Marks Daily Apple
Serving up health and fitness insights (daily, of course) with a side of irreverence.
14 Mar

Will Eating Red Meat Kill You?

This is another special guest post from our favorite study-dismantler, Denise Minger. Read all of her previous Mark’s Daily Apple articles here, here, here and here, pay her website a visit, and stay tuned for her upcoming book “Death by Food Pyramid” due out later this year.

We’re already 74 days into the new year, which can only mean one thing: it’s high time for our latest episode of Science Says Meat Will Kill You, complete with a brand new study and commercial-free viral media coverage! Have a seat and tune in (or at least set your DVR for later viewing).

If you haven’t had at least one family member, coworker, or soon-to-be-unfriended Facebook acquaintance send you this study as a reminder that you’re killing yourself, you’re either really lucky or your inbox is broken. Thanks to an observational study called Red Meat Consumption and Mortality freshly pressed in the Archives of Internal Medicine, a slew of bold headlines exploded across every conceivable media outlet this week:

Media sensationalism aside, the study does seem to spell trouble for proud omnivores. Unlike some similar publications we’ve seen on meat and mortality, this one says that red meat doesn’t just make you die of heart disease and cancer; it makes you die of everything. Following over 120,000 women and men from the Nurses’ Health Study and the Health Professional’s Follow-up Study for 28 and 22 years respectively, researchers found that a single daily serving of unprocessed red meat was associated with a 13% increased risk of death from all causes, while a single serving of processed red meat—the equivalent of one hotdog—was associated with a 20% increased risk.

And in case that’s not enough to chew on, there’s more: the researchers waved their statistical wands and declared you could outrun death for a few more years by swapping red meat for so-called “healthier foods” like nuts, chicken, or whole grains. In fact, the researchers suggest that up to one in ten of the deaths that struck their study participants could’ve been prevented if everyone had kept their red meat intake under half a serving per day!

But if you’ve been hanging around the nutrition world for very long, you’ve probably realized by now that health according to the media and health according to reality are two very different things—and even scientific studies can be misrepresented by the researchers who conduct them. Is our latest “killer meat” scare a convincing reason to ditch red meat? Is it time to put a trigger lock on your lethal grass-fed beef when the young’uns are around? Or is there more to this story than meats the eye? (Sorry, I had to.)

Observations vs. Experiments

Before we even dig into what this study found, let’s address an important caveat that the media—and even the researchers, unless they were terribly misquoted—seem to be confused about. What we’ve got here is a garden-variety observational study, not an actual experiment where people change something specific they’re doing and thus make it possible to determine cause and effect. Observations are only the first step of the scientific method—a good place to start, but never the place to end. These studies don’t exist to generate health advice, but to spark hypotheses that can be tested and replicated in a controlled setting so we can figure out what’s really going on. Trying to find “proof” in an observational study is like trying to make a penguin lactate. It just ain’t happening… ever.

Nonetheless, the media blurbs—and even quotes from the scientists themselves—suggest this study has a major case of mistaken identity. The lead researcher Frank Hu claimed the study “provides clear evidence that regular consumption of red meat, especially processed meat, contributes substantially to premature death,” despite the fact that the study is innately incapable of providing such evidence. It’s as if someone pulled a Campbell on us. Only an actual experiment, with controls and manipulated variables, could start confirming causation.

But the study’s over-extrapolation isn’t really that surprising. A conclusive experiment is what every observational study secretly yearns to be, deep down in its confounder-riddled, non-randomized heart. And like pushy stage mothers, some researchers want their observational studies to be more talented and remarkable than they truly are—leading to the scientific equivalent of a four year old wobbling around in stilettos at a beauty pageant. Our study at hand is a perfectly decent piece of observational literature, but as soon as its authors (or the media) smear it with lipstick and make it sing Patsy Cline songs on stage, it’s all downhill from there.

Food Frequency Questionnaires: A Test of Superhuman Memory and Saint-like Honesty

To kick this analysis off, let’s take a look at how the study was actually conducted. As the researchers explain, all of the diet data came from a series of food frequency questionnaires (FFQs) that the study participants filled out once every four years, starting in the 1980s and ending in 2006. (If you’re feeling brave, you can read the questionnaire yourself (PDF) and try imagining how terribly the average, non-diet-conscious person might botch their responses.) The lifestyle and medical data came from additional questionnaires administered every two years.

The full text of our study offers some additional details (emphasis mine):

In each FFQ, we asked the participants how often, on average, they consumed each food of a standard portion size. There were 9 possible responses, ranging from “never or less than once per month” to “6 or more times per day.” Questionnaire items about unprocessed red meat consumption included “beef, pork, or lamb as main dish” (pork was queried separately beginning in 1990), “hamburger,” and “beef, pork, or lamb as a sandwich or mixed dish.” … Processed red meat included “bacon” (2 slices, 13 g), “hot dogs” (one, 45 g), and “sausage, salami, bologna, and other processed red meats” (1 piece, 28 g).

Notice that one of the foods listed under “unprocessed red meat”—and likely a major contributor to that category—is hamburger, the stuff fast-food dreams are made of. Although this study tracked whole grain intake, it didn’t track refined grain intake, so we know right away we can’t totally account for the white-flour buns wrapped around those burgers (or many of the other barely-qualifying-as-food components of a McDonald’s meal). And unless these cohorts were chock full of folks who deliberately sought out decent organic meat, it’s also worth noting that the unprocessed ground beef they were eating probably contained that delightful ammonia-treated pink slime that’s had conventional meat consumers in an uproar lately.

Next, we arrive at this little gem:

The reproducibility and validity of these FFQs have been described in detail elsewhere.

Ding ding, Important Thing alert! As anyone who’s spent much time on earth should know, expecting people to be honest about what they eat is like expecting one of those “Lose 10 pounds of belly fat” banners to take you somewhere other than popup-ad purgatory: the idealism is sweet and all, but reality has other plans.

And so it is with food frequency questionnaires. Ever since these questionnaires were first birthed unto the world, scientists have lamented their most glaring flaw: people tend to report what they think they should be eating instead of what actually goes into their mouth. And that’s on top of the fact that most folks can barely remember what they ate yesterday, much less what they’ve eaten over the past month or even the past year.

As a result, researchers compare the results of food frequency questionnaires with more accurate “diet records”—where folks meticulously weigh and record everything they eat for a straight week or two—to see how the data matches up. If we follow that last quote to the links it references, we end up at one of the validation reports for the food frequency questionnaire used with the Health Professionals Follow-up Study. Here’s where it gets interesting:

Foods underestimated by the FFQs compared with the diet records (ie, the gold standard) included processed meats, eggs, butter, high-fat dairy products, mayonnaise and creamy salad dressings, refined grains, and sweets and desserts, whereas most of the vegetable and fruit groups, nuts, high-energy and low-energy drinks, and condiments were overestimated by the FFQs.

This shouldn’t come as a shocker if we consider human psychology. Unless we literally live in a cave, most of us are constantly inundated with messages about how high-fat dairy, meat, sweets, desserts, and anything delicious and creamy is going to either make us fat or give us a heart attack—while it’s more like hallowed be thy name for fruits and veggies. Is it any wonder that folks tend to under-report their intake of “bad” foods and over-report their intake of the good ones? Who wants to admit—in the terrifying permanency of a food questionnaire—that yes, they do bury their salad in half a cup of Hidden Valley Ranch, and they do choose white bread because 12-Grain Oroweat tastes like lightly sweetened wood chippings, and sometimes they even go a full three days where their only vegetable is ketchup? If food frequency questionnaires were hooked up to a polygraph, we might see some much different data (and some mysteriously disappearing respondents).

Another reference in our study du jour takes us to a validation report for the Nurses’ Health Study questionnaire. And here we find the same trend:

Mean daily amounts of each food calculated by the questionnaire and by the dietary record were also compared; the observed differences suggested that responses to the questionnaire tended to over-represent socially desirable foods.

Of course, if everyone over-reported or under-reported their food intake with the same magnitude of inaccuracy, we could still find some reliable associations between food questionnaires and health outcomes. But it turns out that how much someone fudges their food reporting—especially for specific menu items—varies wildly based on their personal characteristics. Using an Aussie-modified version of the Nurses’ Health Study questionnaire, a study from Australia measured how accurately people reported their food intake based on their gender, age, medical status, BMI, occupation, school-leaving age, and use of dietary supplements. Like with the other validation studies, it compared the results of the food frequency survey with the Almighty Weighed Food Record.

The surprising results? Folks with a “diagnosed medical condition”—including high cholesterol, high triglycerides, diabetes, high blood pressure, stroke, cancer, and heart disease—were much more likely to mis-report their meat consumption than folks without a diagnosed medical condition, generally overestimating their true intake on food frequency questionnaires compared to the weighed food record. Why this occurred is one of life’s great mysteries, but it might have something to do with the fact that people who develop diet- and lifestyle-related diseases pay less conscious attention to what they eat. (In this study, women were also more likely to inaccurately report their intake for a wide variety of foods—a phenomenon that’s been examined in greater depth by other researchers.)

So what does this mean for studies based on food frequency questionnaires, like the one currently hijacking the news outlets? Unfortunately for lovers of scientific accuracy, it means that meat consumption and modern diseases might be statistically more likely to show up hand-in-hand by mere fluke. If sick folks have a tendency—for whatever reason—to say they’re eating more meat than they really are, that’ll have profound effects on any diet-disease associations that turn up in observational studies, where correlations hinge so heavily on the accuracy of the data. And if the results of that Australian study are applicable not only in the Land Down Under but also in the Land Up Over, it could mean that meat is pretty much doomed to look guilty by association with disease whenever food frequency questionnaires are involved. Woe is meat!

Red-Meatophiles: A Species of Their Own

Now that our confidence in food frequency questionnaires should be thoroughly and disturbingly shattered, let’s hop back to the study in question. To gauge the effects of red meat consumption on mortality, the researchers for our Red Meat Consumption and Mortality study divided folks up into five quintiles based on their red meat intake. The first quintile represents the people who reported the fewest servings per day, while the fifth quintile represents the shameless red-meat gluttons who indulged in the most (or rather, reported indulging in the most). Luckily for us, the researchers provided a magical table of marvels comparing various diet and lifestyle variables between the quintiles. Please take a minute to look at it yourself and, if you feel so compelled, bask in its glory.

If you secretly suspected that this was a “people who eat red meat do a lot of unhealthy things that make them die sooner” study, you can now gloat.

Here are a few lifestyle variables I graph-ified for greater visual impact. (“Red Meat Intake” is measured in servings per day, and “Physical Activity” is measured in hours of metabolic equivalent tasks.)

As you can see, the folks eating the most red meat were also the least physically active, the most likely to smoke, and the least likely to take a multivitamin (among many other things you can spot directly in the table, including higher BMIs, higher alcohol intake, and a trend towards less healthy non-red-meat food choices). Although the researchers tried their darnedest to adjust for these confounders, not even fancy-pants math tricks can compensate for the immeasurable details involved in unhealthy living, the tendency for folks to misreport their diet and exercise habits, and whatever mild insanity emerges from trying to remember every food that hit your tongue during the past year.

And in case you didn’t spot them yet, our magical table has two particularly ogle-worthy things. The first one’s this:

If you had any doubt that people fib on food questionnaires, this should put your mind at ease. Take a look at the average (reported) calorie intake for the women in the first quintile of red meat consumption. Yes, that does say “1200 calories.” Yes, that is low enough to make most people wake themselves up at night as they unconsciously gnaw on their own arm in a quest for nourishment. And the red-meat-avoiding men aren’t much better, clocking in at a bit over 1600 calories for fully-grown adults. If there really is an 800-calorie gap between the folks with the lowest and highest red meat consumption, there’s obviously something much more significant going on in their diets than the color of their chosen animal foods. And if—in a much more likely scenario—there’s some major mis-reporting going on, that only bolsters the notion that we shouldn’t trust food frequency questionnaires any farther than we could throw ‘em.

Here’s the other ogle-worthy thing:

Ah, yes: here we see the folks eating the least red meat have the highest rates of elevated cholesterol, while the red-meat-indulgers have the lowest rates. Given the media’s eagerness to assign cause and effect to this study, it’s mighty strange none of the headlines proclaimed “Red meat reduces cholesterol!”

So What About This Death Stuff?

For those of you who hoped this analysis would completely obliterate any link the researchers found between red meat and “dying prematurely,” here’s the anticlimactic part. In the context of what’s ultimately wobbly, imperfect, and tragically inconclusive observational data, the researchers did find that the folks reporting the highest intake of red meat had slightly elevated rates of death from cardiovascular disease, cancer, and total mortality (though as we should know by now, correlation isn’t causation!). After adjusting for age and the other documented confounders, the association went down but didn’t disappear completely. (If you like staring at numbers, you can take a gander at the tables for all-cause mortality, cardiovascular disease mortality, and cancer mortality to see how death risk changed between quartiles and with various statistical adjustments. And you can check out the lovely Zoe Harcombe’s parsing of the study if you’re craving an even geekier data safari.)

But there’s still more to the story.

Those numbers thrown around in the fear-mongering news clips—20% increased risk of death from all causes for processed meat and 13% increased risk of death from all causes for unprocessed meat—are classic examples of how even the most ho-hum findings can sound dramatic if you spin them the right way (and remember to attribute them to Hahhh-vard). If your risk of dying from a particular disease is 5% to start with, a “20% increased risk” only bumps you up to 6% in the grand scheme of things. That’s a lot less scary. Especially when delectable foods are involved.

Lessons From the Past

In case you’re skeptical that observational studies can run disturbingly contrary to reality, look no further than the hormone replacement therapy (HRT) craze that peaked a few decades ago. By 1991, 30 observational studiesincluding this one based on none other than the Nurses’ Health data—collectively showed that women taking estrogen seemed to have a 44% reduction in heart disease risk compared to their non-hormone-replacing counterparts. Naturally, this led literally millions of women to jump on the estrogen bandwagon in pursuit of better health and longer lives. A very unfortunate oopsie-daisy sprouted up later when some randomized, controlled trials finally emerged and revealed that rather than being protective, hormone replacement therapy actually increased heart disease risk by 29%!

Just like we see with red-meat avoiders versus red-meat indulgers, these observational studies showed that women using hormone therapy generally had healthier lifestyles than women who weren’t—including smoking less and exercising more. Their good lifestyle habits obscured the true effects of taking hormones, just as meat eaters’ bad lifestyle habits might obscure the true effects of eating red meat. Are we sure that a similar risk ratio flip-flop wouldn’t happen if we moved away from observational studies of meat consumption and towards infinitely more reliable randomized, controlled trials?

Until we actually have some studies like that, it’ll be impossible to know—but if history has any say in the matter, it’s a strong possibility. And while we patiently twiddle our thumbs waiting for those well-designed meat studies to start existing, we should keep in mind that humankind has survived a pretty doggone long time—in much more robust shape than most of us are today—without carefully swapping our lamb shanks for an equivalent serving of kidney beans.

Does Red Meat Make Bad Things Happen?

Since the very dawn of the taste bud, it seems red meat has been shrouded in mystique and evilness. Although the crumbling foundations of our anti-saturated-fat beliefs have partially redeemed meat and restored its throne on the dinner plate, red meat hasn’t quite escaped the stigma of being bad, even if we can’t totally pinpoint why. Is there a valid reason to avoid it?

Assuming you’ve nixed nitrite-laden processed meats and seek out higher-quality animal parts, one of the biggest legitimate dangers with red meat has more to do with preparation methods than the meat itself. High-temperature cooking—like pan-frying or grilling to the point of well-doneness—can create mutagens called heterocyclic amines (among other nefarious compounds) that may potentially contribute to cancer. Although the research here isn’t totally conclusive yet, it’s probably wise to stick with gentler cooking methods as often as possible (or better yet, learn to love steak tartare).

In Conclusion

Although the wildfire-esque media coverage of this study is enough to make any omnivore feel like punching Al Gore for ever inventing the internet, it’s actually a great opportunity to test our critical thinking skills and explore the unending deficiencies of observational studies—including the self-reported data they’re often built from. We might not emerge with any newfound health guidance after breaking down bad science, but it’s always nice to have a better understanding of what the tumultuous world of research is really saying.

And with that, our latest installment of Science Says Meat Will Kill You has come to a close. But worry not: this is just the beginning of an exciting new season of food drama. Will the butter defeat the margarine in their upcoming oil-wrestling contest? Will the asparagus discover who really killed her uncle’s stepdaughter’s boyfriend’s roommate’s poodle’s groomer? Tune in next week to find out!*

*Episode may or may not actually air

You want comments? We got comments:

Imagine you’re George Clooney. Take a moment to admire your grooming and wit. Okay, now imagine someone walks up to you and asks, “What’s your name?” You say, “I’m George Clooney.” Or maybe you say, “I’m the Clooninator!” You don’t say “I’m George of George Clooney Sells Movies Blog” and you certainly don’t say, “I’m Clooney Weight Loss Plan”. So while spam is technically meat, it ain’t anywhere near Primal. Please nickname yourself something your friends would call you.

  1. Jon – if you want a vegan lifestyle great ! If you have a problem with the feedlots and other ways animals are mistreated … Great , so do I. Don’t make nutritiona judgements based on that. Any diet where you need to supplement something (like.b12) is not a complete diet. Maybe we are not designed to eat red meat everyday, but we are ment to eat meat. Again, looking at our digestive tracks and teeth, one can debate that it may be only a small amount , but as I wrote earlier , the first humans would have never chosen to eat meat if it was unhealthy.

    Andy wrote on March 16th, 2012
  2. Sorry , accidently hit send to soon.
    I have many friends who have very different diets . If being vegan , or vegetarian works for you, you feel great and check out healthy with your doc , that is awesome. I eat a lot of local farm raised meat, fish , pork , and chicken. I balance it with lots of vegetables, fruits and oats. Unless my doctor and mirror is lying , I look and feel lean and healthy.
    Do what works for you , but keep ideology out of nutrition. I think the most glaring problem is the way these reports are presented by the media . Using words like death in the headlines naturally will cause concerns , and unfortunately, these headlines are the only thing many people really read.

    Andy wrote on March 16th, 2012
  3. I suggest you all go over to read Gary Taubes’ excellent response to this study. No matter how much lipstick you slather on this pig, it still says “Oink”.

    John wrote on March 16th, 2012
  4. “the great thing about science is that it is true whether you believe it or not .”
    It was considered truth , punishable by death or imprisonment once , that the world was flat. It was a fact for a long time that we had nine planets. Margerine was healthier than butter. We are constantly learning , and scientific “truths” or “facts ” change all the time. There are very few absolute truths in science.

    Andy wrote on March 16th, 2012
  5. It’s just the vegetarians trying to scare us meat eaters. I don’t bother paying attention to those studies, just my doctor :)

    Richard wrote on March 16th, 2012
  6. A very interesting study. It seems that four major variables were strongly correlated with heavy read meat eaters.
    1) Lack of excersise
    2) Lack of vitamin suppliments
    3) Smoking
    4) High calorie intake.

    Did this study measure the real causitive reasons for premature death or spurious correlation. The differences in these variables were significant yet the difference in the premature death rates between low or now red meat eaters and heavy.
    Like the article says this is a precursor and creates a hypothesis. I think its hypothesis is invalid.

    Fred Held wrote on March 16th, 2012
  7. Not sure why anybody ever cites the Nurses’ Health Study. Even quacks like Andrew Weil have sniffed it out for what it is. This post illustrates all the weak points in questionnaires and particularly metadata in any way related to questionnaires or correlation. After seeing Hu’s name in my all my time reading studies online, I know to disregard. ANYHOW; though it was a bit tongue-in-cheeky for my taste, superb article!

    Kiko Rex wrote on March 16th, 2012
  8. TL; DR: This study, while not perfect, is some of the best evidence we are going to get and we should pay attention to it.

    While I think this author makes some good points, I don’t think she fully considers the steps taken in this study to establish causation and minimize confounding variables.

    First, because this study is longitudinal, it is more pseudo-experimental, and can make claims about causation. Because we know the temporal order of events, i.e., people ate meat THEN got sick or not, we know it’s likely not the case that these people were sick anyway or that their sickness somehow led to more meat-eating.

    Second, these samples, NHS and HPFS, are somewhat well known. The whole point of using these samples is that they are homogenous and thus confounding variables are minimized. These people are roughly equivalent in terms of job stress, free time, socioeconomic status, access to health info, etc. Yes, they are not all identical people, but it is a good step in the direction of being able to generalize.

    So yes, one can play the ultimate skeptic with regard to this information, but it is unlikely that the perfect study will ever be conducted where people are randomized to meat eating, vegetarian, organic meat, etc. eating conditions, and followed for this length of time in these numbers. It doesn’t really make sense to me to hold out for the perfect study, rather it makes sense to hedge based on the best available information at a given point in time. That is to say, cut down red meat consumption.

    Jim wrote on March 16th, 2012
    • I’m not sure I agree. I “hedged” for 25 years as a vegetarian based on the best available info at the time – and that was whole grain, high fiber, low fat, etc. and I just got sicker and sicker. Now I eat lots of red meat, veggies and saturated fats and I’m in the best shape of my life, perfect lab values and blood sugar and blood pressure stabilized at new safe levels.

      Melissa wrote on March 16th, 2012
      • Did you eat according to the latest scientific knowledge about diet, or according to the latest – often distorted – presentation of the scientific findings in the media? My guess is the latter, since – unless you are a scientist, it’s hard to gain accept to the scientific literature.

        Today it’s a little easier, using Google Scholar ()http://scholar.google.com/, which I highly recommend. It’s much, much better to get your information from here, than from any media, including this website.

        Stefan wrote on March 16th, 2012
      • Did you eat according to the latest scientific knowledge about diet, or according to the latest – often distorted – presentation of the scientific findings in the media? My guess is the latter, since – unless you are a scientist, it’s hard to gain accept to the scientific literature.

        Today it’s a little easier, using Google Scholar, which I highly recommend. It’s much, much better to get your information from here, than from any media, including this website.

        Stefan wrote on March 16th, 2012
    • I agree.

      Stefan wrote on March 16th, 2012
  9. Thank you for taking the time to research and explain this craziness. I was a vegetarian for over 15 years and it almost killed me. When I began eating meat again, it was miraculous. I ate the right vegetables and took all the proper supplements. I was not eating according to what my body needed. I know how to eat and now know that some people need red meat.

    Dee Ragin wrote on March 16th, 2012
  10. I hope a lot of people will quit eating beef. The price is way up and that would help bring the price down. I buy a half of a cow once a year. I’m lucky because I only have to drive a short way and it’s grass fed/finished. I notice the price of conventional beef is almost as high now as the grass fed.

    big John wrote on March 16th, 2012
  11. Denise Minger, you look extremely cute, but did you ever study statistics and/or philosophy of science?

    Stefan wrote on March 16th, 2012
  12. I would love to tell people that eating Red Meat is a health but it isn’t.

    Ricardo wrote on March 16th, 2012
  13. Thank you for this – when I first read about this “study” my initial reaction was to try to find the truth behind the info, of course MDA brought us the info we needed!

    BTW, my favorite line: “…enough to make any omnivore feel like punching Al Gore for ever inventing the internet…”

    brian wrote on March 17th, 2012
  14. …The key is get the QUALITY …color has nothing really to do with it>>>

    Dave PAPA GROK Parsons wrote on March 17th, 2012
  15. I’m leaning towards a paleolithic diet myself, but I cannot take Denise’s post seriously.
    It’s scary how most of the commenteers here have a preconceived notion about red meat being healthy, and therefore sees Denise’s post as solid, while it’s not. Rather it’s an example of a layman’s misunderstanding of what science can and can’t do.
    I suggest everyone here take a course in statistics, then a course in philosophy of science, and then read the research paper Denise is “dismantling” here themselves. Unless you fail the courses, you will be able to see why this post is rather silly. And this is not a matter of opinion, but the trust of the matter.

    Stefan wrote on March 17th, 2012
    • Stefan,

      I’ve had more than “a course” in statistics, and what Denise has written parsing the study is more viable than than you give her credit for. Observational studies are notoriously subject to observer biases and reporting error, to say nothing of the uncontrolled and/or untested variables which can often have a greater association to the results that the specific entity they were looking at. While observational studies can often provide an interesting starting point to develop a theory which can then be tested in a truly scientific fashion, they certainly aren’t reliable enough to make sweeping and generalized determinations like “Red Meat Can Kill You”. There are simply too many places for statistical error to creep into the final results. Even if the observers were pristine in their motives and methods and the self-reporting study participants were scrupulously honest and accurate (neither of which is 100% likely), the MOST that can be drawn from a study such as this, is an association between the factor(s) being studied and the result. A huge chasm exists between “association” and “causation” or even “risk”.

      Montie wrote on March 17th, 2012
      • Montie, you are absolutely right, saying “Red Meat Can Kill You” would be a mistaken generalization. But the study never said that. Did you actually read the study, or only the hyped misrepresentation of it in the media?

        Here is the summary of the study, in the words of the scientists, not a silly journalist:

        Red Meat Consumption and Mortality
        Results From 2 Prospective Cohort Studies

        An Pan, PhD; Qi Sun, MD, ScD; Adam M. Bernstein, MD, ScD; Matthias B. Schulze, DrPH; JoAnn E. Manson, MD, DrPH; Meir J. Stampfer, MD, DrPH; Walter C. Willett, MD, DrPH; Frank B. Hu, MD, PhD
        Arch Intern Med. Published online March 12, 2012. doi:10.1001/archinternmed.2011.2287

        Background Red meat consumption has been associated with an increased risk of chronic diseases. However, its relationship with mortality remains uncertain.

        Methods We prospectively observed 37 698 men from the Health Professionals Follow-up Study (1986-2008) and 83 644 women from the Nurses’ Health Study (1980-2008) who were free of cardiovascular disease (CVD) and cancer at baseline. Diet was assessed by validated food frequency questionnaires and updated every 4 years.

        Results We documented 23 926 deaths (including 5910 CVD and 9464 cancer deaths) during 2.96 million person-years of follow-up. After multivariate adjustment for major lifestyle and dietary risk factors, the pooled hazard ratio (HR) (95% CI) of total mortality for a 1-serving-per-day increase was 1.13 (1.07-1.20) for unprocessed red meat and 1.20 (1.15-1.24) for processed red meat. The corresponding HRs (95% CIs) were 1.18 (1.13-1.23) and 1.21 (1.13-1.31) for CVD mortality and 1.10 (1.06-1.14) and 1.16 (1.09-1.23) for cancer mortality. We estimated that substitutions of 1 serving per day of other foods (including fish, poultry, nuts, legumes, low-fat dairy, and whole grains) for 1 serving per day of red meat were associated with a 7% to 19% lower mortality risk. We also estimated that 9.3% of deaths in men and 7.6% in women in these cohorts could be prevented at the end of follow-up if all the individuals consumed fewer than 0.5 servings per day (approximately 42 g/d) of red meat.

        Conclusions Red meat consumption is associated with an increased risk of total, CVD, and cancer mortality. Substitution of other healthy protein sources for red meat is associated with a lower mortality risk.

        . . .

        As you can see, the researchers are not the ones making bold claims like “Red Meat Can Kill You”.

        Stefan wrote on March 17th, 2012
    • Stefan wrote: “I’m leaning towards a paleolithic diet myself”

      Cool, what do you find most impressive about Paleolithic diets?

      Paleophil wrote on March 19th, 2012
  16. I am still curious if anyone has done a causative study (or knows of one) that links eating red meat with cancer. I have heard all the hype about the “China Study”, but isn’t that also an observational study?

    Debbie Abeyta wrote on March 17th, 2012
  17. when i stopped eating meat and allowing traditionally prepared grains and legumes into my diet, my acne went away and my energy levels increased. when i started eating meat or other animal products again, my acne came back. I take this as my body telling me that meat isn’t good for me. just sayin…

    Michael Seiser wrote on March 17th, 2012
  18. Can I recommend this response by the UK Soil Association (organic accrediting body)?
    http://www.soilassociation.org/news/newsstory/articleid/3170/us-red-meat-study-soil-association-response

    Norma wrote on March 18th, 2012
  19. Who did this study? Someone from the fishing industry perhaps…

    Heather wrote on March 18th, 2012
  20. Thank you fir sharing this!!! Very true!
    Funny thing about all this hype is what about sugar? Has anyone read about or heard the facts on what sugar is doing or causing? Im a little more concerned about alien viruses in my food than eating red meat. I need the iron. I will not stop eating it. I know better!

    Bobbie Degand wrote on March 18th, 2012
  21. Excellent analysis and break down. I’ll be pointing several people to this link in the weeks and possibly months to come.

    Jody Ruttan wrote on March 18th, 2012
  22. My scientist trained husband has taught me to be so careful about correlation and causation. He constantly reminds me, “Correlation does not prove causation.” And it’s very concerning to me how many blogposts and news articles I read (some well meant, others just wanting to prove a point) where they base everything on a correlation. I also find it very disturbing that a study from Harvard, of all places, is purporting truth and “scientific evidence” from a basic observational study–breaking some of the most basic scientific principles, such as correlation doesn’t prove causation and generating evidence from an observational study, as you wisely pointed out. It’s frustrating and also quite sad! It seems like desire for prestige or moments of fame or certain agendas have taken over the desire for truth to be well-researched and known. And lumping all red meat together like that…goodness! I don’t believe for a moment that the homemade hamburger I ate (made from beef from organic, grass-fed cows that came to me straight from the farm) is going to negatively affect my body in the same way as a fast food hamburger with its poor quality beef and loads of additives. IF they actually PROVED scientifically that red meat did indeed increase our risk for diseases, my first question would be is it red meat…or is it the antibiotics and hormones in the meat? the corn the cows are fed? How about a no-hormone/antibiotic/pesticide grass-fed red meat vs. conventional (with whatever antibiotics/hormones are commonly used) corn-fed red meat study? I’d love to see a quality research study done on that! We already know the make-up of the meats are different, so chances are they affect our bodies differently.

    Christy wrote on March 18th, 2012
    • Christy wrote: “IF they actually PROVED scientifically that red meat did indeed increase our risk for diseases…”

      If your husband had taught you better, you would know that science cannot prove anything. Science can only disprove. I recommend reading Popper to begin with. Some key terms to understand is falsification, the demarcation problem, and the problem of induction.

      Stefan wrote on March 18th, 2012
      • You might seem a little more credible if you actually had a criticism that could be evaluated. You claim just one stats course and one philosophy of science class and voila, you can tell the work is shoddy. I call bullcrap. If you can point out the flaws in meaningful detail (not generalized crap that means nothing), I’m all ears. Until then, you are just flapping your gums and moving air saying nothing.

        Mario Vachon wrote on March 20th, 2012
  23. As a budding social scientist I find the information on how bad science is done to be much more meaningful that the red-meat-is-the-death-of-us-all clap trap.

    Ben wrote on March 18th, 2012
  24. noone distinguishes betweeen grassfed grassfinished meat and commercial meat, pasdtured eggs and butter and non pastured, organic vegetables and fruits and non organic, excluding glutens and nightshades if theis is a problem for you, and excluding or including excitotoxins. Unless a study distinguishes betwen these they are actually not testing anything. Too many confounding variables

    marilyn wrote on March 18th, 2012
  25. Too funny… I too just wrote about this same thing. I took an article from a friend titled “Why Become A Vegetarian” ( at http://aloe1.com/index.php/blog ) and contrasted it with a meat eaters response. Of course, discussing the great referenced research was necessary. But your critique of the study results was much more thorough. Thanks.

    Dr. Michael Haley wrote on March 18th, 2012
  26. “If your risk of dying from a particular disease is 5% to start with, a “20% increased risk” only bumps you up to 6% in the grand scheme of things. That’s a lot less scary. Especially when delectable foods are involved.”

    I ask, what is a 5% risk? 5% of what? Say I’m 50. So what are my chances of dying tomorrow, or this year or next year? I honestly don’t know. So the unknown chances are increased 20%. What exactly does that translate into?

    Moreover as someone said, I enjoy certain foods. All of them pose risks: salmonella from fowl, mercury from fish, E coli from vegetables. Where does all this fear and loathing end?

    John 3rd wrote on March 18th, 2012

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