Note that this is probably not what you are thinking (low-carb, very-low carb or even keto diets are good for your healthspan).
The lowest quintile in this study were consuming 46,4% of kcal from carbs (that's about 230 gram of carbs for a 2000 kcal total intake). Not even close to low carb by today's standard in the health blogosphere.
The authors make this explicit in the discussion section:
>>> However, the absence of association between low carbohydrate intake (eg, <50% of energy) and health outcomes does not provide support for very low carbohydrate diets. Importantly, a certain amount of carbohydrate is necessary to meet short-term energy demands during physical activity and so moderate intakes (eg, 50–55% of energy) are likely to be more appropriate than either very high or very low carbohydrate intakes.
One certainly can fuel activity with carbohydrates, but a fat-adapted person should have no trouble with physical activity on a (very) low carbohydrate diet. Interestingly, a fat-adapted athlete can still use carbohydrates for supplemental fuel before, during, or immediately following extreme exertion (no adaptation is required for short-term use of carbohydrates).
> Importantly, a certain amount of carbohydrate is necessary to meet short-term energy demands during physical activity [...]
Why would they make such a claim? Anyone who has done keto and worked out has probably had the experience of doing quite a lot of physical activity while having had no carbohydrate intake at all for half a day before, or more.
As someone who has been on a low-carb diet for 3 years, on and off, I definitely don't notice any difference in performance, mood or productivity while on a low-carb diet. Too many people (esp. those in a desk job) over estimate their physical activity levels and think they need more carbs.
Sure, if you're an athlete, all this doesn't apply to you. But, for the vast majority (who in the present day) lead highly sedentary lifestyles, it's about time we encourage them to get off carbs as much as possible.
I think the assumption there is very-low carb (as a macro-nutrient, not "healthy" v "unhealthy") can be better if _lower_ carb demonstrates improved outcomes... ?
That is about what I have been eating naturally (~150-250g carbs daily, pretty much from oats, potatoes, sweet potatoes, dairy, and 1-2 servings of fruit per day).
Be careful making any changes to your diet based on these "findings". The healthiest populations on the planet eat plenty of carbs, but not refined sugars.
Even without the data quality issues, there are obvious uncontrolled confounding factors. I don't understand how a real scientist can title this study "Dietary Carbohydrates Impair . . ." when the finding is actually "Dietary Carbohydrates Are Associated With Impaired . . ." Clear evidence that statistical training (or perhaps just incentives) for scientists remains insufficient.
What's really surprising is how many people on here are like, "of course, ketogenic diets!" Where is all the skepticism that is so vividly on display when discussing the latest Google or Facebook product announcement?
I always wonder, when nutrition studies are usually so poorly designed and controlled, why people don't just look at the blue zone diets for nutrition guidance.
I'm not surprised to see this at the top of HN considering how many people seem to be fans of the Keto Diet. I am very excited for people who find something that works for them, but I would be very wary of a study like this if you are looking for confirmation for multiple reasons:
1. The study "did not analyze which specific source of carbohydrates (e.g., sugar/refined carbs versus whole-grain products) may contribute to the detrimental effects of carbs observed, especially since income and wealth do impact the quality of dietary choices significantly."
This is HUGE. Any study or person that attempts to label an entire macronutrient as "bad" or "evil" is not helping anyone understand the whole picture. The most nutritious foods in the world are carbs. Many of the least nutritious foods are also carbs. Not distinguishing the two gets us nowhere.
2. With this study and most high fat/keto diet studies as well, the timeline is not long enough to tell us about true "lifespan" impact. This one is over 7.4 years. I know it's more difficult to do 10, 20, 30 year studies, but until something can be correlated over those timespans, I would not bet everything on that diet for longevity. There are a handful of generational studies, and almost all have shown that "high carb" or more specifically "plant based" ARE good for longevity. Not saying high fat aren't good for longevity as well, but we have yet to really see examples yet.
3. As many who have tried Keto specifically will tell you (as some have mentioned in the comments), it is very difficult to maintain a ketogenic state. You have to be very disciplined, and this is made harder when you are a social person. This is a big problem when talking about diet and longevity. If it's not fairly easy to maintain, then it's not a feasible diet for longevity where the average person is concerned.
4. As someone else mentioned, the percentage of carbs that the studies participants were eating were not even close to the level required for a Keto Diet
I've read a lot of, often conflicting, dietry guidance. I have realised one very important thing: humans will very easily accept that something they enjoy is bad for them (see fat, sex etc.) So listening to what people say is bad for them is stupid.
Instead I have taken a simpler approach: I observe the lifestyles of people who are healthy and live a long time. I have observed that eating simply "good, old-fashioned" home cooked food is important. My grandmother lived into her 90s. Ate fat and carbs. Julia Child lived into her 90s. Ate fat and carbs. Edna Lewis lived into her 90s. Ate fat and carbs. I could go on. Just do what they did and you'll have as good a chance as any.
The problem is that simple home cooked food can't be commercialized. So all advice that gets published will be for something where you can buy a product.
Same for exercise. We already know how to exercise but there are always people who want to make money by repackaging it.
Selection bias is something worth avoiding in understanding health studies.
It’s quite likely that you know about these folks because they had the right genetics to be healthy outliers, and by extension, famous. It’s no different than saying I know x people who didn’t die of lung cancer due to smoking, which doesn’t change the implication that y% of smokers will always get lung cancer, we just haven’t figured out what fully constitutes your risk ( genetics etc)
I'm sorry - this is naive advice. Generalized, this would mean that we shouldn't innovate or develop anything new at all (if what's worked previously is the ONLY way it should work).
Especially, with something related to diet and nutrition, there is an ever evolving need to alter our habits with the way our lifestyles changed. The kind of life your grandmother led is vastly different than the way you do now.
Similarly, carbs were great when as a culture we embraced agriculture, started working the fields and were able to secure food supplies for emergencies and the next generation. Now, farm productivities have shot up, fewer of us are working directly on growing food and there's abundance of food choices all around. We no longer need the easy glucose that we needed earlier. So, it is important that we change our dietary choices if we want to lead healthier lives.
I’ve been living a ketogenic lifestyle for a few years now. I go in and out once and a while but seeing the “fat is bad” theory thrown out the window with research like this makes it easier to remain committed.
The trouble comes with the way society has been conditioned to have carbs with every meal. Like 90% of the food my peer group eats are surrounded in carbs. Even for a company-wide lunch in the office: the go-to is usually a couple dozen pizzas.
Once you’ve lived low carb for a long time you look at people in line at a coffee house grabbing a bagel and a milkshake and just feel bad for the crash they will have later.
I’m happy to see Keto becoming more and more socially known. Accessiblity around low carb options is getting better and better. My favorite will always be a protein style burger from In-N-Out though.
You hit the nail on the head for exactly why I couldn't stick with a ketogenic diet. It became too much of a burden on the people I was with to feed just me because everything they wanted was stuff like tacos, pizza, rice dishes, fried dishes, etc. I have an unresearched (by me) theory that the reason we have so many carb heavy diets is due to the fact that carbs are such cheap calories. They were good for surviving when we were poor but now we should move past them
But this research says nothing about such a strict and artificial diet over a long period of time. I wonder, do you know of any people who have eaten keto all their life and lived to an old age?
A few years does not prove a lifetime. If a million people ate your diet and lived X% longer than a similar set of people who didn't it might prove a useful stat. You might wind up dying of something not obvious today at 70 due to your diet, or not. No easy way to know. That's the problem of dietary knowledge.
totally agree. when there are no carbs around me - i have zero problems sticking to keto. whenever there's a party and some snacks - i'm in a danger zone unless i brought my own snacks in which case i'm a weirdo.
Reading through all the comments and this one stood out. I am currently a 'reluctant vegetarian' for health reasons of course (bad choices were made during my younger years and now I am so paying for it). However. In-N-Out would be allowed were I near one. I like to eat grass (grass like veggies). Cows eat grass. I will eat the cow that ate the grass at In-N-Out burger. /shrug. Sounds legit to me.
- I'd also have a 'healthy shake' there as well. I remember their adverts that mimic'd/mocked the shake diets and it still makes me chuckle.
Fat is bad for some people, though. How satiated someone is by carbs or protein tends to be pretty consistent, but fat is more variable between individuals. Some people are just predisposed to overeating fats.
Yep, it's surprising how hard it is to avoid. Compound that with sugar being in almost everything and it ends up being remarkably hard to find options that won't cause your blood sugar level to spike.
Do you have any recommended reading on your diet, and the potential problems of a modern milkshake-abundant one? I could just Google it but it's hard to cut through the noise/misinformation when researching diet stuff for the first time.
Mainly asking because my diet yesterday was a six pack of Kirin Ichiban beer, a double cheeseburger, and a large P. Terry's chocolate shake, and I felt fine and still had a very productive day. I want to know why I'm able to tolerate stuff like that, and how/if that armor might start falling off as I get older.
>The trouble comes with the way society has been conditioned to have carbs with every meal.
I am pretty sure that isn't conditioning. Eating a burger with no chips is just plain wrong, and the same the other way around as well. When I am eating rice and meat together, if I eat just meat, it doesn't taste good. It is so specific, that there is a specific amount of rice that has to go with the meat. Everyone knows this. That can't possibly be conditioning. People complain of "too little rice", "too much meat" etc. No one could have been conditioned so specifically.
> Next, a number of studies have evaluated the effects of specific macronutrients on lifespan, initially in S. cerevisiae (Lin et al., 2002), subsequently in C. elegans (Schulz et al., 2007 and follow-ups), and mice. Out of the latter, two studies in the previous issue of Cell Metabolism have studied this in mice starting at 12 months of age. In regards to the PURE study, most notably, the almost complete removal of carbohydrates (<1%) from the diet to generate a ketogenic diet extended lifespan compared to a high-carb diet. However, reconstituting only 10% of energy of the ketogenic diet by sugar abolished this effect (Roberts et al., 2017), suggesting that specifically sugar (rather than carbohydrates in general) has the most relevant effect on lifespan. Along this line, it is also interesting to note that when nutritive sugar content is kept constant, a different (and less extreme) high-carb diet exerts the best effects on murine lifespan. By contrast, a high-fat diet still containing the same amount of sugar, but no other carbs reduced lifespan slightly. Lastly, when combining high-fat and high-carb components from the two previous diets, the worst effect on lifespan was observed (Keipert et al., 2011). Moreover, lifespan extension in mice was also obtained when dietary protein was replaced by carbs, possibly independent of the total uptake in calories (Solon-Biet et al., 2014). Taken together, these studies suggest that dietary sugar may be one important, but not the only, nutritional factor in limiting healthspan in rodents, hence additional studies are definitely required to establish firm evidence in model organisms.
This section of the article does not correspond to the title. In fact it seemed all over the place, then goes on to conclude ‘maybe it’s refined sugars.’
Related; I saw on Hacker News awhile back a really great website that aggregates a lot of this health research and then gives summaries of, "What's the current known truth" based on all of the varying research. They then re-market that data as a service somehow. Anyone on here recall this by chance as I'm no longer able to locate it?
as I mentioned in my comment, any study that lumps together all of one macronutrient into one group and then attempts to reach conclusions based on that grouping has very little understanding of nutrition.
I’ve found eating out socially on keto a big challenge (carbs still look delicious) until I found a hack: unreasonably large portions of salad, covered in salt. Salt is fucking delicious. Add olive oil too if you feel like it.
I drown everything in olive oil. Good, European protected designation of origin (PDO), protected geographical indication (PGI), and traditional specialities guaranteed (TSG) type olive oils.
They're delicious. And you get full rather quickly. That feeling lasts.
And I'm fairly certain the plant fat is not what's making us jiggly
And yet many of the longest-lived populations on earth have diets rich in carbohydrates, like the Okinawans.
I hate associational studies like this which don't distinguish between types of carbohydrates (sugar vs starch) or other factors, like whether they were eating whole meals of natural foods or snacking on potato chips 24/7.
But at least they've finally noticed they were completely wrong about saturated fat for 80 years.
tl;dr Refined sugar contributes to getting fat, and an early grave. No shit, Sherlock. They conveniently left out any reference to fiber, or the exact sources of said carbohydrates. Sources matter tremendously due to fiber content and levels of refinement.
Stick to fibrous veggies, beans, nuts, some fruit (berries are best), and you'll be just fine eating carbs.
I'm not contesting the fact that ketogenic diets work for people. But this study is kinda bullshit since it's basically alluding to the worst kind of high GI refined carbs
>>> (1)The conversion of D-glucose into metabolic intermediates, namely glycolysis, can be inhibited by compounds like (the highly efficient but rather toxic) 2-deoxy-D-glucose or (the less efficient but completely harmless) D-glucosamine (GlcN). The latter is widely used to treat arthrosis with the questionable claim of inducing cartilage regeneration. Both compounds have been shown to extend C. elegans lifespan (Schulz et al., 2007, Weimer et al., 2014), while only GlcN extends lifespan in rodents (Weimer et al., 2014). Notably, GlcN uptake has been also associated with reduced mortality in a large human cohort (Bell et al., 2012).
So does this mean the glucosamine chondroitin pills I take for my joints will help reduce glucose conversion and extend my lifespan?
Can anyone provide a TLDR on what exactly the conclusion of this article is? My experience with a low-carb diet is quite similar to that of @whalesalad, and it remains much more effective than any other diet or a strict exercise regimen.
Dehghan et al. (2017)) found that carbohydrate intake was associated with increased total mortality. By contrast, any (saturated/monounsaturated/polyunsaturated) type of dietary fat reduced the likelihood of dying.
"Moreover, there was no link to cardiovascular events or related mortality, except for saturated fats, which were unexpectedly associated with a lower risk of stroke."
are you addicted to carbs, or are the critters living in your gut that get hangry when you starve them? more of a talking point because i dont have my head around it. my wife had me do a "die off" diet for several weeks of doing keto; i got super bloated, got a rash everywhere, and then all of a sudden felt skinny and good. ...then i binged and it was all normal again
[+] [-] fasteo|8 years ago|reply
The lowest quintile in this study were consuming 46,4% of kcal from carbs (that's about 230 gram of carbs for a 2000 kcal total intake). Not even close to low carb by today's standard in the health blogosphere.
The authors make this explicit in the discussion section:
>>> However, the absence of association between low carbohydrate intake (eg, <50% of energy) and health outcomes does not provide support for very low carbohydrate diets. Importantly, a certain amount of carbohydrate is necessary to meet short-term energy demands during physical activity and so moderate intakes (eg, 50–55% of energy) are likely to be more appropriate than either very high or very low carbohydrate intakes.
[+] [-] XFrequentist|8 years ago|reply
The missing concept (in the brief quote in your comment) might be "fat adaptation", which takes (in my experience) 2-4 weeks (details: http://www.artandscienceoflowcarb.com/the-art-and-science-of... )
One certainly can fuel activity with carbohydrates, but a fat-adapted person should have no trouble with physical activity on a (very) low carbohydrate diet. Interestingly, a fat-adapted athlete can still use carbohydrates for supplemental fuel before, during, or immediately following extreme exertion (no adaptation is required for short-term use of carbohydrates).
[+] [-] randallsquared|8 years ago|reply
Why would they make such a claim? Anyone who has done keto and worked out has probably had the experience of doing quite a lot of physical activity while having had no carbohydrate intake at all for half a day before, or more.
[+] [-] roystonvassey|8 years ago|reply
As someone who has been on a low-carb diet for 3 years, on and off, I definitely don't notice any difference in performance, mood or productivity while on a low-carb diet. Too many people (esp. those in a desk job) over estimate their physical activity levels and think they need more carbs.
Sure, if you're an athlete, all this doesn't apply to you. But, for the vast majority (who in the present day) lead highly sedentary lifestyles, it's about time we encourage them to get off carbs as much as possible.
[+] [-] smn1234|8 years ago|reply
[+] [-] internetman55|8 years ago|reply
[+] [-] unknown|8 years ago|reply
[deleted]
[+] [-] rhinoceraptor|8 years ago|reply
[+] [-] cageface|8 years ago|reply
https://www.hsph.harvard.edu/nutritionsource/2017/09/08/pure...
Be careful making any changes to your diet based on these "findings". The healthiest populations on the planet eat plenty of carbs, but not refined sugars.
[+] [-] oaijdsfoaijsf|8 years ago|reply
What's really surprising is how many people on here are like, "of course, ketogenic diets!" Where is all the skepticism that is so vividly on display when discussing the latest Google or Facebook product announcement?
[+] [-] CuriouslyC|8 years ago|reply
[+] [-] unknown|8 years ago|reply
[deleted]
[+] [-] blubb-fish|8 years ago|reply
[+] [-] shlant|8 years ago|reply
1. The study "did not analyze which specific source of carbohydrates (e.g., sugar/refined carbs versus whole-grain products) may contribute to the detrimental effects of carbs observed, especially since income and wealth do impact the quality of dietary choices significantly."
This is HUGE. Any study or person that attempts to label an entire macronutrient as "bad" or "evil" is not helping anyone understand the whole picture. The most nutritious foods in the world are carbs. Many of the least nutritious foods are also carbs. Not distinguishing the two gets us nowhere.
2. With this study and most high fat/keto diet studies as well, the timeline is not long enough to tell us about true "lifespan" impact. This one is over 7.4 years. I know it's more difficult to do 10, 20, 30 year studies, but until something can be correlated over those timespans, I would not bet everything on that diet for longevity. There are a handful of generational studies, and almost all have shown that "high carb" or more specifically "plant based" ARE good for longevity. Not saying high fat aren't good for longevity as well, but we have yet to really see examples yet.
3. As many who have tried Keto specifically will tell you (as some have mentioned in the comments), it is very difficult to maintain a ketogenic state. You have to be very disciplined, and this is made harder when you are a social person. This is a big problem when talking about diet and longevity. If it's not fairly easy to maintain, then it's not a feasible diet for longevity where the average person is concerned.
4. As someone else mentioned, the percentage of carbs that the studies participants were eating were not even close to the level required for a Keto Diet
[+] [-] cup-of-tea|8 years ago|reply
Instead I have taken a simpler approach: I observe the lifestyles of people who are healthy and live a long time. I have observed that eating simply "good, old-fashioned" home cooked food is important. My grandmother lived into her 90s. Ate fat and carbs. Julia Child lived into her 90s. Ate fat and carbs. Edna Lewis lived into her 90s. Ate fat and carbs. I could go on. Just do what they did and you'll have as good a chance as any.
[+] [-] maxxxxx|8 years ago|reply
Same for exercise. We already know how to exercise but there are always people who want to make money by repackaging it.
[+] [-] iridium|8 years ago|reply
[+] [-] guelo|8 years ago|reply
[+] [-] roystonvassey|8 years ago|reply
Especially, with something related to diet and nutrition, there is an ever evolving need to alter our habits with the way our lifestyles changed. The kind of life your grandmother led is vastly different than the way you do now.
Similarly, carbs were great when as a culture we embraced agriculture, started working the fields and were able to secure food supplies for emergencies and the next generation. Now, farm productivities have shot up, fewer of us are working directly on growing food and there's abundance of food choices all around. We no longer need the easy glucose that we needed earlier. So, it is important that we change our dietary choices if we want to lead healthier lives.
[+] [-] whalesalad|8 years ago|reply
The trouble comes with the way society has been conditioned to have carbs with every meal. Like 90% of the food my peer group eats are surrounded in carbs. Even for a company-wide lunch in the office: the go-to is usually a couple dozen pizzas.
Once you’ve lived low carb for a long time you look at people in line at a coffee house grabbing a bagel and a milkshake and just feel bad for the crash they will have later.
I’m happy to see Keto becoming more and more socially known. Accessiblity around low carb options is getting better and better. My favorite will always be a protein style burger from In-N-Out though.
[+] [-] hduwvzvshsuz|8 years ago|reply
[+] [-] cup-of-tea|8 years ago|reply
[+] [-] coldcode|8 years ago|reply
[+] [-] keymone|8 years ago|reply
[+] [-] gebeeson|8 years ago|reply
[+] [-] mentallimits|8 years ago|reply
[+] [-] miguelrochefort|8 years ago|reply
The worst part is not being able to eat/drink at social events, and dehydration.
The best part is never feeling hungry, stable energy levels throughout the day, and not needing to sleep as much.
I also tend to binge a lot when off keto...
[+] [-] jrs95|8 years ago|reply
[+] [-] wasted_intel|8 years ago|reply
[+] [-] huehehue|8 years ago|reply
Mainly asking because my diet yesterday was a six pack of Kirin Ichiban beer, a double cheeseburger, and a large P. Terry's chocolate shake, and I felt fine and still had a very productive day. I want to know why I'm able to tolerate stuff like that, and how/if that armor might start falling off as I get older.
[+] [-] 189243234|8 years ago|reply
I am pretty sure that isn't conditioning. Eating a burger with no chips is just plain wrong, and the same the other way around as well. When I am eating rice and meat together, if I eat just meat, it doesn't taste good. It is so specific, that there is a specific amount of rice that has to go with the meat. Everyone knows this. That can't possibly be conditioning. People complain of "too little rice", "too much meat" etc. No one could have been conditioned so specifically.
[+] [-] cko|8 years ago|reply
This section of the article does not correspond to the title. In fact it seemed all over the place, then goes on to conclude ‘maybe it’s refined sugars.’
[+] [-] bigtunacan|8 years ago|reply
[+] [-] lurcio|8 years ago|reply
https://news.ycombinator.com/item?id=8138784
https://news.ycombinator.com/item?id=9956839
[+] [-] kbougy|8 years ago|reply
[+] [-] shlant|8 years ago|reply
[+] [-] trevyn|8 years ago|reply
[+] [-] smn1234|8 years ago|reply
[+] [-] unknown|8 years ago|reply
[deleted]
[+] [-] bmcusick|8 years ago|reply
I hate associational studies like this which don't distinguish between types of carbohydrates (sugar vs starch) or other factors, like whether they were eating whole meals of natural foods or snacking on potato chips 24/7.
But at least they've finally noticed they were completely wrong about saturated fat for 80 years.
[+] [-] H1Supreme|8 years ago|reply
Stick to fibrous veggies, beans, nuts, some fruit (berries are best), and you'll be just fine eating carbs.
I'm not contesting the fact that ketogenic diets work for people. But this study is kinda bullshit since it's basically alluding to the worst kind of high GI refined carbs
[+] [-] shepardrtc|8 years ago|reply
So does this mean the glucosamine chondroitin pills I take for my joints will help reduce glucose conversion and extend my lifespan?
[+] [-] heliodor|8 years ago|reply
The summary text says there's causality. A few paragraphs into the study, the text interchangeably uses causality and correlation:
>> found that carbohydrate intake was associated with increased total mortality.
>> By contrast, any type of dietary fat reduced the likelihood of dying.
[+] [-] sjroot|8 years ago|reply
[+] [-] shlant|8 years ago|reply
See my comment: https://news.ycombinator.com/item?id=15465516
[+] [-] kaolti|8 years ago|reply
[+] [-] marze|8 years ago|reply
Eliminate sugar, increase saturated fat. This study provides little guidance on question “is total keto good or not”.
[+] [-] drpgq|8 years ago|reply
That's interesting.
[+] [-] metalliqaz|8 years ago|reply
[+] [-] digitalsushi|8 years ago|reply