Comment by outworlder | Hacker News Reader

Comment by outworlder | Hacker News Reader

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> "one way in which high levels of fructose consumption promote tumor growth is by increasing the availability of circulating lipids in the blood. "

Glad to see more research on this. Until recently, people trying to sound the alarm with regards to high fructose consumption (mainly high fructose corn syrup) have been dismissed.

Excess fructose consumption increases tryglicerides, uric acid. Just uric acid alone causes a lot of issues, from heart disease to erectile dysfunction(inhibits NOX), even before gout starts. The range that's considered 'normal' has changed over time, but I feel it's too high.

https://pmc.ncbi.nlm.nih.gov/articles/PMC7352635/

Note that fruits are unlikely to be an issue (except perhaps as fruit juice). Most people don't eat enough of them and they have plenty of nutrients that are beneficial.

EDIT:

> “Interestingly, the cancer cells themselves were unable to use fructose readily as a nutrient because they do not express the right biochemical machinery,” Patti said. “Liver cells do. This allows them to convert fructose into LPCs, which they can secrete to feed tumors.”

Forgot about this. Non alcoholic fatty liver disease has been on the rise for a while now, and it's mostly the high fructose corn syrup again.

> mainly high fructose corn syrup

It should be pointed out that contrary to what many people assume, "high-fructose" does mean that it has more fructose than sugar. Sugar is 50% fructose, and many widely used HFCS formulations contain less fructose than sugar (e.g. the 42% fructose formulation used in most processed food). Even the formulation used in soft drinks is only 55% fructose, marginally more than sugar.

If you replace HFCS with sugar in your diet it is basically a no-op in terms of being healthy and in many cases will increase your fructose intake.

In table sugar each fructose is conected to a,glucose in a single molecule (so 50% and 50%).

In high fructose corn syrup they are disconected.

This cange a lot of things like how fast they get to the blood and how fast cells can use them.

I'm skeptical of a lot of good/bad reported health effects, but it's not obviously a nop.

Fructose can't be used by cells directly - it does not effect blood sugar levels, because it has to be processed by the liver into glucose first.[1]

The potential issues with fructose are related to the matabolic processes which convert it into glucose, which is what your cells actually use.

So eating say, straight fructose in fact won't spike your blood sugar since it has a much more convoluted metabolic path to consumption. Something like HFCS is more likely to be a problem because the glucose content is not in the dissacharide form of sucrose and can be directly absorbed.

[1] https://en.wikipedia.org/wiki/Fructose

It's basically a nop. You've got a ton of sucrase in the gut that breaks it down. There is a small difference in the rate of release as a result but it's not clinically meaningful.

I was recently diagnosed with fatty liver disease. The liver-related numbers in my blood work were slightly elevated. An abdominal ultrasound confirmed it.

Liver problems have historically been caused by excessive alcohol consumption (leads to cirrhosis, etc.) But I'm a teetotaler. The other version of fatty liver disease - the non-alcoholic kind - can be caused by excessive fructose consumption. Since I have been drinking diet sodas for years, that likely isn't it either (Diet Dr Pepper uses Aspartame as a sweetener).

But there are hints that artificial sweeteners trick the body into thinking they're getting the real thing and it will store those calories as fat. So I have started a fat-loss program where the first thing to go has been soda. And I'm down 15 pounds so far.

Many thanks to the "LoseIt" app developers for making it easy to track my calories. And please get your numbers checked at your next doctor visit.

Fatty liver here as well. Not a big consumer of sugar or alcohol though so I suspect something else is the cause. My liver doc ordered a couple dozen obscure blood tests to see if we can find the cause. I take a lot of supplements and vitamins, but the doc didn't see anything that should have caused it. My parents and siblings, despite being more obese and consuming more sugar, also do not have it.

Thing I read that's a bit fascinating and possibly important is your digestive system has taste buds and it's own nervous system. I wouldn't be gobsmacked if it responded to artificial sweeteners. And that causes issues.

Other thing I read is fructose is processed by the liver via some of the same paths that alcohol does. Would surprising if they didn't share some of the same negative health outcomes.

You can get NAFLD from fructose yes, but it's not the same as alcohol. Alcohol is metabolized in the liver but the pathway is very different.

Alcohol dehydrogenase (and in alcoholics CYP2E1) breaks it down into acetaldehyde. Aldehyde dehydrogenase breaks it down into acetone. Acetone is one of the ketone bodies that's then utilized as a fuel directly. Acetone is a natural ketone, but it's also toxic at high levels.

Fructose undergoes fructolysis. Fructose is phosphorylated to fructose-1-phosphate by frucotkinase. It's then broken down by aldolase B into glyceraldehyde and dihydroxyacetone phosphate (DHAP). Glyceraldehyde is converted to glyceraldehyde-3-phosphate and enters mid-way through the glucose metabolism pathway. DHAP is used to synthesize fat. Since it happens in the liver, you can get fat build-up in the liver, and NAFLD.

Is fatty liver disease also common in teetotalers / non-fructose drinkers of average weight?

I wouldn't think so, as alcohol, fructose, and/or being overweight seem to be the main factors. I would ask your doctor to look at your blood work with relation to that the next time you get a physical.

Oh, and at least in my case, it's not related to cholesterol or diabetes. I'm fine there. {shrug}

Fructose is primarily processed in the liver and shares some processes with alcohol processing with toxic byproducts. Fructose processing yield triglycerides contributing to the less ideal fat in blood. When I cut my fructose consumption down for a while to less than 10g/day my triglycerides in my blood dropped considerably - my GP did not believe it was my diet. It is shocking how little some doctors know about fructose influence on the body despite the considerable amount is is consumed.

FYI, high fructose corn syrup has only slightly more fructose (a single digit percentage) than normal sugar, which also has a fuckton of fructose in it.

Corn syrup is a red herring.

Correct. Sucrose (table sugar) is exactly 50% fructose, 50% glucose. The most common blend of HFCS is 55% fructose, 45% glucose - which is barely different. https://en.wikipedia.org/wiki/High-fructose_corn_syrup

That link has a bit of nuance. Some HFCS has lower fructose content:

"HFCS 42" and "HFCS 55" refer to dry weight fructose compositions of 42% and 55% respectively, the rest being glucose. HFCS 42 is mainly used for processed foods and breakfast cereals, whereas HFCS 55 is used mostly for production of soft drinks.

Yup. ~5% more fructose than table sugar in its most common formulations, actually lower content than table sugar in some formulations (e.g. HFCS-42). The 'high fructose' moniker is derived from a reference to 'pure' corn syrup which is nearly 100% glucose, not a reference to table sugar as commonly assumed.

Right. The main issue with HFCS is that it's really cheap so it gets added to a lot of things that wouldn't normally contain sugar or it is added in greater amounts than other sugars.

I've heard the issue with high fructose corn syrup is that the levels of sugar in it does not correspond to its sweetness level. Corn syrup on its own is not very sweet, so to make it taste sweet you have to add much higher levels than if you had used other types of sweetener.

It's the opposite. You'll add more sucrose to hit the same sweetness experience as most HFCS blends, not less.

Not sure how to square that with the chemical composition of hfcs.

> Glad to see more research on this

You are glad to argue for exactly the opposite of what the research found?

Fructose is metabolized to lipids in the liver and that counts fruit juice, too. And the whole fruit.

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