23 replies to this topic

[Skötkonung]

Scientists have produced new evidence suggesting eating lots of red and processed meat damages health. They found big meat eaters had a raised risk of death from all causes over a ten-year period. In contrast, a higher intake of white meat was associated with a slightly reduced risk of death over the same period. The US study, featured in Archives of Internal Medicine, was based on more than 500,000 people.

Death link to too much red meat
http://news.bbc.co.u...lth/7959128.stm

[Forever21]

http://www.cnn.com/2...span/index.html

Edited by Forever21, 24 March 2009 - 03:10 AM.

[Ben]

Beat me to posting the article!


The article mentions that red meat and processed meat can lead to cancers and early death. By this do they mean that red meat in conjunction with processed meat or red meat and or processed meat can lead to cancers. Who knows? The article doesn't spell out so it'd be great if someone could pull the original article up.

Because I mean, if they fed the experimental group red meat and processed meat then it's not really a surprise to me that they suffered a greater amount of cancers and had an earlier death rate.

[Johan]

I don't eat very much meat myself, but correlation doesn't necessarily imply causation. I don't have access to the full-text study, but the lower meat intake and the associated lower mortality rate could both be due to a third, common thing, like reduced calorie intake in the low-meat eaters, for example. Only the full-text paper will tell us.

That said, there have been a few previous studies finding roughly the same thing. I can't seem to find them at the moment, though.

[Matt]

Hardly ever had any red meat in my whole life, just tastes horrible =/ The general findings for red meat seem to be that it isn't good for health and longevity. Best to stick to chicken and fish if you like meat and occasionally eat red meat if you wish. I've been vegetarian for over a year now anyway.

[Forever21]

Better yet, support MF aggressively.

[VictorBjoerk]

is this the red meat itself or just all chemicals meatproducts contain. One may wonder that.

[frederickson]

same weakness applies here as to all studies of this nature...

this study does not tell us much since they did not adjust for other poor dietary habits associated with those who generally eat a lot of red meat - especially high sugar/refined carbs and poor quality fat intake.

[RoadToAwe]

Here is the actual study:

http://archinte.ama-.../full/169/6/562

Attached Files

•  Meat_Intake_Mortality.pdf   109.53KB   43 downloads

[Skötkonung]

Here is the actual study:

http://archinte.ama-.../full/169/6/562

Thanks! I forwarded the study to Mark Sisson (of Marksdailyapple.com) and Dr. Eades (of Proteinpower.com) to see if either of them are willing to weigh in the on the data.

[Forever21]

Holy cow.

http://pagingdrgupta...ating-red-meat/

[Skötkonung]

I received an email back from Mark Sisson:

I read the study, and I'm currently preparing a post on it. Should be up within a week!

So for those of you who follow his blog, keep an eye out!

[JLL]

Hardly ever had any red meat in my whole life, just tastes horrible =/ The general findings for red meat seem to be that it isn't good for health and longevity. Best to stick to chicken and fish if you like meat and occasionally eat red meat if you wish. I've been vegetarian for over a year now anyway.

What are these findings? Can you post references? Not processed meat but red meat.

[drmz]

How did they handle the variable "preparation" ? Americans BBQ alot, not really the ideal way to prepare your t-bone steak.
I don't eat meat myself (only on rare occasions when i cannot resist the shoarma craving), but being vegetarian doesn't seem to lower colorectal cancer incidences.(which one would expect to be higher for meat eaters)



Cancer incidence in vegetarians: results from the European Prospective Investigation into Cancer and Nutrition (EPIC-Oxford)1,2,3,4
Timothy J Key, Paul N Appleby, Elizabeth A Spencer, Ruth C Travis, Andrew W Roddam and Naomi E Allen
1 From the Cancer Epidemiology Unit, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom.

2 Presented at the symposium, "Fifth International Congress on Vegetarian Nutrition," held in Loma Linda, CA, March 4–6, 2008.

3 Supported by Cancer Research UK, Medical Research Council.

4 Reprints not available. Address correspondence to TJ Key, Cancer Epidemiology Unit, University of Oxford, Richard Doll Building, Roosevelt Drive, Oxford OX3 7LF, United Kingdom. E-mail: tim.key@ceu.ox.ac.uk.


ABSTRACT

Background: Few prospective studies have examined cancer incidence among vegetarians.

Objective: We report cancer incidence among vegetarians and nonvegetarians in the European Prospective Investigation into Cancer and Nutrition–Oxford (EPIC-Oxford) study.

Design: This was a prospective study of 63,550 men and women recruited throughout the United Kingdom in the 1990s. Cancer incidence was followed through nationwide cancer registries.

Results: The standardized incidence ratio for all malignant neoplasms for all participants was 72% (95% CI: 69%, 75%). The standardized incidence ratios for colorectal cancer were 84% (95% CI: 73%, 95%) among nonvegetarians and 102% (95% CI: 80%, 129%) among vegetarians. Comparing vegetarians with meat eaters and adjusting for age, sex, and smoking, the incidence rate ratio for all malignant neoplasms was 0.89 (95% CI: 0.80, 1.00). The incidence rate ratio for colorectal cancer in vegetarians compared with meat eaters was 1.39 (95% CI: 1.01, 1.91).

Conclusions: The overall cancer incidence rates of both the vegetarians and the nonvegetarians in this study are low compared with national rates. Within the study, the incidence of all cancers combined was lower among vegetarians than among meat eaters, but the incidence of colorectal cancer was higher in vegetarians than in meat eaters.

[JLL]

Here's my blog post on the subject:

Red meat and mortality: a closer look at the evidence

[wydell]

I am sure he will find problems with the study if he believes in eating high amounts of red meat, as would anyone who believes in eating high amounts of red meat.

People generally cite studies to support their own beliefs and find flaws in studies that do not support their beliefs.

Most of the studies performed, whether high in red meat, or high in carb, are not based upon the mostly healthy versions of those diets, so it's hard to come to any conclusions.

I received an email back from Mark Sisson:

I read the study, and I'm currently preparing a post on it. Should be up within a week!

So for those of you who follow his blog, keep an eye out!

[Skötkonung]

I am sure he will find problems with the study if he believes in eating high amounts of red meat, as would anyone who believes in eating high amounts of red meat.

People generally cite studies to support their own beliefs and find flaws in studies that do not support their beliefs.

Most of the studies performed, whether high in red meat, or high in carb, are not based upon the mostly healthy versions of those diets, so it's hard to come to any conclusions.

You're right, I think both of them will find fault with the study. I only sought their opinion so that both sides of the argument / debate could be represented.

Dr. Eades has already posted a blog entry on the study:
http://www.proteinpo...-and-mortality/

BTW, I agree completely with your statement on the aforementioned studies. I think designing a longitudinal study adhering to strict (read: healthy) versions of these diets would be very hard to conduct as most people don't seem to have the resolve to voluntarily stick to any particular eating pattern for a long period of time. If it were that easy, most of us would be doing CR.

[Ben]

Here is the actual study:

http://archinte.ama-.../full/169/6/562

Thank you very much :D

[Ben]

Ok, I'm going over the study now as this really concerns me (I'm a red meat addict). So far this leaps out at me:

1. "Red meat intake was calculated using the frequency of consumption and portion size information of all types of beef and pork and included bacon, beef, cold cuts, ham, hamburger, hotdogs, liver, pork, sausage, steak, and meats in foods such as pizza, chili, lasagna, and stew"


2. "Individuals aged 50 to 71 years were recruited from 6 US states"

- These are some old folks!

3. "Subjects who consumed more red meat tended to be married, more likely of non-Hispanic white ethnicity, more likely a current smoker, have a higher body mass index, and have a higher daily intake of energy, total fat, and saturated fat, and they tended to have lower education and physical activity levels and lower fruit, vegetable, fiber"

4. "There is a possibility that some residual confounding by smoking may remain;"

[nameless]

This may be a dumb question, as I only skimmed the study, but could the mortality data be skewed by vegetable intake? By this I mean, those who tend to eat lots of burgers, hotdogs, steaks, sausages, bacon, etc. probably aren't the biggest vegetable people in the World. They may have a side of fries and consider that their daily vegetable.

So could it be the lack of vegetables caused the increased mortality rates, not the meat itself?

And I'm not saying this as a defender of red meat, as I rarely eat it (buffalo burger once in a rare while).

[JLL]

This may be a dumb question, as I only skimmed the study, but could the mortality data be skewed by vegetable intake? By this I mean, those who tend to eat lots of burgers, hotdogs, steaks, sausages, bacon, etc. probably aren't the biggest vegetable people in the World. They may have a side of fries and consider that their daily vegetable.

So could it be the lack of vegetables caused the increased mortality rates, not the meat itself?

And I'm not saying this as a defender of red meat, as I rarely eat it (buffalo burger once in a rare while).

In a way, yes. They measured "vegetable intake", but it's not clear what that means exactly. And considering how bacon apparently counts as 'red meat', I wouldn't be surprised if the vegetable category was as vague. I also suggested on my blog that perhaps the heavy meat eaters ate a lot of processed carbs like bread and pizza and less healthy things like salads. If the rest of the health data (meat eaters exercised less, were less educated, ate more, weighed more, smoked more) is anything to go by, this seems quite plausible.

I'm not as big on red meat as some health bloggers out there, but I don't think this study really tells us much. I also think that much of the health issues of red meat have to do with cooking. I'd like to see some studies on raw meat (including perhaps rare steaks and such) and health

[kismet]

I'll read Eades' blog later. Some thoughts (mostly addressing JLL's blog post):

I'm not as big on red meat as some health bloggers out there, but I don't think this study really tells us much. I also think that much of the health issues of red meat have to do with cooking. I'd like to see some studies on raw meat (including perhaps rare steaks and such) and health

Just because it supports a generally held belief and the conclusions of some (but not all) other epidemiologic trials doesn't mean "it tells us nothing". Other grave short-comings may be more of a problem, though.

it kind of draws the carpet from under the idea that all meat is inherently bad, and generally makes for a lousy meat-bashing party.
I thought your blog is more neutral than that.  I think you are wrong with you assumption, as far as I know red meat has always had a worse reputation than other meats. At least we have a good mechanistical hypothesis to explain its effects on CVD mortality (?) and/or colorectal cancer compared to other meats (the heme iron hypothesis, or is it outdated?).
On the other hand I can understand that you are angry at pointless meat-bashing.

What argues in favour of a real relationship? Red meat shows the expected does-response relationship and it's still strong when adjusted for confounding variables. White meat on other hand hardly showed a dose-response relationship.

The red meat category used in the questionnaire included the following items: "All types of beef and pork, including bacon, beef, cold cuts, ham, hamburger, hotdogs, liver, pork, sausage, steak, and meats in foods such as pizza, chili, lasagna, and stew."
I concur that definition is ridiculous and makes it difficult to draw a meaningful conclusion.

My guess is that maybe it's not red meat in general that is the problem here, but processed red meat – foods like hotdogs, bacon, etc.
The mortality was lower in the processed group than in the red meat group (which included processed and unprocessed meats), doesn't this argue against your hypothesis? On the other hand maybe you're right and the "red meat" category meats are exposed to more heat during preparation than the "processed meats".
In my opinion residual confounding (smoking, not adjusted for carb intake, other variables) is still a better explanation. Adjusting weakened the relationship, what would have happened if they further adjusted their model? I don't think it would have changed the conclusion (i.e. a small increase in all-cause mortality), even if we compare the base model with the heavily adjusted model they use the difference is not that big. So adjusting for carb intake or another variable would hardly change the big picture, because those variables are not even as strong predictors of mortality as the variables they used to adjust in the first place (e.g. smoking, vegetable intake).
Although, it looks as if they did not adjust for fish intake which might be a pretty important variable.

In a way, yes. They measured "vegetable intake", but it's not clear what that means exactly.
Defining vegetable is easier than defining "red meat". Looking at the food questionaire I don't think that's an issue (they asked about overall vegetable intake and intake of specific vegetables e.g. broccoli).

It's also worth noting that the increase in mortality among meat eaters wasn't all that big. The relative total mortality risk from red meat consumption in the highest quintile compared to the lowest quintile was 1.31 in men and 1.36 in women, which means that men and women who ate the most red meat were 1.31 and 1.36 as likely to die from any cause than those who ate the least during the study.
I know that strictly speaking you are right (from a mathematical POV), but not from an epidemiologic view (if the relationship is causal). Even a single digit increase in all-cause mortality (of the majority of people) would mean millions of unnecessary deaths in the coming years.
" For overall mortality, 11% of deaths in men and 16% of deaths in women could be prevented if people decreased their red meat consumption to the level of intake in the first quintile." This is huge (if the relationship is causal).
The hailed vitamin D provides mortality benefits in the range of single digits (8% in a meta-analysis of interventional trials) to double digits (sometimes more; but averaged it's definitely not that much). If huge interventional trials will prove even an 8% decrease in mortality, vitamin D will be the biggest break-through of the last decades (at least when it comes to prevention and supplements)!

How did they handle the variable "preparation" ? Americans BBQ alot, not really the ideal way to prepare your t-bone steak.
I don't eat meat myself (only on rare occasions when i cannot resist the shoarma craving), but being vegetarian doesn't seem to lower colorectal cancer incidences.(which one would expect to be higher for meat eaters)

I guess lower calcium and vitamin D intake is confounding (together they show a very strong association with colorectal cancer). Additionally vegetarian diets lack other benefical nutrients (e.g. creatine, carnitine), but I'm not sure if they influence cancer incidence. Vegetarians have been advised to supplements those substances for years.

Overall epidemiologic studies enable us to hazard a guess, nothing more. Still an educated guess is better than an uneducated guess. 

Does someone have a good grasp of the epidemiology of read meat & health outcomes overall? 

Edited by kismet, 28 March 2009 - 12:43 PM.

[JLL]

I'm not as big on red meat as some health bloggers out there, but I don't think this study really tells us much. I also think that much of the health issues of red meat have to do with cooking. I'd like to see some studies on raw meat (including perhaps rare steaks and such) and health

Just because it supports a generally held belief and the conclusions of some (but not all) other epidemiologic trials doesn't mean "it tells us nothing". Other grave short-comings may be more of a problem, though.

I didn't say it tells us nothing, I said it doesn't tell us much. I'm not suggesting that the reason it doesn't tell us much is because it suppots a generally held belief, I'm suggesting the reason is that the study was designed badly.

it kind of draws the carpet from under the idea that all meat is inherently bad, and generally makes for a lousy meat-bashing party.
I thought your blog is more neutral than that. I think you are wrong with you assumption, as far as I know red meat has always had a worse reputation than other meats. At least we have a good mechanistical hypothesis to explain its effects on CVD mortality (?) and/or colorectal cancer compared to other meats (the heme iron hypothesis, or is it outdated?).

Well, sometimes I'm neutral and sometimes I'm not I've drifted towards a more neutral style and was thinking maybe that was worded too strongly. It was meant as a joke, though.

The heme iron hypothesis sounds like it could be valid, but are there any studies showing that it's true?

What argues in favour of a real relationship? Red meat shows the expected does-response relationship and it's still strong when adjusted for confounding variables. White meat on other hand hardly showed a dose-response relationship.

Yes, but as the authors themselves point out, smoking (even after adjusting) might have been a confounding variable; and my suspicion is that there were more confounding variables they just didn't know or care to adjust for, one of them being carbohydrate intake.

The mortality was lower in the processed group than in the red meat group (which included processed and unprocessed meats), doesn't this argue against your hypothesis?

I was puzzled by this at first too, but if you look at the processed meat data, the intake of processed meats was much lower than that of red meat, so lower mortality seems logical.

I would find it odd that eating unprocessed red meat would somehow be worse than eating processed red meat.

On the other hand maybe you're right and the "red meat" category meats are exposed to more heat during preparation than the "processed meats".
In my opinion residual confounding (smoking, not adjusted for carb intake, other variables) is still a better explanation. Adjusting weakened the relationship, what would have happened if they further adjusted their model? I don't think it would have changed the conclusion (i.e. a small increase in all-cause mortality), even if we compare the base model with the heavily adjusted model they use the difference is not that big. So adjusting for carb intake or another variable would hardly change the big picture, because those variables are not even as strong predictors of mortality as the variables they used to adjust in the first place (e.g. smoking, vegetable intake).
Although, it looks as if they did not adjust for fish intake which might be a pretty important variable.

That may be true, but we don't know for sure based on this study. Most of the other epidemiological studies suffer from similar problems, because paleo diets and other meat-based diets that people are on for health reasons are still pretty uncommon; so many times the participants eating very little meat are the ones who lead healthy lives and the ones eating lots of meat are the ones eating burgers and fries all day. Adjusting for such variables might give us some insight, but it's not as good as a double-blind study, because metabolism is not always so simple.

Defining vegetable is easier than defining "red meat". Looking at the food questionaire I don't think that's an issue (they asked about overall vegetable intake and intake of specific vegetables e.g. broccoli).

I see. I didn't notice the actual food questionnaire when I read the paper, I'll have to take a look at it later on.

I know that strictly speaking you are right (from a mathematical POV), but not from an epidemiologic view (if the relationship is causal). Even a single digit increase in all-cause mortality (of the majority of people) would mean millions of unnecessary deaths in the coming years.
" For overall mortality, 11% of deaths in men and 16% of deaths in women could be prevented if people decreased their red meat consumption to the level of intake in the first quintile." This is huge (if the relationship is causal).

I guess you're right. I looked for relative cancer and mortality risks in other epidemiologic studies, and usually the numbers were much higher, but then, that doesn't necessarily mean much. I think I'll remove that part from the post.

[yucca06]

How did they handle the variable "preparation" ? Americans BBQ alot, not really the ideal way to prepare your t-bone steak.
I don't eat meat myself (only on rare occasions when i cannot resist the shoarma craving), but being vegetarian doesn't seem to lower colorectal cancer incidences.(which one would expect to be higher for meat eaters)

...

Conclusions: The overall cancer incidence rates of both the vegetarians and the nonvegetarians in this study are low compared with national rates. Within the study, the incidence of all cancers combined was lower among vegetarians than among meat eaters, but the incidence of colorectal cancer was higher in vegetarians than in meat eaters.

Because it was a study with vegetaRians. No vegetaLians.

Huge difference : eggs and dairy products...And lots of vegetarians are eating more dairy products than most of red meat eaters, wich is the worst thing they can do for their health...

Read the Chinese Study (Colin Campbell).