There are a bunch on the market, and it seems implausible that they’d all cause the same health effects.
My understanding is that is in fact not the case, not in actual use cases, so cite please?
As stated earlier in this thread it may be that these products are relative harms reduction to added sugar products. One the choice of no or rare use of added sweetener shouldn’t be dismissed as impossible. Two it is not at all clear there is harms reduction.
On further research, your understanding may be correct, so no cite and my apologies. There is some evidence that artificial sweeteners may actually cause an increase in body fat, but it’s not clear that the full story is yet in.
I’ve read a lot of studies about artificial sweetener, and i think the answer is “people are diverse, and re l different people react differently to them”.
In particular, i suspect there are systemic differences between the impact of artificial sweetener on people who aren’t accustomed to them and on people who are accustomed to them.
As someone who relies on my appetite to tell me when to stop eating, i don’t want to mess that up by eating fake foods that might confuse my appetite. But i suspect many American adults have already gone past that point.
I fortunately don’t have much of a sweet tooth, but I do like a bit of sweetener in my morning coffee. What I use these days is a couple drops of monk fruit extract-- not the granulated monk fruit, which is bulked up with erythritol, a substance strongly correlated with blood clot formation and other issues, but in liquid drop form, which consists of purified water, monk fruit extract, natural flavors and citric acid.
So far everything I’ve read says that monk fruit extract is generally considered safe, though I wouldn’t be surprised if a study eventually comes out saying something like ‘use of monk fruit extract strongly correlated with growing extra limbs, and / or spontaneous falling-off of limbs and other extremities’ 
That review (link to full article provided) is long on fevered speculation but short on confirming data, There’s a lot of handwaving and posting of flowcharts not tied to specific references listed at the end of the article.
The lone author laments:
Using words like “significant”, “vividly” and “repercussions” suggests the author might have gone from sober scientist into being a true believer and advocate.
A reference for his warning about the “delicate gut-brain axis” is “Adverse Childhood Experiences: The Neuroscience of Trauma, Resilience and Healing throughout the Life Course”. It’s a book dealing focusing on health effects of trauma on children. Unless one of those traumas is drinking Diet Coke, it’s hard to see how it fits into his thesis, other than potentially mentioning a “gut-brain axis”.
No doubt artificial sweeteners and health is a field worthy of further study. It’s well to be cautious about sweeping statements made on the basis of scant evidence that depends significantly on studies in rodents, which frequently don’t translate to findings in humans.
In the Brazil study they state -
Consumption of aspartame, saccharin, acesulfame k, erythritol, sorbitol, and xylitol was associated with a faster decline in global cognition, particularly in memory and verbal fluency domains.
They have enough similarities to hit the same sweet centers with great potency so having similar adverse effects doesn’t seem like a huge stretch. But again could be a marker of risk, either early disease, or as suggested by @puzzlegal , of predisposition.
Changes in brain signaling pathways have been documented in animal models for several of them.
Another animal model for plausibility with aspartame:
And erythritol
https://journals.physiology.org/doi/full/10.1152/japplphysiol.00276.2025
Sucralose.
https://onlinelibrary.wiley.com/doi/full/10.1002/fsn3.4488
Just quick searches. Again not proof that these things happen in humans but biological plausibility consistent with the findings.
The above to you as well @Jackmannii. The rhetorical grandiosity and poor citations listed) does not dispute the findings, consistent with the findings in the Brazilian population, of a solid association of cognitive decline with higher artificial sweeteners use, consistent with higher neurodegenerative mortality with ultraprocessed foods driven most by the association with sweetened beverages including those that use artificial sweeteners, in more than one study, and that by those cites have a plausible biological mechanism of action demonstrated in animal models.
Still not a slam dunk but hard to get a stronger case in the real world.
Well, they all fit into the same receptors in taste buds. Does that translate into all of them passing through the blood-brain barrier in the same way? Maybe… but I’m skeptical.
Did you look at the citations?
From my perspective I don’t care if the brain tissue impacts are all caused by them all crossing the blood brain barrier, or the downstream impacts of disrupts gut tight junctions or microbiome dysbiosis or dysregulated immune function or whatever. I see that the group has multiple members that can result in altered neuronal pathways and supporting cells.
People and other mammals have learned reactions to food. That represents a change in the brain, influenced by our sensors of food (primarily taste and smell). It’s plausible to me that God’s that we sense similarly that have similar nutritional value would have a similar impact on the brain.
(I was going to write out a long list of “learned reactions to food", but i doubt it’s necessary. I’ll just say that there is clearly a feedback loop between how we perceive food and the nutritional impact of that food. People grow to like nutritionally valuable foods, and rapidly develop dislikes for a food if they get sick a few hours after the first time they eat it – even if they know the food has nothing to do with their illness.)
There do seem to be some shared negative effects due to the body reacting to the “sweet” attribute that gets picked up by your taste buds. The only way to resolve that is to reduce your total and peak intake of sweetness, in general.
But yeah, Xylitol appears to be on the bad side of things. Inulin might be a net positive with only a mild sweetness, being a healthy fiber, and (potentially) acting like a minor GLP-1 agonist. Overall, there’s probably 30 or so different substances and while a significant percentage are sugar alcohols and might have shared chemistry, most of the others are quite diverse and unrelated. Treating all sugar substitutes as one class is almost certainly unreasonable.
Currently, I favor Monk Fruit (mogrosides), allulose, and inulin. But, reducing your dependency on sweet flavors is also a good target, most likely.
This is what makes the most sense to me. I hate carbonation, so I never developed a soda habit. But I do drink coffee and tea - with no sugar or sweetener. If you’re accustomed to unsweetened beverages, added sweetener of any kind tastes awful.
Someone I used to know, an avid coffee drinker who never used sugar, always said, “Good coffee doesn’t need sugar. Bad coffee doesn’t deserve it.” Words to live (healthily) by!
There’s also a lot of excluded middle between “don’t add sweetener” and “make it as sweet as American mass-market soft drinks”. When I make a cup of tea, I add one teaspoon of sugar, or about 16 Calories worth. A 12-oz can of Coke, meanwhile, has 140 Calories worth of sugar, or almost 9 times as much. I’m still drinking a sweetened beverage, but it’s a lot closer to unsweetened than it is to Coca-Cola.
Sequence of threads inspiring each other follow back to one in FQ on coffee and chocolate and milk. In there I posted a study that looked at milk/cream and sugar having possible impact on coffee’s positive health impacts.
Low sugar was as positive as black coffee. That’s the good news. Bad news? The cut off for low was half a teaspoon per cup.
What was the methodology? Did they test one category of “low sugar” with half a teaspoon, and then another category of “high sugar” with 8 teaspoons, or did they test every half-teaspoon interval from 0 to 10, and found that the benefits disappeared between 0.5 and 1.0?
Sweeteners have been studied much more than most chemicals generally recognized as safe, and many of the studies against them have used misleading data and alarming language.
This does not mean all sweeteners are the same, or that they might cause problems including chronic disease, “changes in the gut micro biome” (already a poorly understood topic), “chronic inflammation” (a term as much of a ‘catch-all of garbage’ as adding ketchup to your hot dog), etc. it just makes it hard to consider singular criticisms meaningful. There is some slight evidence against them. The marketplace will certainly speak - if something is dangerous, it will attract liability.
It makes sense to reduce consumption of sweet things, both added sugars (I don’t bother counting whole fruit and vegetables, or natural sugars in dairy) and sweeteners. However, if you are human and find sweet things delicious, I suggest using glucose over fructose, sweeteners that have been around longer, and remembering what Parcelsus said about anything being toxic in a high enough dose. This answer is not satisfying? I agree. It’s still almost the best we got.
I don’t have access to the whole article to be able to answer the methodology question.
My suspicion is however that you are exactly right - a tsp of sugar is likely no biggie. I suspect the impacts of added sweeteners is indeed at the level of a can of Coke or Diet Coke, or a frappachino, not at the tsp in a cuppa level.
You buy pure glucose for your sugar use? Most of us have table sugar (sucrose) which is half glucose half fructose same as high fructose corn syrup is. Fancy man!
I do buy glucose, which is not much more expensive than table sugar, but takes more work to find (any bulk store, better supermarkets). I also eat a lot of fruit, whole or in smoothies. I have been fairly successful at reducing my overall sugar intake, and use mostly sweeteners in hot drinks. I don’t actually add a lot of sugar to most stuff, or bake much post-pandemic, finding a little goes a long way. My biggest addiction is still diet cola.
Wiki says:
Aspartame Content in Coca-Cola Zero Sugar
Coca-Cola Zero Sugar contains aspartame as one of its sweeteners. The amount of aspartame varies depending on the size of the beverage.
Aspartame Amount by Volume
| SIZE OF COCA-COLA ZERO SUGAR | ASPARTAME CONTENT |
|---|---|
| 355 mL (12 oz) can | 85 mg |
| 500 mL (16.9 oz) bottle | 100 mg |
| 1 L (33.8 oz) bottle | 200 mg |
| 2 L (67.6 oz) bottle | 400 mg |
Daily Consumption Limits
The acceptable daily intake (ADI) for aspartame is set at 40 mg per kilogram of body weight by the World Health Organization. For a 70 kg adult, this translates to a safe limit of 2,800 mg (2.8g) of aspartame per day.
Summary
In a 1-liter bottle of Coca-Cola Zero Sugar, you can expect approximately 200 mg of aspartame. This amount is well within the safe consumption limits established by health authorities.