Fructose in diet enhances tumor growth: research
source.washu.edu
source.washu.edu
However, it sounds like we should maybe be avoiding excessive amounts of certain fruit. See: A Definitive Guide to Fructose Content in Fruit [1]
There was a recent episode from Diary of a CEO with a cancer expert. He seems to have some really sound advice. One particular take away for me was his finding that when the body enters a ketogenic state due to fasting the body produces defences that eat up cancer cells [2]
[1] https://iquitsugar.com/blogs/articles/a-definitive-guide-to-...
As with everything, mileage will vary.
Pro: https://pmc.ncbi.nlm.nih.gov/articles/PMC6375425/
Contra: https://www.cancer.columbia.edu/news/study-finds-keto-diet-c...
“We did indeed see that the ketogenic diet suppressed tumor growth — but we also saw, surprisingly, that it promoted tumor metastasis,” says Gu. “That was really a shock to us.”
Almost all body tissue can run on ketones instead of on glucose, except for certain important tissues like red blood cells, 30% of the brain, retina, some kidney tissue, etc.
For the rest, your body synthesizes the glucose it needs via gluconeogenesis from some protein substrates and from glycerol backbodes from triglycerides. These inputs can be either from the diet or from your fat stores.
Fasting for a few days causes your body to enter authophagy through the inhibition of mTOR in addition to ketosis, so that could account for some of the difference.
For context, I've been following IF for a couple of years. I can definitely see myself losing my resident body fat, which is encouraging. I had tried keto diet before that - I found it very difficult to sustain, especially when you're away from home or are at work. So, part of my motivation to do IF instead of keto is, well, that I can achieve some level of ketosis via IF, and without following a strict keto diet.
It's mostly a function of what you eat when you do eat.
Generally vitamins aren’t helpful unless you were deficient, which is uncommon in western diets.
https://www.nhs.uk/conditions/vitamins-and-minerals/vitamin-...
Vitamin B (thiamine) deficiency is also common among alcoholics. Lots of heavy drinkers out there. While obviously drinking less is the preferred solution, if they aren't willing to do that then supplements can reduce the harm.
https://adf.org.au/insights/alcohol-related-thiamine-deficie...
Before you go all in on the supplements (a) get measured for vitamin D levels first and (b) if you're anywhere in the ballpark of replete (you probably are) then make an effort to get outside, often, and without sunscreen. To the extent you don't get burned of course.
https://www.scientificamerican.com/article/soil-depletion-an...
If you don't believe food is sweeter and less nutritious, you're firing a shot at many-billion-dollar industries that have been earnestly been trying to optimize the above for all that time.
It's not a pleasant thing to believe, but its hard to refute.
IIRC, You should be able to do your own deep dives here:
https://fdc.nal.usda.gov/food-search?type=SR%20Legacy&query=
The food industry, like any other industry, focuses on numbers. Consumer spending favors new varieties of fruit with sweeter taste (e.g., increased glucose/fructose content). This process has led to our current comical situation where fruit, which is perceived as natural, has become unfit for consumption by animals.
>Fruits have gotten too sweet for some animals and zookeepers have had to find alternative foods.
https://weather.com/news/news/2018-10-03-fruit-so-sweet-zoo-...
Refute what? There still hasn't been any evidence provided for this claim.
Now a Granny Smith apple here may be different to the Granny Smith apple I used to eat but this is just to illustrate that I am not comparing two different kinds of apples.
I remember eating strawberries directly from the plant, and they were sweet. However, my aunt would serve the same strawberries with sugar as an afternoon snack.
It's practically the definition of FUD (fear, uncertainty, doubt). Based on no evidence "I think there's a danger because it's feels like there's a danger!"
You're saying "discount science based not on facts, but on the form in which such science is published" which is utterly unscientific
https://www.youtube.com/watch?v=iZ4p1bCsUio
"When Predator Becomes Prey: Will Dr Layne Norton Choose Humility or Humiliation? by Nick Norwitz"
YMMV
> A substantial increase in LDL cholesterol is likely for individuals with low but not high BMI with consumption of an LCD, findings that may help guide individualized nutritional management of cardiovascular disease risk. As carbohydrate restriction tends to improve other lipid and nonlipid risk factors, the clinical significance of isolated LDL cholesterol elevation in this context warrants investigation.
"warrants investigation"??? Come back when you have hard outcomes, i.e. reduced MACE. His meta-analysis of RCTs concludes that some people on keto have increased LDL! Norwitz admits in another video: "No, I'm not going to say that high ApoB is fine... ApoB is necessary but not sufficient [to cause ASCVD]" https://youtu.be/270ZyfSGLkE?t=484
So, what "humiliation"? If high ApoB (synonymous with LDL for our purposes) is bad, why would you go on a diet that causes it?
Layne has a large lay audience, and he has to stick to his main message: that w/r/t diet, calories are all that matter. Lowcarb/lowfat/vegan/whatever is fine. Platforming someone who's obsessed with LMHR is going to be too much biochemistry for Layne's audience. And for an effect that's relevant to perhaps only 2% of people? Low-carb advocates have their own YouTube channels; there's no reason Layne, as a center-aisle scientist, needs to engage.
Until the LMHR has been shown to have reduced MACE, which Norwitz admits we don't have evidence for https://www.youtube.com/watch?v=gxRLRYEQaEs&t=971s I don't see the point of Layne platforming him to just talk about biochemistry and confuse people.
Every week a new thing contradicts last week’s thing.
https://www.bbc.co.uk/news/articles/c0rwz5xkrg8o
To me it casts any discussion of nutrition on his podcast in a somewhat different, less than neutral light.
And then there's the further research you can do:
https://sciencebasedmedicine.org/ketogenic-diets-for-cancer-...
I dunno. I don't know enough to evaluate this in precise detail. But I do know enough to feel cynicism about extraordinary claims.
HFCS is 42-55% fructose whereas table sugar (sucrose) is ... 50-50 glucose to fructose. You will still get roughly the same total exposure to fructose (maybe even more) by switching to table sugar.
The only difference is that sucrose has to be broken down into glucose and fructose by sucrase, so the exposure is somewhat smoother instead of hitting you all at once, although humans have more than enough sucrase to make it a pretty quick process.
> Dates are often referenced as a good fruit option
fyi, 100gr of dried dates it like 3 to 4 times the average amount of sugar recommended per day. Just 2 medjool dates and you hit your daily sugar recommendation.
At the end of the day your body will have to process the stuff you ingest, if it comes with fibers the digestion will be slower, but if you eat too much of X Y Z day after day it's just a matter of time before your body gives up
[1]: https://edition.cnn.com/2014/01/15/world/europe/uk-zoo-monke...
That's the same as that "Serving Size" trick on nutrition information guides where the "serving size" is 5 potato chips instead of the entire bag.
There are Cherries along with every type of fruit you could want at Costco today and it's December.
Something I read recently was about eunuchs living something like 25% longer than intact counterparts. However, the data was limited (15 each of eunuchs and intact as I recall). There were very few confounding factors, however. Really interesting stuff.
Are there any culture that fast in a way that would matter here ? Most of fasting traditions are mostly performative. The average joe probably fasted more by default a few thousand years ago than most people do now
But sadly it's true of many YouTube podcasts today.
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.
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 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.
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.
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.
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.
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.
Oh, and at least in my case, it's not related to cholesterol or diabetes. I'm fine there. {shrug}
Corn syrup is a red herring.
"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.
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.
(Of course there’s no end of it on the Internets, but as part of heathcare it was absent)
Eating a healthy, plant-forward diet while minimizing alcohol and red meat might give us most of the benefit we can squeeze out of diet for cancer risk reduction.
could you provide the evidence that convinced you that red meat is detrimental to health?
This has been debunked so often, yet people really want to believe that food diet can cure everything!
For example, there is a good trial running now on ketogenic diet in glioblastoma patients, NCT05708352, I think with a NIH grant and maybe the NCI as well. Here is a video about it: https://www.youtube.com/watch?v=W31kR0MzyRA
Food and nutrition is a big business though.
Even the more educated members of family believe this.
I think doctors don't even bother because they assume people already do as much as they're willing to do, the problem is that the interests of capitalism are diametrically opposed to your well being so most people start with quite a disadvantage, just look at supermarkets: the alcohol, candies, coke, cakes aisles are all bigger than the healthy food aisle, together they're like 80% of the building
I've heard exactly the opposite from any number of people: that if you're overweight at all, many doctors will tell "lose weight and exercise" and then usher you out the door, rather than pay attention to the specifics of your medical problems - sometimes missing serious issues as a result.
There is a particular type of kidney disease called Polycystic Kidney disease which is genetic. Essentially cysts grow all over your kidneys, they swell up, and eventually fail (usually over many years). There is emerging research that glucose contributes to the growth of these cysts and early research suggests ketogenic diet can have a measurable impact on the growth of these cysts and improve kidney function.
A bit of a red herring, but still interesting.
https://www.nature.com/articles/s42255-024-01166-w
>> Most cancer cells rapidly consume glucose, which is severely reduced in the nutrient-scarce tumour microenvironment. In CRISPR-based genetic screens to identify metabolic pathways influenced by glucose restriction, we find that tumour-relevant glucose concentrations (low glucose) protect cancer cells from inhibition of de novo pyrimidine biosynthesis, a pathway that is frequently targeted by chemotherapy.
No diet has been conclusively shown to slow or stop cancer. I guarantee cancer cells can mutate to survive a keto diet.
Sugar is not safe, even though it is ubiquitous.
For many reasons avoiding meat seems reasonable, too. I used to be full vegetarian, for years, and then eventually re-added salmon and sardines.
It's a tiny step to full-on vegetarian keto, which is as good for you as full-on fasting is, I think.
I don't eat breakfast, veggie omelette for lunch (sautee some mushrooms and zuccini, or broccoli, perhaps, crack some eggs in once they cook down, give lots of olive oil and a side of something like kimchi, cabbage, or a pickle.
Usually eat whatever I want for dinner, including icecream, sometimes, but I spend most of the day in a low-sugar state of being, and if I 'clean up' my dinner(s) it's easy to eat a zero-added-sugar, extremely-low-carb, no-animal-protein, extremely-satiating form of food intake.
I really like it for me, and when I cook any of my foods, either when trying to be 'keto' or adding things like sweet potato, banana bread, ice cream, pizza, whatever, it's always well-received and considered delicious.
Also see Thomas Seyfried's work on ketogenic diets for cancer https://www.bc.edu/bc-web/bcnews/science-tech-and-health/bio...
He had a rare form of pancreatic cancer that grows from the tip of the pancreas and can sometimes be snipped out without consequence early enough that it doesn't spread.
He presumably freaked out about it all nevertheless (because it's terrifying), avoided surgery for too long and ended up having a Whipple procedure, which is fucking brutal.
But there's still a pretty good chance he would have had early surgery and still ended up needing a Whipple procedure and still have passed away on roughly the same timescale. Because pancreatic cancer is a stealthy thing, and the Whipple procedure comes with its own frightening future.
It's really sad he freaked out, it's really sad he didn't listen. But it's not that unusual. He's far from unique in making irrational decisions in the face of terrifying diagnoses. Should it have been a slam dunk decision? Yeah. Of course. But there we are.
https://pubmed.ncbi.nlm.nih.gov/16172215/
I mean... in terms of our scientific understanding at this point, sporadic pancreatic cancer just comes from nowhere. We don't know why. In the case of the parent I lost to it, it could have been triggered by a response to inflammation from previous surgery. It seems plausible. But nobody knows.
I just think people snarking or factoiding about Steve Jobs' panicked response to an awful disease comes across as projection of other judgements more than anything else. He was a complicated, self-reliant person who made a bad decision when he was scared. And it probably (but by no means certainly) cost him a few years of health. And now he is gone. And it's still sad for the people who lost him and for the wider world.
I didn't mean to dunk on Steve Jobs, but I'm sure even he would agree he had an eccentric and extremist personality and the bit about fruitarianism seems very relevant esp with happenings like [Ashton Kutcher being hospitalized when he tried to mimick it](https://www.theguardian.com/film/2013/jan/28/ashton-kutcher-...)
relevant quote:
> "First of all, the fruitarian diet can lead to, like, severe issues," Kutcher told USA Today. "I went to the hospital like two days before we started shooting the movie. I was like doubled over in pain. My pancreas levels were completely out of whack. It was really terrifying … considering everything."
on the other hand, I wonder what kind of steve jobs would the world have had, had he survived.
would he have pushed cancer research further, somehow? maybe by getting involved and providing funding and technology, maybe novel technology, for cancer research? or would he have gone full-cynical and focused on something else entirely?
we'll never know, for sure.
Jobs' fruitarianism meant he didn't eat eggs, meat, dairy, or other sources of selenium. Fruit doesn't contain selenium. One of Selenium deficiency's side effects, well established in the literature: pancreatic cancer.
Pancreatic cancer will fuck you up pretty much no matter what you do. I think it literally is the cancer with the smallest survival rate
That is true – and probably didn't help. But his case is a poor example since he delayed treatment for months.
EDIT: Also, actual fruits are probably not an issue. It's difficult to eat too much fruit, unless in juice form... which he did.
Though obviously "stop eating everything that gives you cancer" is also a good start, and you can definitely eat processed garbage even on keto.
It brought up a question that I'm hoping someone in this field could answer: Does it make sense to speed up cancer cell replication while providing chemo drugs?
It seems like this would result in greater discrimination between fast-replicating cells (cancer) and normal cells. In turn, this would allow faster chemo treatments, or less collateral damage.
Nonetheless this is a take from someone who has limited scientific knowledge, so I'm curious to see responses on this question!
Without knowing this, it doesn’t make any sense to assume that there is anything inherently bad about fructose, at least other than the mechanistic arguments mentioned in the article (which are weak if not backed up by empirical evidence)
Another fun fact: The "H" in HFCS stems from the fact just plain "corn syrup" is defined as 0% fructose. Fast food restaurants push the percentage to 58%+ fructose to turbocharge the sweetest taste in their sodas.
Maybe we have a reliable nutrition guide after all!
I suspect it's because diets like keto say it's OK to eat loads of meat and basically don't require any sacrifice. Fuck the environment and fuck other animals right bros?!