Intermittent fasting correlated with increased risk of cardiovascular disease | Hacker News Reader

Intermittent fasting correlated with increased risk of cardiovascular disease

bbc.com

https://www.sciencedirect.com/science/article/abs/pii/S18714...

Survey took 15 years, and 19,831 participants. Median follow-up was 8.1 years. Further research is required.

Methods

Adult participants who reported usual intake from two valid 24-h dietary recalls were included from the National Health and Nutrition Examination Survey in 2003–2018 (n = 19,831). Mortality status as of December 2019 was obtained through linkage to the National Death Index. Average eating duration was categorized as <8, 8–<10, 10–<12, 12–14 h (mean duration), >14–16, and >16 h. Multivariable-adjusted hazard ratios (HRs) were derived.

Results

During a median follow-up of 8.1 years, compared with eating duration of 12–14 h, eating duration <8 h was robustly associated with higher cardiovascular mortality (HR, 2.35 [95 % CI, 1.39–3.98]), but not with all-cause and cancer mortality. The positive association with cardiovascular mortality remained consistent across 8 subgroups stratified by race/ethnicity, socioeconomic factors, and smoking status, and survived 14 sensitivity analyses. However, the association with all-cause mortality did not survive many sensitivity analyses.

Conclusions

Although a positive association was observed between eating duration <8 h and cardiovascular mortality, further research is required to understand whether this risk is attributed to the short eating duration itself or residual confounding resulting from its contributing factors.

15 years ago, was intermittent fasting even a thing back then? I wonder how many of the people eating within an 8 hour window didn't do it because of a diet, but instead because of an eating disorder or some other disease.

Anecdotally, yes, i was doing it and there was a bunch of stuff online

Yours should be the top-most comment.

This is another reminder that, in the short term, a lot of research about health amounts to very little signal because the confounding factors are so varied.

We can, of course, learn a lot about health very quickly, but much of the reporting is sensationalised nonsense.

for example, folks who are doing if are probably overweight and at higher risk than the baseline already. I didn’t see this controlled anywhere

Maybe. I did IF for 6 years simply for the healthy aging claims, despite being fairly active and fit. Is it really a weight loss thing?

Some people seem to not just survive, but actually thrive on terrible, junk food diets, like the current president, or Warren Buffett (who eats ice cream and mcdonald's for breakfast and 2 liters of cherry coke every day, and is still alive at 95) https://www.businessinsider.com/warren-buffett-diet-2017-10

Diet really does seem to be one of those highly individualistic things, and I'm guessing humanity is in an evolutionary transition from paleolithic type diets to mcdonalds 3 times day, with different people having the genes to thrive on different things. You just have to see what works for you.

Picking anecdotal exceptions doesn't indicate broad genetic differences that allow people to "thrive on junk".

Everyone has heard of someone who smoked and drank and lived to a hundred. That doesn't mean smoking and drinking aren't harmful for health; Infact overwhelming evidence clearly shows their harm. Same goes for unhealthy food, and we broadly see the impact statistically as well as viscerally.

My anecdotal experience is there are no long term full time cigarette smokers over the age of 70 because they all died.

https://news.ycombinator.com/item?id=45081132

... Are you giving anecdotal evidence against the anecdotal evidence the other person gave?

Fran Lebowitz, avid cigarette smoker, 74 and counting.

https://en.wikipedia.org/wiki/Fran_Lebowitz

https://www.youtube.com/watch?v=aGcG7e03Nts

Yes, I did see her speak earlier in the year. You're right. Some are just built different.

My anecdotal experience is they were all over 70 but not over 80 -- chain smokers who started when they were children. I'm curious if anyone here knows any in their 80s or 90s.

My grandfather from the south of italy. He died at 85, used to smoke two packs a day until about three days before dying (he wasn't allowed to smoke in the hospital). He did not die from any form of cancer, he died for an intestinal blockage. I don't remember the details, it's been many years ago. From what he told me he started around age 8, stealing his father's tobacco.

The thing is, these stories rarely show the full picture (and they hardly can).

For example: my grandfather was very active for an old person, he kept working in his coutryside until the age of 78-79. That meant a lot of moving around, lifting large buckets of fruit in spring and summer or huge sacks of olives in autumn and winter. At age 75 he was probably way more active than the average user of this forum. He wasn't "fit" by modern beauty standards, but nonetheless he was "functionally" fit.

As far as I know, he started working in the countryside when he lost his father around age 13 (society was different back then) to support his family (his mother and his younger sister).

Btw he still developed senile dementia roughly around the time he stopped working in the countryside.

Smoking alone is a risk factor (and a huge one) but that factor usually has to be put into context.

EDIT Just to disambiguate: I'm not defending smoking, in any way. My main point is that "full picture" is often missing from the "they smoked and lived" stories.

Haha, my uncle lived to 94 smoking like it was a cure for cancer, and I've seen a picture of him filling a sprayer with 2,4D with no PPE and a smoke hanging out of his mouth.

Everyone has heard of someone who smoked and drank and lived to a hundred

It's interesting that the oldest known human to have lived (122!) smoked too: https://en.wikipedia.org/wiki/Jeanne_Calment

Calment continued smoking in her elderly years until she was 117

But I'd say she is definitely an extreme genetic outlier, and would not bet that she could've lived longer had she not smoked.

(Disclaimer: non-smoker and no interest in doing so either, for other reasons.)

> Disclaimer: non-smoker and no interest in doing so either, for other reasons

A better word would be "irrelevant"

Worth noting that there is some controversy about whether Jeanne Calment was actually 122, or it was a case of her daughter Yvonne assuming her identity to commit pension fraud...

This is apparently endemic in the so-called "blue zones" where folks routinely live well past 100 on paper, but its thought that many folks are exploiting poor record keeping in the past to keep drawing their pension checks

If it was her daughter, she still lived to 99, which is above average and even more so for a regular smoker.

- But you won’t know what works for you before you had your first heart attack.

- If your claim was true, shouldn’t the data be more flat and not show an increase in mortality? Or do you suggest that only few people have these genes? Survivorship bias probably has the greater effect here.

- Buffet and Trump are probably closely monitored by doctors and get way better treatments (although my grand dad wasn’t closely monitored and survived to 91 on 2 liters of coke, too, but had quite a few ailments)

My dad is 81 years old and if you see his diet and sleeping habits, you’d think this man would be morbidly obese and unhealthy. He eats deep fried foods almost every second day, has a massive sweet tooth, sleeps at 2-3AM, almost never works out

And yet he is the healthiest 81 year old I’ve ever seen. Amazing blood work, no blood pressure or cardiovascular issues, and is mentally 100% the same as he was 20 years ago.

I really don’t think conventional medical science can explain it

Not quite to the level of explain, but what one only needs is an excellent liver. This is mostly a matter of yet unknown genetics. We know a few variants where different variants of classes of lipids are made reducing the risk for cardiovascular disease...

If you have a bad one like myself, you go decent diet and still have metabolic syndrome by 20. (No diabetes at least. Yet.)

My dad has never touched a drop of alcohol. That might have something to do with it too

Those are outliers. It doesn't mean that these foods are healthy for the average person.

There are documented cases of people living well into their 80s while having smoked cigarettes since their teens. Same thing. It doesn't invalidate the millions of deaths each year that are directly caused by tobacco.

Also, wealth plays a larger role in living longer than genetics. It gives access to the best medicine and physicians money can buy, which are not accessible to the average person.

Please tell us what FDA approved medications Buffett has been on for the past 70 years that aren't available to the rest of us and have allowed him to cope with ice cream for breakfast every morning.

Being wealthy and powerful doesn't constrain you to the health care system of a single country. It also allows you to be at the top of any priority lists for treatments and interventions.

And, as a sibling comment mentions, marketing plays a big role with these individuals, so it's impossible to ascertain the truth of their claims.

When people discuss the impacts of wealth on health, they're almost always talking about assessments and procedures, not prescriptions.

Evolution doesn't work over a span of few generations. If humans are evolving to adapt to the modern weetern diet then we won't see that for a very very very long time.

You're just cherry picking examples while ignoring a mountain of literature that shows exactly the opposite of what you're saying.

> evolution doesn't work over a span of a few generations.

Yes it can

> Over the past two decades, it has become clear that evolutionary change can be fast enough to be observed in present-day populations (Hendry and Kinnison 1999; Kinnison and Hendry 2001; Hendry et al. 2008; Gingerich 2009) and that it can directly affect the dynamics of populations and communities (Hairston et al. 2005; Saccheri and Hanski 2006; Kinnison and Hairston 2007; Pelletier et al. 2009). Much recent interest has focused on the possibility that so-called rapid or contemporary evolution leads to ‘evolutionary rescue’, whereby threatened populations avoid extinction by adapting to an altered environment (Barrett and Hendry 2012; Gonzalez et al. 2013).

https://pmc.ncbi.nlm.nih.gov/articles/PMC3894905/

It'd be surprising if that applies in this context. In the case of the individuals OP mentions, their parents would not have been exposed to ultra processed food (or barely, perhaps only after they've reproduced), so ehatever gens they passed on would not have been adapted. There's simply not enough generations in this case. Especially not for such significant changes.

In any case, it's moot as by and large the westeren diet is not good for the population, exceptions are simply that.

My great grandparents in the US were eating diets of ultra processed foods. Soda Shopes, hot dogs, sausages, hamburgers, Spam, boxed spaghetti, hamburger helper, Jello molds with canned fruit in them, etc.

My great grandfather in particular used to smoke a box of King Edward cigars a week, and lived mostly on a diet of plain bologna sandwiches on plain white bread, and candy corn.

Re trump and buffett, we have no idea what they actually eat, unless you are in contact with them or their chefs. That buffett says he drinks 2 litres of cherry coke everyday, should be taken with a large pinch of salt, given he is such a large shareholder in the company. This is marketing.

Right. Particularly Trump, who lives in a perpetual bubble of lies and disinformation.

Agreed. Buffett always just mentioned enjoying a single burger and can of Coke a day.

I have no idea about the burger, but for the Coke I don't think that's true.

Here's one of many sources saying that he drinks 5 cans a day:

https://www.businessinsider.com/warren-buffett-diet-2017-10

What's your source for him always mentioning the single can amount?

His biography.

Not that individualistic. We have tables giving upper and lower limits for around 26 nutrients for daily intake. These tables are published by dozens of countries which mostly did their own research over decades. The tables are pretty much consistent with very little variation. Grok offers a rough estimate of between 10 and 50 million subjects used to determine these values. When you say 'you just have to see what works for you' that’s fine if the ‘what’ is a container (food) that provides content (nutrients) within the limits that extensive research has found to work. With a few very odd exceptions our biochemistry is consistent.

> to not just survive, but actually thrive on terrible, junk food diets, like the current president

What are your indicators of "thriving"???

I don't buy that eating McDonalds or ice cream or pop even regularly is inherently bad for you. People don't call a loaf of bread junk food, but is mostly just starches and sugars. A McDonalds burger may have a lot of fat and calories, but it still has beef in it which has lots of nutrients. Pop may be mostly just calories from sugar, but nobody is drinking pop as their only source of food and if your other foods are nutrient dense, I don't see much of a difference.

https://www.sciencedirect.com/science/article/pii/S277241662...

Kind of disappointing to see this at the top.

Not only have you cherry picked anecdotes to support this, but you don’t have a counter factual, e.g. maybe someone who survives until 95 on junk food would have lived until 105 on healthy food.

This is a good point, its because of a mix of gut bacteria and the genetic composition of individuals - but the ultra good ones like that example are few and far between

It seems like there's a very plausible mechanism for reverse causation here. If you're already having health problems, you are more likely to follow a dietary pattern that is said to promote health. That this translates to a correlation to heightened cardiovascular risk seems unsurprising.

Yes, and it could be that intermittent fasting with metabolic syndrome is cardiotoxic but intermittent fasting without is cardioprotective.

Not saying they are wrong, but my feeling is that selection effects probably dwarf any causal effects here. You don’t need much skew in the health distribution of people who are drawn to an intervention like this to get this kind of correlation and effect size.

I have not read the paper, but how did they differentiate between people eating non-breakfast food in the morning and people skipping breakfast?

From the quote below, it seems their method all but precise

> To understand their eating habits, participants were asked on two separate days - about two weeks apart - to recall everything they ate and drank. From these "dietary recalls", scientists estimated each person's average eating window and treated it as representative of their long-term routine.

Same! I’m firmly starting to believe these studies are being conducted to confuse the public even further with regard to eating. The media have been focussed on eating/public health for a couple of decades now and during that period all I’ve witnessed is a rapid and sharp decline in general health and eating habits and increasing pointless discussion about it all.

All the time, energy and confusion just starts to enrage me now. Does the time of day you eat really matter? Maybe… but is there really any major difference in poisoning yourself before noon or after? If there is, is it worth discussing? Is it worth studying?

It’s really super simple - you are what you eat. If you aren’t, what are you?

If you put stuff into you that’s one step away from poison or toxic waste, don’t be surprised when the body reacts the way it does and eventually dies early. I’m talking about anything processed/manufactured (99+%) that comes from a factory.

If you want to live a long and healthy life, it’s no more difficult than just eating as much fresh and varied, un-poisoned fruits & vegetables as you like. That’s it. This advice can’t prop up billion dollar food, advertising, media & pharma industries though.

People think this is hard to follow as well because they are addicted to everything in processed food, lack time and their body is already in a constant high state of stress.

As soon as the diet changes to one of health & life, stress rapidly reduces, health improves, taste buds alter and suddenly within a short time, all that stuff you used to eat, tastes like the actual crap it really is.

Most of what you just said makes sense to me, and I believe you are right to draw the attention toward the elephant in the room: quality and variety of ingredients.

The reason why I'm writting this reply is this bit:

> I’m talking about anything processed/manufactured (99+%) that comes from a factory.

No. If we want a chance of survival we have to stop assosiating "factory" and "industry" to "bad". First, despite some of the bad press the food industry regularly receive is probably well deserved, overall food safety out of a factory is very good; much better than anything we ever had in history, and especially safer (if not tastier) than the equivalent homegrown product.

Highly processed food is a problem, be it out of a factory or fried by grandma.

I've worked a bit in this industry, and I can attest that even the less regulated industry will self-regulate periodic biological tests and put in place germ control policies that are much stricter than anything your local farmer will ever be able to do; just because of economy of scale.

And the same goes for the environment: If we don't want to exhaust natural resources we have to resort to industry economy of scales. The quantity of energy and water that would be required to grow tomatoes in our gardens is stupidly wasteful compared to industrial norms. The quantity of detergeant and water needed to clean cooking pots for family-scale cooking is enormous compared to the quantity needed to clean tanks used in the industry.

I feel stupid to have to state the obvious but I'm starting to get really afraid of this trend that associates small scale with better safety, better variety and better economy of resources while the complete oposite is true.

I thought we gave up on IF a couple years ago when we determined it didn't help with weight and caused loss of muscle?

For me, the only effect of IF was insulin sensitivity so high I would fight passing out after a moderately carb rich dinner. I hated it and found no benefit.

> They found the elevated cardiovascular risk was consistent across socioeconomic groups, and strongest among smokers and people with diabetes or existing heart disease - suggesting they should be especially cautious about long-term, narrow eating windows. The link held even after adjusting for diet quality, meal and snack frequency, and other lifestyle factors, researchers found.

Smoking makes it easier to skip meals, which is part of why people gain weight when they quit. Smokers who more likely only ate in 8 hour windows may just be heavier smokers than those who ate across 14 hour windows if there is a dose response relationship to the meal skipping.

Diabetes also can make meals at certain times of day make you feel sick and more likely to be skipped (more examples beyond this, but look up dawn phenomenon with diabetes).

They say all cause mortality is not much different blbut those two subgroups had the higher mortality compare with same subgroup that ate over a longer period. But it could just be heavier smokers skipping meals and more advanced diabetes case sufferers skipping breakfast unless controlled for separately (smoking amount and dawn phenomenon)

So just a simple question - if I eat dinner at 6, then dont eat breakfast til 9 or 10 the next morning after waking up.. 6pm to 10am is 16 hours. What is so extreme about that? I do that most days without even thinking about it.

I feel no hunger after dinner, overnight or in the morning when I wake up. What exactly am I doing wrong according to this study? Im NOT hungry, therefor I dont eat. Later in the morning I feel hunger so I eat. 16-18 hours passes and I feel totally normal before my first food of the day. Do people really think this is actually an abnormally long time to not eat anything?

Part of it depends on your basal metabolic rate and your activity level, but you're also sleeping during that period.

Now if you were awake for 16 hours and hadn't eaten, that's closer to my original understanding of intermittent fasting.

The quality of studies seems so poor it almost seems like the people conducting them don't even care about their quality, but wherever gets funding and keeps the bosses happy.

Basically the car salespeople of academia.

I'd suggest that only people who are already overweight will be trying intermittent fasting. Needs a study with randomly selected people who are put into two groups - overweight and lean, then half of each group start intermittent fasting.

Also, since when is just restricting eating to certain hours of the day 'fasting'?

My experience: I was overweight, 95 Kg. Two years of not getting anywhere with attempting to reduce intake, due to living alone, which makes cooking small meals difficult. Heard of "36 hour fasting", and decided to try it. Except I felt '36 hours' is half-arsed. So to simplify I just do 48 hour fasts. Turns out it's very easy, and I can reliably drop a couple more kilos anytime I choose to do another fast or two. Currently down to 84 Kg. Will be 83 after the current one probably. Once I'm at 80kg, I'll decide whether to continue down to 75 or so.

I also asked that question in another comment. If i eat dinner at 6pm, Im not hungry the rest of the day, overnight nor in the morning when I wake up. Around 10 or 11 I start to feel hunger that doesnt go away - So i eat. 16-18 hours has passed but I was never counting or thinking about it... Is that really fasting or denying myself food? Is it considered fasting to not constantly snack and crave processed foods?

To a certain extent I think it depends your level of activity. If I'm sedentary and I eat a big dinner I usually won't feel hungry at least until 3pm the next day and sometimes it can be full 24h before I really feel hunger kick in again.

It's been that way as long as I can remember but I try to make sure I eat something in the morning anyway because I noticed that I function better that way (duh!)

I think avoiding sugar makes a significant difference. I love sweet treats but I've eliminated the vast majority of sugar in foods and drinks that I consume on a daily basis. Occasionally I'll start eating cereal for breakfast and I notice that it makes me hungry more often and it completely messes with my energy levels, so I stop.

>> I'd suggest that only people who are already overweight will be trying intermittent fasting. Needs a study with randomly selected people who are put into two groups - overweight and lean, then half of each group start intermittent fasting.

Came here to comment on this. There is no mention in the article (and I can't access the paywalled study) that the researchers controlled for BMI so there is no way to tell whether the participants of the study who were more likely to have cardiovascular problems were also the ones who were expected to have them because of overweight conditions.

I'm not advocating for intermittent fasting, to be clear. I tried it a while ago and it didn't do anything (I lost a couple of kg then got them back again when the seasons turned) but the study seems shoddy and uninformative. Or I'm just in reviewer number two mode.

Did they account for who was overweight? Cause it doesn't sound like it.

I find it interesting that there is this sentiment that humans have forgotten to listen to their bodies and at the same time there is this other sentiment that you shouldn't trust your body.

What I mean: I have Morbus Meulengracht and my metabolism definitely works differently than that of other people.

I follow my body. If I have hunger at 10pm, I eat something...

All my blood values, apart from Bilirubin (of course) and Cholesterin are absolutely superb

"Eating duration <8 h was linked to 135 % higher cardiovascular mortality, but was not associated with all-cause and cancer mortality."

...

"Although a positive association was observed between eating duration <8 h and cardiovascular mortality, further research is required to understand whether this risk is attributed to the short eating duration itself or residual confounding resulting from its contributing factors."

I think I've seen a preprint of this study discussed a little while back. What some experts(?) were suggesting is to widen the window to something like 10 or 12 hours.

Was the preprint the full text?

I can't find a full text version, and I'm really interested to see whether they calculated the moderator of being overweight/obese, as that seems to me to be the most likely explanation for a correlation between IF and higher cardiovascular disease mortality.

It's not listed in their list of confounders they've corrected for, so maybe I should assume they haven't done that? If they have, maybe I'll stop with IF, otherwise I'm not sure what the results really show.

For what it's worth, it always felt unhealthy when I tried due to increased stress levels

<8h feeding window, but “normal” eating habits are usually around 12hr feeding window. I find it very hard to believe that simply waiting an extra 4 hours to eat has any appreciable impact on health. Our bodies aren’t that fragile.

The food and drugs industry wants you fat.

Correlation vs Causation.

What isn't IF correlated to at this point?

luckly junk food will keep us healthy /s

Do yourself a favor, and just take GLP1s instead (after talking to your health care professional). The research on the effects is plentiful, they're incredibly effective, and next year by next year you'll have very effective FDA approved (for weight loss) oral GLP1s to take.

Losing weight is almost solved at this point, I'd post links but at this point the substack I run is heavily paywalled -- the research is out there and not hard to find with a quick search.

My wife started taking GLP1 2 1/2 years ago. She had to stop because it made her throw up every morning.

She hasn't been on it for 2 years.

She still throws up every morning.

(Yes, they've gone into her digestive tract multiple times with cameras. It still won't stop. Changes in diet, sleep, etc have had no impact. Etc.)

Maybe it's not for everyone.

That sounds like a terrible experience, sorry you and the wife went through that and somehow the negative side effects STILL persist. This is honestly the first case I’ve ever heard of such an adverse effect.

GLP1s are certainly not for everyone, and if she had that reaction on a starting dosage then it certainly is obvious stopping was the way to go.

That said, for the vast majority of people though, GLP1s are likely going to the key to living longer and carrying less weight (including into old age). At this point, the research is behind the drugs being useful for the vast majority of the population, and the literal millions of people taking these drugs do not seem to be running into such horrific side effects, especially ones that continue after stopping the drugs.

Would you mind sharing which GLP1 she was on? This actually sounds like something that should be more widely known. Throwing up forever is quite a crippling side effect, and since GLP1s are more recently considered primarily brain drugs, I wonder if it triggered a persistent chemical imbalance.

There are multiple class actions consolidating.

https://www.lawsuit-information-center.com/ozempic-gastropar...

Yeah weirdly enough they’re only taking NAION and gastroparesis cases. Do you know by any chance why that is?

The NAION link is tenuous (research was inconclusive, I have written about this before[0]) and gastroparesis is a known side effect.

This was a great chance to learn the name of the vomiting symptom though — will be looking more into “cyclic vomiting syndrome”

[0]: https://glp1.guide/content/glp1s-and-the-link-to-blinding-di...

> only taking NAION and gastroparesis case. Do you know why by any chance why that is?

No, sorry.

Yes, CVS. Not the brand :)

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