Germs That Love Diet Soda
nytimes.com
nytimes.com
Different diet sodas use different artificial sweeteners, so diet soda cannot be treated as a single group. Diet Coke uses only aspartame as sweetener; Coke Zero combines aspartame and acesulfame K to create a more realistic taste.
I readily believe that any diet soda sweetened purely with aspartame is harmless. The chemical structure of aspartame is such that stomach acids should break it down into aspartic acid, phenylalanine, and methanol, the first two being ordinary amino acids. Methanol sounds threatening, but very little aspartame is needed to sweeten a beverage. I thus have no problem drinking diet coke.
What's more unclear is whether the sugar-like taste of artificial sweeteners affect the body's blood sugar regulation.
You also have to consider other additives in the soda, such as acids that can damage your teeth, and the caffeine in diet coke.
"should", but it's really hard to find reliable information as to what actually happens since the internet is filled with FUD websites claiming aspartame gave their brother/grandma/cat/chair cancer.
> Methanol sounds threatening, but very little aspartame is needed to sweeten a beverage
Methanol is very toxic to humans, so that's a good thing.
> What's more unclear is whether the sugar-like taste of artificial sweeteners affect the body's blood sugar regulation.
Why would it?
I believe the theory goes something like: the taste of sweetness causes changes in the body in preparation for a carbohydrate load.
How much truth there is in this claim is left as an exercise for the reader.
From https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3916844/ :
> Carbohydrate (CHO) mouth rinse is defined as a CHO fluid distribution around the mouth for 5 to 10 s with subsequent expulsion by spitting. The utilization of either a low-concentrated 6.0% to 6.4% glucose or partially hydrolyzed maltodextrin are the most common CHO used, with the latter being colorless and tasteless when dissolved in water.
...
> CHO mouth rinse seems to improve performance during moderate- to high-intensity exercise (~60% to 75% VO2max), of at least 1 h duration. It is probable that the mechanism involved in this improvement may not be metabolic but neural, via oral CHO receptors (glucose and maltodextrin) that activate brain regions related to the sensation of reward and pleasure.
Note that it apparently isn't taste that is having the effect, as (according to this paper) maltodextrin, when dissolved in water, doesn't have a taste. So apparently there's some mechanism other than either ingestion (metabolic) or taste.
I meant my last line not as a disputation against, but only as an indicator that I was, at the time, too lazy to provide references.
The burden of proof should probably be on the side of those asserting safety of novel food components, and if that means waiting a full generation for the data to come in, so be it (note that animal tests don't really tell us enough, because metabolism doesn't seem that well conserved between species; there are plenty of things that humans can eat safely that animals can't and vice versa)
Human metabolism and our food has coevolved over thousands of years, and we have evidence in the fossil record that shifts in diet (e.g. agriculture, pastoralism) had negative impacts on human health (worse teeth, shorter, weaker bones) until either our genomes or microbiomes adjusted.
If you decide to consume large quantities of novel ingredients in combinations that no humans have ever eaten before in our evolutionary history, then sure, it may turn out just fine—but metabolism is an intricate dance and there are a lot of ways to screw it up.
"Eat food, not too much, mostly plants." and "Don't eat anything your great grandmother wouldn't recognize as food." seem like sensible advice for people who can afford to follow it [1].
[1] https://www.webmd.com/food-recipes/news/20090323/7-rules-for...
I think we're pretty close to having a full generation's worth of data, considering it was approved by the FDA in 1981.
What's wrong with seltzer?
I wonder what is the pH of glass of carbonated water with a squeeze of lime?
Remember that I mentioned moderation though? A glass or two of OJ, lemonade, tea, coffee, or seltzer a day isn’t going to materially impact your health assuming you’re not diabetic, and practice good oral hygiene. There are also many worse things for your teeth than seltzer, such as potato chips, and poor oral hygiene. If most of what you’re drinking is water, don’t sweat the glass or two of something other than water. Unfortunately too many poeple drink very little unadulterated water, and it does impact their health.
Moderation is the key.
('Notable cases' include recorded death.)
That said, the amount of ways your body adapts to osmotic balance problems is in the dozens, so poisoning your body with water, while possible, is hard to the tune of it requires something like drinking 20 liters of water in less than an hour. I mean, it seems to be possible but I cannot imagine succeeding at that even if I'm trying. That's 2 full buckets (and that's just LD50, as in, if you're >70kg it's more than that).
There is an exception: purified water. You cannot drink mineral-poor* or distillated water safely in even small quantities. Why not ? Because that will locally, suddenly and very strongly disrupt the osmotic balance in what you bring it into contact with. It probably not kill you (not without repeated application), but it may cause serious issues in your mouth, throat and stomach. It should also not be used to make coffee or tea and drunk, that merely lessens the effect it doesn't stop it.
* mineral-poor water is something used in chemical and medical laboratories
Acidity of most beverages on its own is usually not problematic as saliva (buffered at 6.5 pH) rapidly restores normal pH. It does become an issue if the salivary glands are damaged (as in the case of meth users) or stomach acid comes into contact with teeth.(severe acid reflux or bulimia) However these cannot be considered normal.
The number one cause of dental cavities is always sugar.
So no, there is a rebuilding process, but the kind of damage done by acidic substances (including the excretions of bacteria) can sometimes be reversed to some extent. The trend is usually erosion however, and moderate intake of something like seltzer or soda is at least an order of magnitude less than straight water. In addition, while water toxicity is a thing, you’d have to overcome a pretty strong urge to vomit. Short of that, water is doing you no harm, and will never contribute to the erosion of your dental enamel.
A number of toothpaste brands in Japan claims to remineralise teeth with a hydroxyapatite based formula but the results are yet to be confirmed.
Dentists have been using zinc oxide gels and other material to seal exposed dentin but the results are mixed and eventually the filling will fail. Once cavities reach a certain size not much can be done about it.
My kids have no cavities / perfect teeth. My wife and I, by that age range, had tons of cavities.
More acidic than: water milk tea ice tea beer
About that same as: coffee (coffee with milk, however, is essentially not acidic) wine (depends a bit on the kind of wine, sweet wine is less acidic) orange juice (from sweet oranges, the sour ones are usually less acidic)
Less acidic than: lemon juice (coke is a LOT less acidic than lemon juice)* grape juice (esp. when adding lemon juice for more sweetener) lime juice things like "lemon ice tea" (and of course actual tea with lemon in it. It depends on how much lemon. If you add enough lemon to allow for much additional sweetness, it will be a lot more acidic than carbonated beverages)
With fruit things can vary. Apparently the rule is, the sweeter, the more acidic (the opposite of what your tastebuds will tell you, although it's really more a case of if you taste sweetness you ignore sourness. Sweet taste doesn't necessarily mean something is acidic, obviously, but (from a certain level) it does mean you won't notice at all whether something is acidic or not, or how much).
If you're worried about this, even a small sip of milk will eliminate any acidity in your mouth in seconds (milliseconds actually).
* I've heard of medical cases where people managed to dissolve their stomach lining by drinking pure lemon juice (about 1.5 liter), and died due to the stomach juices coming into the abdominal cavity. Yes, that's right, your stomach lining, specifically designed to be able to handle strong acidity, cannot deal with lemon juice.
I would like to know what feedback path could possibly exist to enable this.
Some other artificial sweeteners, like saccharin, aren't nearly as sweet per molecule, and you have to add a lot to get the desired effect. They also have an apparent effect on glucose intolerance related to one's gut biome, and it's not due to the taste - you can transfer the biome alone between mice and get a similar impact.
Example source: https://www.nature.com/articles/nature13793
E.g. it seems to affect brain functioning IIRC
I think the article is saying that it isn't that simple, because even small amounts of certain additives can change the microbiome.
More articles:
https://www.npr.org/sections/thesalt/2014/09/17/349270927/di...
https://www.scientificamerican.com/article/artificial-sweete...
At least according to a BBC documentary http://www.bbc.co.uk/programmes/articles/51yxBQyvqpNYPT3PF0L...
How is this unclear... every study I've seen shows that artificial sweeteners are similarly obesogenic to actual sugar. Some of them also spike blood sugar quite a bit.
Several studies have also showed that artificial sweeteners change gut bacteria. One study I can't find right now showed a single dose of sucralose significantly changed gut bacteria composition. Here is an article about this concept from Sci Am https://www.scientificamerican.com/article/artificial-sweete...
Diet coke has no sugar, no fat, and less than 100 mg sodium. The specific results from Nature are about trehalose, a sugar not found in diet coke. I'm not aware of any diet soda that contains it, either. I realize it's an opinion piece, but pseudoscience and speculative articles should not be the domain of NYT.
Of note, the zero-calorie definition of artificial sweeteners is based on the amount excreted in urine/stool: It should be very close to the ingested amount. I find it hard to believe the conclusion drawn by the authors that other sweeteners (sucralose and saccharin), are consumed by bacteria since the amount ingested matches the amount excreted.
The prevalence of inflammatory bowel disease has, it’s worth noting, sharply increased in recent decades.
Then there are artificial sweeteners like sucralose and saccharin, which we consume in diet sodas and “sugar-free” snacks in hopes of cutting calories. Our bodies can’t directly digest most of them — they’re meant to pass right through — but it turns out that the microbes inhabiting our colons can metabolize the sweeteners, potentially to our detriment.
Scientists at the Weizmann Institute of Science in Israel have found that, in mice, saccharin causes glucose intolerance, a marker of impending diabetes — and one disease that those who eat these sweeteners are probably trying to avoid. When the scientists transplanted microbes from mice fed saccharine to mice that hadn’t consumed the sweetener, the recipient animals developed glucose intolerance as well, suggesting that the microbiome that was warped by the sweetener, not the sweetener itself, was causing the problems.
The only one I can think of is Tab. I tried it once, and I couldn't finish a can.
"To determine the effects of NAS on glucose homeostasis, we addedcommercial formulations of saccharin, sucralose or aspartame to the drinking water of lean 10-week-old C57Bl/6 mice"
"Notably, at week 11, the three mouse groups that consumed water, glucose and sucrose featured comparable glucose tolerance curves, whereas all three NAS-consuming mousegroups developed marked glucose intolerance (P , 0.001, Fig. 1a, b)."
The article probably only talks about saccharin specifically because, as the study states: "...saccharin exerted the most pronounced effect, [so] we further studied its role as a prototype artificial sweetener."
(Trying to find another source, I believe Diet Pepsi from a fountain does as well, to extend shelf life.)
"The scientists also fed a small group of healthy people saccharin-sweetened drinks for a week. In a subset of volunteers, microbial shifts occurred, accompanied by mounting glucose intolerance. So for some people, diet sodas may not be any healthier than regular sodas."
"Dietary trehalose enhances virulence of epidemic Clostridium difficile"
The point isn’t about one specific chemical, but rather the principal that the prevalence of non-nutritious, edible chemicals seriously augments the dark, warm controlled environments of our guts.
Nutrient capture as a whole, shifts in a way that, at the bottom of the tract, there are chemicals that humans leave unused, but which are still useful to certain opportunistic organisms.
If only those chemicals are available, and normal food is absent, every member of the environment is forced to deal with scarcity, and the strongest survive, and fill the void if they can.
If those organisms are forced to opperate with greater efficiency, then their capacity to deal with adversity offers them an advantage as an invasive species, and they will prevail in general, everywhere, not just in the adverse scenario.
Which other diet sodas were identified as having "germs that love diet soda"?
The studies show effects for trehalose and saccharine. No diet soda contains trehalose, only Tab contains saccharine.
Any effect from the non-nutritive sweeteners in other diet sodas did not appear in the studies, so they focused on saccharine.
There may be more subtle effects from those sweeteners, or future effects from those sweeteners, but we haven't found them yet, extrapolation from a general principle not withstanding.
"Germs that love Tab" wouldn't draw as many clicks as the current title.
https://www.foodnavigator.com/Article/2008/04/17/Coca-Cola-w...
Supposedly diet coke from fountains contains saccharine
Later versions of the product lowered the amount of fiber content, but this did not stop the reports of gastrointestinal problems.
In every test done with a different substance the question needs to be, how much was it given to the subjects? (g/kg body weight). A lot of tests are done with excessive amounts (which are fine for testing purposes, but doesn't mean the effect will be as pronounced in smaller amounts)
I'll get the sugar-free soda as opposed to something that is the definition of high glycemic index empty calories. Or even better, just water.
Every time I've lost a significant amount of weight (currently at -70 lbs from my peak) it's because I have drastically reduced sugar/carbohydrate content---while continuing to guzzle aspartame-based diet soda like water.
So either: 1.) I'm an outlier, 2.) These results are only relevant to saccharine sweeteners, and not aspartame, 3.) These results are bunk, like so many other nutritional studies, or, 4.) Low carbohydrate intake offsets any negative effects
Even where the article discusses diet sodas, it doesn't specifically say that they inhibit weight loss but that they might cause other kinds of harmful metabolic effects through their effect on the microbiome—and that this mechanism is suggested by research but not yet well-established. It also admits that some of those effects, if they exist, could vary widely between people.
That might be one reason that evidence nutrition has seemed so hard to pin down: if many of the effects depend on people's microbiomes, then some studies might be almost impossible to replicate in a different population, or maybe even in a different generation of research subjects. It might be true that some large group of people did very well eating one way, and that a different group did very well eating very differently, even if it seems like the advice that you'd draw from these observations is directly contradictory.
Soda is bad for other reasons too. The carbonic acid will rot your teeth.