7 ms·

Low-carbohydrate diets and all-cause and cause-specific mortality

53 points by spekcular 5y ago

Causality1 5y ago
The fatal flaw in this study is that it examined people with low carb diets, not people who adopted low carb diets. At worst it's misleading and at best it fails to address what effect the adoption of a low-carb meat based diet has on an obese person accustomed to a high carb diet. If you bacon your way to losing 150 pounds you're probably going to have a higher mortality than the average person, but probably less than the average 300 pound person.
- estaseuropano 5y ago
  Is it though? I think that's the point of the study - not all keto are equal. High meat keto increases mortality, high vegetable keto decreases mortality. That the same is true for non-diet diets is already well established so this just shows that even in diets high meat is unhealthy.
  - Causality1 5y ago
    High meat is unhealthy compared to a normal/healthy diet. The elephant in the room is whether an unhealthy overweight high-carb person is healthier on a high meat diet. Is it healthier to be a 350 pound man eating McDonald's every day or a 200 pound man eating steak and eggs? Keto may not be a healthy lifestyle but is it a better alternative for the morbidly obese?
- kcplate 5y ago
  My problem with these studies is that the headlines don’t tell the whole story of possible improvement of a persons mortality. As a insulin dependent type 2 diabetic that used to top 450lbs, my mortality rate was significantly higher then as opposed to now as a 250lb guy fully managing his diabetes with only a keto diet and exercise. So if keto kills me at 75, that is a hell of a lot better than diabetes killing me at 55. It’s also a lot tastier than a vegetarian low carb diet hat might squeeze in an extra 2 years.
memco 5y ago
> Limitations Diet and lifestyle characteristics were assessed with some degree of error, however, sensitivity analyses indicated that results were not unlikely to be substantially affected by residual or confounding or an unmeasured confounder. In addition, participants were not a representative sample of the U.S. population. Am I missing something or is this saying the data they used is known to be flawed and not reliable?
- gwillen 5y ago
  Good catch, it sure reads like an editing error for "not likely", meaning the opposite of what it says.
  - deleted 5y ago
    [deleted]
  - dunco 5y ago
    Could it be equally likely that they are simply recognising how difficult it is to use data from dietary studies? There are so many confounding factors that are very difficult to account for. part of the reason there is so little consensus in the field.
- nipponese 5y ago
  Ultimately you're going to have to weigh a basket of info: methodology vs. limitations vs. results vs. number of citations vs. similar studies, etc, before you can come to your own conclusion. In this case, almost 80 other journal papers cited this paper as reputable.
fouc 5y ago
Interesting conclusion: > A low-carbohydrate diet based on animal sources was associated with higher all-cause mortality in both men and women, whereas a vegetable-based low-carbohydrate diet was associated with lower all-cause and cardiovascular disease mortality rates. I'm not familiar enough with reading scientific whitepapers to judge if it's good science or not though. As someone that isn't vegan, and thinks that low-carb diets are pretty good, I don't really want to believe this result. :)
- TedDoesntTalk 5y ago
  Note that vegans don’t necessarily eat low-carb diets. Not all vegetable sources are low-carb.
  - thiagocsf 5y ago
    Tell me about it! Outside of green leaves, it was tough to find low-carb vegetarian foods that don’t leave you hungry. Cauliflower is one of them.
- timeon 5y ago
  Regardless of the result... I like your honesty.
themgt 5y ago
There's a pretty good response to this study here: https://deniseminger.com/2010/09/08/brand-spankin-new-study-are-low-carb-meat-eaters-in-trouble/ https://deniseminger.com/2010/09/08/brand-spankin-new-study-... In short, based on questionable dataset, "low carb" wasn't really low carb (37-60% calories), "vegetable-based" diet was still ~30% animal source calories (vs 45% for "animal-based"), vegetable group generally ate more varied/whole food plants and had healthier behaviors, various other contradictory health outcomes within the deciles. Most people should probably be eating more plants, but this study really doesn't demonstrate "low-carbohydrate diet based on animal sources was associated with higher all-cause mortality, whereas a vegetable-based low-carbohydrate diet was associated with lower all-cause and cardiovascular disease mortality rates" especially as most people would understand the terms "low-carb" / "based on animal sources" / "vegetable-based".
superqd 5y ago
So I studied as a scientist (physicist) and have a high bar for what constitutes a meaningful scientific study and scientific result. A food frequency questionnaire, of the sort this study's results are based on, means very little scientifically. No meaningful result can be drawn, and I consider it borderline immoral, given the type of affect this could have on people's behaviors, to assert a conclusion based on such poorly conducted research. Asking people to quantify their eating habits over the previous several years and expect to have meaningful quantitative results is impossible. I can barely quantify my eating habits over the last few months. There are just far too many variables that cannot be controlled for in such research as to render any conclusion impossible. We need meaningful nutritional research, desperately, and this just isn't it. It angers me deeply that this passes as science that will get reported on, used as "proof" in justifying recommendations, etc.
- hattmall 5y ago
  Kind of questionable perhaps, but a good place to do these studies would be on prisoners. You could potentially do it by simply monitoring their intake and not actually changing anything in the offering. It should be fairly reasonable to get a reliable intake report.
  - superqd 5y ago
    Yeah, the ethics would be tough, but essentially to really do nutrition research, you MUST control the food intake. Control for age, weight, calories and activity, and vary only the dietary makeup to varying degrees, etc.
    - flukus 5y ago
      > Yeah, the ethics would be tough What sort of ethical issues are you thinking? I would have thought higher grade meals than you'd find in a standard prison would entice all the volunteers you could want. There's probably other groups were some good quality meals would be just as enticing, like college students. A bigger practical issue in prisons would be things like the high prevalence of hepatitis and drug use along with all the confounding factors (like poverty) that lead them to end up in prison.
deleted 5y ago
[deleted]
reureu 5y ago
This article is from 2010. However, the last author in this study was just prominently mentioned in an article published last week: https://www.sciencedirect.com/science/article/pii/S0033062021000670 https://www.sciencedirect.com/science/article/pii/S003306202...
a11r 5y ago
Gary Taubes has done a pretty comprehensive takedown of the Nurese Health study[http://garytaubes.com/science-pseudoscience-nutritional-epidemiology-and-meat/ http://garytaubes.com/science-pseudoscience-nutritional-epid...] and all the wrong conclusions the good folks at Department of Nutrition, Harvard School of Public Health have managed to torture out of it.
- fatsdomino001 5y ago
  I'm immediately skeptical of anyone who describe their criticism of a study as a "takedown"
IronWolve 5y ago
Low carb is recommended for diabetics and even some epilepsy cases. Then there is diets, people who do low carb and never really do full time ketogenic diet, or fluctuate between the two, which is my case. I'd like to see a study for healthy people on low carb and the benefits.
JMTQp8lwXL 5y ago
As someone who's experimented with varying degrees of carbohydrates in my diet: I've had issues with high-carb diets (bloating). I've had issues with low-carb diets (emergency runs to the bathroom, to put it mildly). My next attempt: a medium carb diet (or, more precisely, low medium, ~50-80g/day). My body seems to function well with some, but too much is no good either. Like most things, moderation.
- TedDoesntTalk 5y ago
  I would guess that the content of your low-carb diet was the cause of your bathroom problems, not the lack of carbs itself. Did you try other low-carb foods or just give up? There are many options and if it can figure out which ones are problematic for you, eliminate those and eat others.
- coffexx 5y ago
  I can speak from experience on some of those lovely symptoms. When I was doing my first 9 months of <20g of carbs and a 30-40% caloric deficit, I eventually dipped down low enough that I could cover it in a single meal. So I figured I'd give intermittent fasting a go. Almost immediately I noticed a difference. What was once solid was no more... Almost like the first week or so of the diet where my gut was getting used to the new order of things. After a bit of trial and error I figured out that it was the large amount of fat in a single sitting that was causing my distress. I'm guessing here, but perhaps it isn't possible to absorb it all before it makes it out the other end? In any case, I went back to 2 meals a day and all was well again.
- Semaphor 5y ago
  > low medium, ~50-80g/day Just to put it in context: That’s far less than the low-carb this study is talking about ;)
- gremlinsinc 5y ago
  Might want to look at which carbs... Greasy carbs give the runs more, esp. if you have a gallbladder issue. Also protein drinks...but I think that's because of milk, and I'm lactose intolerant.
anonygler 5y ago
It’s worth noting that a vegan low carb diet is expensive and time consuming. Is it associated with a lower mortality rate, or is it your financial position that gives you a better quality of life? An animal based keto diet is way easier to sustain thanks to fast food adoption.
- vixen99 5y ago
  Read the paper. There is no mention of a purely plant based vegan diet in the study. Moreover the authors already note the point you're making. "In addition, the participants of our cohorts have higher educational status and better availability of health care coverage. Therefore, results may not be directly generalizable to the general population."

53 points by spekcular 5y ago

The fatal flaw in this study is that it examined people with low carb diets, not people who adopted low carb diets. At worst it's misleading and at best it fails to address what effect the adoption of a low-carb meat based diet has on an obese person accustomed to a high carb diet. If you bacon your way to losing 150 pounds you're probably going to have a higher mortality than the average person, but probably less than the average 300 pound person.

estaseuropano 5y ago
Is it though? I think that's the point of the study - not all keto are equal. High meat keto increases mortality, high vegetable keto decreases mortality. That the same is true for non-diet diets is already well established so this just shows that even in diets high meat is unhealthy.
- Causality1 5y ago
  High meat is unhealthy compared to a normal/healthy diet. The elephant in the room is whether an unhealthy overweight high-carb person is healthier on a high meat diet. Is it healthier to be a 350 pound man eating McDonald's every day or a 200 pound man eating steak and eggs? Keto may not be a healthy lifestyle but is it a better alternative for the morbidly obese?
kcplate 5y ago
My problem with these studies is that the headlines don’t tell the whole story of possible improvement of a persons mortality. As a insulin dependent type 2 diabetic that used to top 450lbs, my mortality rate was significantly higher then as opposed to now as a 250lb guy fully managing his diabetes with only a keto diet and exercise. So if keto kills me at 75, that is a hell of a lot better than diabetes killing me at 55. It’s also a lot tastier than a vegetarian low carb diet hat might squeeze in an extra 2 years.

memco 5y ago

> Limitations Diet and lifestyle characteristics were assessed with some degree of error, however, sensitivity analyses indicated that results were not unlikely to be substantially affected by residual or confounding or an unmeasured confounder. In addition, participants were not a representative sample of the U.S. population. Am I missing something or is this saying the data they used is known to be flawed and not reliable?

gwillen 5y ago
Good catch, it sure reads like an editing error for "not likely", meaning the opposite of what it says.
- deleted 5y ago
  [deleted]
- dunco 5y ago
  Could it be equally likely that they are simply recognising how difficult it is to use data from dietary studies? There are so many confounding factors that are very difficult to account for. part of the reason there is so little consensus in the field.
nipponese 5y ago
Ultimately you're going to have to weigh a basket of info: methodology vs. limitations vs. results vs. number of citations vs. similar studies, etc, before you can come to your own conclusion. In this case, almost 80 other journal papers cited this paper as reputable.

fouc 5y ago

Interesting conclusion: > A low-carbohydrate diet based on animal sources was associated with higher all-cause mortality in both men and women, whereas a vegetable-based low-carbohydrate diet was associated with lower all-cause and cardiovascular disease mortality rates. I'm not familiar enough with reading scientific whitepapers to judge if it's good science or not though. As someone that isn't vegan, and thinks that low-carb diets are pretty good, I don't really want to believe this result. :)

TedDoesntTalk 5y ago
Note that vegans don’t necessarily eat low-carb diets. Not all vegetable sources are low-carb.
- thiagocsf 5y ago
  Tell me about it! Outside of green leaves, it was tough to find low-carb vegetarian foods that don’t leave you hungry. Cauliflower is one of them.
timeon 5y ago
Regardless of the result... I like your honesty.

themgt 5y ago

There's a pretty good response to this study here: https://deniseminger.com/2010/09/08/brand-spankin-new-study-are-low-carb-meat-eaters-in-trouble/ https://deniseminger.com/2010/09/08/brand-spankin-new-study-... In short, based on questionable dataset, "low carb" wasn't really low carb (37-60% calories), "vegetable-based" diet was still ~30% animal source calories (vs 45% for "animal-based"), vegetable group generally ate more varied/whole food plants and had healthier behaviors, various other contradictory health outcomes within the deciles. Most people should probably be eating more plants, but this study really doesn't demonstrate "low-carbohydrate diet based on animal sources was associated with higher all-cause mortality, whereas a vegetable-based low-carbohydrate diet was associated with lower all-cause and cardiovascular disease mortality rates" especially as most people would understand the terms "low-carb" / "based on animal sources" / "vegetable-based".

superqd 5y ago

So I studied as a scientist (physicist) and have a high bar for what constitutes a meaningful scientific study and scientific result. A food frequency questionnaire, of the sort this study's results are based on, means very little scientifically. No meaningful result can be drawn, and I consider it borderline immoral, given the type of affect this could have on people's behaviors, to assert a conclusion based on such poorly conducted research. Asking people to quantify their eating habits over the previous several years and expect to have meaningful quantitative results is impossible. I can barely quantify my eating habits over the last few months. There are just far too many variables that cannot be controlled for in such research as to render any conclusion impossible. We need meaningful nutritional research, desperately, and this just isn't it. It angers me deeply that this passes as science that will get reported on, used as "proof" in justifying recommendations, etc.

hattmall 5y ago
Kind of questionable perhaps, but a good place to do these studies would be on prisoners. You could potentially do it by simply monitoring their intake and not actually changing anything in the offering. It should be fairly reasonable to get a reliable intake report.
- superqd 5y ago
  Yeah, the ethics would be tough, but essentially to really do nutrition research, you MUST control the food intake. Control for age, weight, calories and activity, and vary only the dietary makeup to varying degrees, etc.
  - flukus 5y ago
    > Yeah, the ethics would be tough What sort of ethical issues are you thinking? I would have thought higher grade meals than you'd find in a standard prison would entice all the volunteers you could want. There's probably other groups were some good quality meals would be just as enticing, like college students. A bigger practical issue in prisons would be things like the high prevalence of hepatitis and drug use along with all the confounding factors (like poverty) that lead them to end up in prison.

deleted 5y ago

[deleted]

reureu 5y ago

This article is from 2010. However, the last author in this study was just prominently mentioned in an article published last week: https://www.sciencedirect.com/science/article/pii/S0033062021000670 https://www.sciencedirect.com/science/article/pii/S003306202...

a11r 5y ago

Gary Taubes has done a pretty comprehensive takedown of the Nurese Health study[http://garytaubes.com/science-pseudoscience-nutritional-epidemiology-and-meat/ http://garytaubes.com/science-pseudoscience-nutritional-epid...] and all the wrong conclusions the good folks at Department of Nutrition, Harvard School of Public Health have managed to torture out of it.

fatsdomino001 5y ago
I'm immediately skeptical of anyone who describe their criticism of a study as a "takedown"

IronWolve 5y ago

Low carb is recommended for diabetics and even some epilepsy cases. Then there is diets, people who do low carb and never really do full time ketogenic diet, or fluctuate between the two, which is my case. I'd like to see a study for healthy people on low carb and the benefits.

JMTQp8lwXL 5y ago

As someone who's experimented with varying degrees of carbohydrates in my diet: I've had issues with high-carb diets (bloating). I've had issues with low-carb diets (emergency runs to the bathroom, to put it mildly). My next attempt: a medium carb diet (or, more precisely, low medium, ~50-80g/day). My body seems to function well with some, but too much is no good either. Like most things, moderation.

TedDoesntTalk 5y ago
I would guess that the content of your low-carb diet was the cause of your bathroom problems, not the lack of carbs itself. Did you try other low-carb foods or just give up? There are many options and if it can figure out which ones are problematic for you, eliminate those and eat others.
coffexx 5y ago
I can speak from experience on some of those lovely symptoms. When I was doing my first 9 months of <20g of carbs and a 30-40% caloric deficit, I eventually dipped down low enough that I could cover it in a single meal. So I figured I'd give intermittent fasting a go. Almost immediately I noticed a difference. What was once solid was no more... Almost like the first week or so of the diet where my gut was getting used to the new order of things. After a bit of trial and error I figured out that it was the large amount of fat in a single sitting that was causing my distress. I'm guessing here, but perhaps it isn't possible to absorb it all before it makes it out the other end? In any case, I went back to 2 meals a day and all was well again.
Semaphor 5y ago
> low medium, ~50-80g/day Just to put it in context: That’s far less than the low-carb this study is talking about ;)
gremlinsinc 5y ago
Might want to look at which carbs... Greasy carbs give the runs more, esp. if you have a gallbladder issue. Also protein drinks...but I think that's because of milk, and I'm lactose intolerant.

anonygler 5y ago

It’s worth noting that a vegan low carb diet is expensive and time consuming. Is it associated with a lower mortality rate, or is it your financial position that gives you a better quality of life? An animal based keto diet is way easier to sustain thanks to fast food adoption.

vixen99 5y ago
Read the paper. There is no mention of a purely plant based vegan diet in the study. Moreover the authors already note the point you're making. "In addition, the participants of our cohorts have higher educational status and better availability of health care coverage. Therefore, results may not be directly generalizable to the general population."