It feels like the actual paper "Gut microbial taxa elevated by dietary sugar disrupt memory function"[0] is both a better headline, and a better link, than this inaccurate editorial post (playing on the "Sugar and spice and all things nice" song?).
The paper is from March/2021, and there was discussion on HN then: 91pts, 27 comments [1]
According to Google's scraping of the USADA data, 40% of the calories in human breast milk are from sugar. That alone makes me question if sugar is really terrible for brain development in children.
The sugar in milk is lactose (glucose + galactose). Soda is basically fructose and glucose. So the glucose if common between the two.
I want recommendations of "don't eat sugar" to dig into the details, because sugar is everywhere. My mother-in-law "doesn't eat sugar" but constantly snacks on figs/dates, pours honey over everything, and drinks fruit smoothies daily. In my opinion, she has a very high sugar diet despite not adding any table sugar or corn syrup to anything. Many recommendations say to limit "added sugar" without explaining why naturally occurring sugar is okay.
Here’s the best explanation I’m aware of. It’s long but worth it. It changed how I think about food. I’ve been much more successful in eating healthily now that I understand how the body processes different types of sugar. Refined sugar (fructose) is poison.
What a great presentation, I hadn’t seen this. My question would be: what of the diet or zero calorie products? I heard they make you overconsume later because basically they are anti-satiating. Would be interested to know.
Sucrose is table sugar, and fructose is the sugar found in fruit and veg. Fructose is also often used as an additive in the form of high-fructose corn syrup. Unfortunately fructose is even worse for you than sucrose, despite fructose occurring in otherwise healthy foods.
I'm not a big fan of sugar, and I regret that I even avoid fruits on account of them being too sweet. Some apples are sour, but that's not preferable either.
What's a nice fruit that's not bred to be way too sugary?
Because this has come up twice in the last few days, here's a quaint introduction to the different kinds of sugar (glucose, lactose, sucrose and fructose) from a movie called "That Sugar Film".
- Sucrose (i.e. table sugar) is 50% Glucose and Fructose
- Frutose is bad.
Longer version: Fructose is naturally quite rare, and presumably we've adapted to that; our bodies can only process small quantities effectively. It's also the sweetest and (implied?) most addictive of the sugars. These days we can manufacture it though, so it turns up in just about every sweet processed food it can.
EDIT: After watching the lecture linked by sul_tasto below (https://news.ycombinator.com/item?id=29849184) it seems it's just a question of fructose quantity and prevalence rather than the body processing it differently from other sugars.
Fructos is plentiful in fruits which we must have been well adapted to consuming.
I don't understand the argument against fructose. It seems to mainly "the liver has to work to digest it", but isn't that true of a lot of other nutrients as well? I mean, that's the main function of the liver, so the fact that fructose engages the liver should not by default imply that it's bad.
As usual in biochemistry, it is the dose that makes the poison. But also mode of consumption.
We are indeed well adapted to consuming fruit. Even though modern fruit is bred to be much more sugary than its natural predecessors (ever tried eating a wild apple from a tree on a hike? Insanely sour), there does not seem to be any kind of health problem associated with consumption of raw fruit. We have a lot of metabolically sick people around the world - over a billion probably - but few of them, if any, have gotten to that point by eating too much fruit.
Fructose is not fruit, though. Even very sweet fruit like mango has only 16 per cent of fructose per weight. Fructose itself is 100 per cent, it is refined, concentrated stuff, from which all fiber has been removed.
Fiber that naturally occurs in fruit and veg slows down processing of fruit and veg in the digestive system - it takes fairly long (hours) to extract all the fructose from an eaten piece of fruit. As a result, the liver isn't overworked - it receives manageable quantity of fructose over a long period.
Now compare a situation when you drink a litre of sweetened beverage. That is a lot of fructose - you just drank an equivalent of seven? eight? apples in half an hour or so. And all that sugar comes in liquid form, so it enters your blood very fast, producing a huge spike. The liver is overwhelmed. It can cope somehow, but do this ten thousand times and some negative outcomes are bound to follow.
There is a scientist (Robert H. Lustig, professor of endocrinology at UCSF) who, more than a decade ago, published a long video called "Sugar: The Bitter Truth". It is stuffed with various biochemical observations and longish, but I found the information useful.
Ok but this does not only apply to fructose. It applies equally well to glucose and fat/oil. Anything in excess can had dire consequences, including a lot of vitamins and minerals. Even water in excess can be bad for you.
When the messaging is centered around "carbs are bad" or "fructose is bad" it will lead people to believe that fruits are bad for you. I've seen several health channels on youtube recommend not eating more than the equivalent of one apple per day in terms of fruits.
Glucose can be processed by every single cell in human body. I don't think you can eat or even drink so much glucose that you overwhelm the capabilities of the entire body to cope with it. You will vomit sooner than that.
While people can and do consume excessive amounts of fat/oil, we are somewhat protected by the fact that fat has a very strong satiating effect, which makes it a little harder to completely pig out. Fructose has no satiating effect at all.
Generally, yes, anything in excess has dire consequences, but in some things those consequences manifest sooner than in others. Sweetened beverages as consumed today are very much a definition of excess: big packaging, a lot of sugar within, and their mass consumption is societally normalized.
> Glucose can be processed by every single cell in human body.
That processing hinges on a healthy insulin response to keep blood sugar levels in check. Which for a large part of the population is probably not the case.
Again with a suitable amount of fibres to go with that glucose intake, the load can be levelled somewhat though.
From that same video linked by the parent post (https://youtu.be/dBnniua6-oM). I watched it a while ago, so in my own words:
The key is fiber. When you eat fruit, you consume fructose with fiber. Fiber hinders absorption of fructose. Many processed foods have a lot of fructose and no fiber, because fiber doesn't help the shelf life.
You're right about the liver but as ever the question as to whether something is bad for us comes down to how much we consume. Apple seeds along with a number of other fruits contain amygdalin which breaks down to cyanide. So there's cyanide in apple juice but we'd have to drink several tens of liters of the stuff to reach anything approaching a lethal dose. We can handle small amounts of cyanide. Similar story with fructose, admittedly on a rather different level. However the dangers are real.
My thoughts exactly. I remember reading about some indigenous tribes in Africa whose diet is mostly just fruits.
You could maybe make an argument that the fruits we consume now are a result of hundreds of years of selective breeding and contain much more of it than indigenous plants.
Raw natural fruit is more than 90 per cent not-fructose. Probably more than 95 per cent, given that it wasn't bred for centuries to increase sweetness.
This vast majority of not-fructose plays a great role in the overall digestion process.
Fructose is refined product. These tribespeople do not eat refined fructose, they eat fruit which is much more than just fructose.
Already covered by inglor_cz, but for posterity, the first EDIT is incorrect - in addition to quantity problems, Fructose and Glucose are processed very differently in the liver.
Fructose impact on the liver is much more like Alcohol than Glucose.
IIRC fructose is perceived as roughly twice as sweet as glucose, so you would need to use more sugar if you used glucose; I'm guessing that would be more expensive, otherwise HFCS would be less economically sensible.
So it wouldn't make sense for many commercial products, but why aren't health conscious people using it at home to sweeten their tea? Also, why aren't there "premium"/"healthy" products using glucose instead of plain old sugar as a selling point?
Funny, I drank a lot of sugary soda as a kid (real sugar, not HFCS) and ate lots of candy. I still managed a long career as a programmer until last year.
I wonder if there is more to this study than simply sugar consumption; perhaps its in combination with other dietary factors, or even HFCS instead of plain sugar, or a different type of microbiome from back then compared to more recent times (different diet in general compared to 5o years ago).
I also wonder if any developmental effect measured when a child is still young is eventually overcome over time.
The study is around memory function development. You really don't need good memory to be a programmer. I have googled code questions and came across my own answers on SO. It happened more than once.
> You really don't need good memory to be a programmer.
That’s not memory, that’s hard disk (or I guess SSD for you youngins’). You definitely need good memory to be a good programmer because large problems require a larger working set to efficiently reference whilst problem solving.
While many problems in computer science that can theoretically be solved with a small amount of memory and a large amount of slower disk, many of them cannot be solved in what we’d consider a reasonable amount of time.
You're being disingenuous, when people(including the comment you're replying to) say "memory" when they're talking about people they obviously don't mean the same thing as when you're talking about a computer. He's clearly referring to his longterm recall which is directly analogous to "hard disk" as you put it.
OP obviously is talking about the human memory and for sure we don't have a hard disk, if at all, we have volatile memory. Power it off for long enough and all is gone.
GP appears to have been programming for quite some time and thier career predated Google. I remember programming before SO and Google- you had to be able to recall a lot more things from memory to get something working, although not having to worry as much about security, networking, etc… often made things easier.
Ugh, this again. Animal models are excellent predictors of physiological responses in humans if they are used correctly. If you don't think this one is being used correctly, please tell us why.
The "pple aren't rats" line is a knee-jerk response that adds nothing of value, save for revealing the ignorance of the person who utters it.
It was more a comment on the headline which explicitly mentioned “your child’s…” Meanwhile, it’s about an early study which only suggests that we should do more research in the area.
I have a degree in the biomedical sciences and I often see CS majors/software/math folks insert clear cut divisions between terms and things than could possibly correlate.
I feel like a lot of people don’t understand how continuous certain parts of biology are (and aren’t).
Different human populations have different microbiomes. Different mouse strains do too (presumably rats as well). Never mind the other (significant) differences between mice/rats and humans, wrt nutrition. The fat and protein content of rat milk is quite different to that of human milk, for example (yes, early development in these animals is also quite different, so it's not a simple "they need high protein, we need low" story -- it's just an example of the kind of meaningful differences that exist).
So I think it's pretty important to note "this is just in rats so far". It doesn't mean 0 predictive power. But it's far from solid that the effect transfers to your average US citizen, for example. IMO, these types of animal studies are useful guides for further (hopefully human) research, but shouldn't influence your day to day behavior, or the choices you make for your child. There's ample reason to avoid empty calories from sugar for pure nutritional reasons anyway, based on human studies.
But what is the likelihood that this result applies to humans vs. doesn't apply to humans? It doesn't sound like you can say. There are also differences even between two different humans. Simply being different is not enough to discount a result using a model that has otherwise proven successful.
I'm absolutely confident I can discount it in the sense of "reduce its predictive power" compared to a study in humans, but I already said I'm not discounting it in the sense of dismissing it entirely.
> It doesn't mean 0 predictive power.
BTW, I also think that most of the time you shouldn't change your daily behavior based on one single human study.
I have a degree and I'm extremely suspicious of any study that wants to extract strong statements from only experimental evidence connecting (1) a very basic ingredient of just about any foodstuff (2) the gut microbiome and (3) "memory function" as only observed through further experiments.
You could make your career from studying just tiny tiny parts of 2 or 3 but instead we got a study that is trying to solve for the world.
Rodent models are widely used for studies. Do you have particular concerns about them being used in this study to gather implications on human diet and health?
The natural diet of the rat and the human are quite different. This alone would make me question any dietary studies using rats.
Imagine if they used cats instead, which are almost wholly carnivorous. Or cattle, which live mostly on the foliage of plants. How applicable to humans could the results be?
If that’s how you view all studies then by all means let your kids drink coke and eat donuts all day.
But as someone who consumes alot of sugar and actively tries to prevent my child from consuming sugar. I appreciate these studies that give us insight into the affects of sugar on children. Gives me more motivation to prevent my child from getting too much sugar.
You'll have to do your own research on that if you want to know.
I don't have any horse in this race, personally. I don't have kids and don't have plans to pop any out of me, so I don't feel the need to investigate further.
But I still want to point out no one in this thread so far has any data or experience interpreting it to claim "my kid is not a rat, therefore the study means very little."
I'm happy to be proven that rats aren't a good indicator for what the article claims though.
There's a lot of bogus academic papers out there, especially within the past 10 years.
But I'm also not going to interpret it with my "gut" feeling of rat != kid on this because it's way out of the scope of what I understand. There's better people outside of hacker news comments that can explain this stuff better.
The paper is from March/2021, and there was discussion on HN then: 91pts, 27 comments [1]
[0]: https://www.nature.com/articles/s41398-021-01309-7 [1]: https://news.ycombinator.com/item?id=26667037