Comments on OBESITY PANACEA: Low Carb Diets: Doing More Harm Than Good?

I can either follow a low-carb diet, or I can go b...

2009-12-19T06:02:40.302-05:00

I can either follow a low-carb diet, or I can go back on the two type-2 diabetes medications my very impressed doctor cancelled, and gain back the fifty pounds I lost (without exercising more than the occasional longish walk) over the past six months.

My brother, who was diagnosed with fasting blood sugars of almost 300 (almost twice what I was) and peripheral neuropathy in his feet, normalizes his blood sugar purely through exercising after a moderately-low-carb dinner. The wretch eats bread. His foot problems are gone. How much exercise did the mice get?

the article says "high fat, high protein, low...

2009-12-15T12:13:52.419-05:00

the article says "high fat, high protein, low carb".
Maybe the problem is the high fat. Is it not possible to have a high protein, low carb diet with low to moderate fat? Could this change the outcome?

@ GnomeX Thanks very much for the great links. I h...

2009-12-07T22:32:55.976-05:00

@ GnomeX Thanks very much for the great links. I hadn't realized the original study had drawn so much criticism. Seems interesting that NEJM would now publish an editorial so heavily based on the paper.

Hmmm....

@ Beth, Thanks for the links! This has certainly...

2009-12-07T22:04:56.453-05:00

@ Beth,

Thanks for the links! This has certainly generated some lively discussion, I hope people continue to weigh in with their thoughts on the article!

Travis

In a bit of serendipity, Jenny on Diabetes Update ...

2009-12-07T19:42:01.384-05:00

In a bit of serendipity, Jenny on Diabetes Update has posted her frustration with rodent research and chronic disease. And in the comments, Steve Parker shared this on the study mentioned in the NEJM editorial:

-----
The December 3 issue of New England Journal of Medicine has an article - "A Look at the Low-Carb Diet" - that sounded interesting and educational.

Turns out it's simply about research done in mice. Not just your average mouse either, but a strain deficient in apolipoprotein E, which are particularly susceptible to atherosclerosis when fed a high-fat
Western diet.

The whole point seems to have been to cast aspersions on high-fat low-carb diets eaten by humans. To scare us into thinking that WE'LL develop atherosclerosis.
-----

Here's the link to Jenny's post:

http://diabetesupdate.blogspot.com/2009/12/rodent-research-blocks-progress-in.html

@ Jan - Thanks, Jan - you've just guaranteed m...

2009-12-07T17:41:07.188-05:00

@ Jan - Thanks, Jan - you've just guaranteed me a spiteful extra serving of mashed potatoes with my holiday dinner from my VERY offended mom :)

(Obviously kidding)

Thanks for your comment!

Supplement of the study with more detail on diets ...

2009-12-07T17:35:46.187-05:00

Supplement of the study with more detail on diets (took me awhile to realize this was here, doh): http://www.pnas.org/content/106/36/15418/suppl/DCSupplemental

Eades attack: http://www.proteinpower.com/drmike/cardiovascular-disease/do-statinators-dream-of-engineered-mice/

Great post from hyperlipid: http://high-fat-nutrition.blogspot.com/2009/08/low-carbohydrate-high-protein-and-apoe_28.html

I found it typical. Not only do mice translate unp...

2009-12-07T16:52:14.737-05:00

I found it typical. Not only do mice translate unpredictable to men. They even translate unpredictable to other strain of mice.

Although the NEJM is a prestigious journal with a stellar impactfactor, but they do tend to be biased. I can recall the rejection of the Lyon Heart study that showed lifesaving properties of canola oil without lowering cholesterol. The editor wrote that could not be true.

The authors did publish the study (JAMA), but they had to change the title into 'Mediterrean diet'. I know the Americans aren't to strong in geography and somehow are bothered that canada is a neighbor, but this one gets beyond wildly creative.

Really don't want to offend your mom, but hold your horses (for a while)

@ Kate Porter - Excellent comments Kate! Regardi...

2009-12-07T16:08:53.445-05:00

@ Kate Porter - Excellent comments Kate!

Regarding the use of mice - of course we need to see human studies to see if the same pans out in free-living humans. Part of the advantage of using mice is really the other side of the cirticism you pose - if you want to test effects of certain diets on an outcome - mice are much better subjects than humans to study such a question. Mice could only eat the diet they were given - humans can vary their diet tremendously from day to day, thus don't make ideal subjects for such studies. Again, it is true that we need human studies but basic science has its strength in removing some of the countless confounders inherent to human studies. My research is in humans, and when it comes time to analyse my data - I am always a bit envious of basic scientists who have so much more control of the environment of their subjects (I can only co-vary for so many variables in my analysis:)

@ Yoni Thanks for the comment! I hope you got my email with a PDF of the article. As you probably know - dietary macronutrient composition and health is not my direct area of research, so when I read the editorial I was quite intrigued - especially given that NEJM thought it worthy enough to publish and the fact it was written by a prominent scientist in the area - Steven Smith of Pennigton Biomedical Center.

Is the editorial premature? Maybe. As I stated in the post, the whole crux of the argument rests on the results of this one animal study.

The interesting thing Smith alludes to is the fact that common CVD risk factors may not be the right targets by which to judge the safety of a given diet, etc. The notion that the CVD risk status between the two groups of mice was identical and yet the plaque formation significantly greater in the low-carb group suggests other factors are at play other than the usual suspects. Thus, it is possible that the same studies that showed an improvement in the classical CVD risk factors in response to low-carb diet - those subjects may have had increased atherosclerotic plaque formation, but of course the variable was not measured.

All of this is simply speculation. I await a human study that assesses the effects of different diets on coronary calcium or some advanced marker of CVD risk other than the intermediate metabolic risk factors.

I don't have a subscription either, so am eage...

2009-12-07T15:35:54.239-05:00

I don't have a subscription either, so am eager for someone like one of the Drs. Eades or Stephan Guyenet or Kurt Harris gets a hold of this study and report.

I'm not a LC fanatic (I'm going for more of a moderate/paleo carbs approach myself), so tend to agree with Kate that food quality is also key. Our industrial diet is really a disaster whether you eat fat or carbs.

Hi Peter, Slightly odd to base one's atheroge...

2009-12-07T14:26:06.711-05:00

Hi Peter,

Slightly odd to base one's atherogenic conclusions on a mouse study as they don't always translate to people.

While I'm by no means a low-carber (my issue with it is its non-sustainability for the vast majority of those trying it), data, also from NEJM in humans suggest that in fact its metabolic profile is superior with higher HDL and improved insulin sensitivity.

Will have a more careful read of the study but I wonder if this isn't a premature editorial?

Regards,
Yoni

I don't have an NEJM subscription, so haven...

2009-12-07T11:40:12.103-05:00

I don't have an NEJM subscription, so haven't read the article. However, a few things pop out at me as potential red flags.

1. This is based on a study in mice, being fed (presumably) processed mouse food. People are not mice, and we do not eat processed pellet food. While I recognize that animal models have an important place in health research, it sounds incredibly premature to me to extrapolate from one mouse study to make a blanket statement about a very large human diet range. However, this isn't my main concern. My main concern is

2. There's carbs, and then there's carbs. The traditional "low-carb" diet--i.e., the one that the diet industry refers to--typically means low in starch (potatoes, flour, etc) and high in protein and vegetables. However, vegetables are almost entirely carbs; they're just not starch carbs. If you look at total carbohydrate, a diet high in fruits, vegetables, and whole grains is very high-carb, as is a diet of white bread, potatoes, and gummy bears. But clearly the fruit/veggie diet is a lot healthier than the white bread/gummy bear diet. Which of those two high-carb diets corresponds to the "high-carb" diet the mice were on? There's really no way to make that kind of comparison. Similarly, a diet of red meat, bacon, and eggs is high in protein, as is a diet with a lot of beans, tofu, and egg whites--but they're not equivalently healthy.

A diet low in processed carbs, but high in fruits & veggies, would not be low-carb but would probably be a lot healthier than a "low-carb" diet that is mostly meat and fat. In the sense that the "low-carb diet" craze--i.e., Atkins, etc--is probably doing more harm than good, sure, no argument from me there. But I don't think it's valid to extrapolate from that to say that we should all eat lots and lots of "western" carbs (i.e., white flour and sugar).