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

Will Eating Whole Grains Help You Live Longer?

happywomaninwheatWe interrupt our regularly scheduled Friday Success Story to bring you a timely and critical look at this week’s Hottest Health Headline. And who better to tackle the research in question than expert study-dismantler Denise Minger? You may remember Denise from the recent article she wrote for MDA in which she went toe-to-toe with a study linking a high fat diet with breast cancer. Today she takes on our nemesis, our foe, our mortal enemy – the Whole Grain. And now, Denise…

A headline-grabbing study just hit the press, and on the surface, it looks like a home run for team Healthy Whole Grain. This chunk of research – officially titled “Dietary Fiber Intake and Mortality in the NIH-AARP Diet and Health Study” – followed a pool of over half a million adults and found that, across the board, the folks eating the most fiber had lower rates of death from almost every disease. But here’s the kicker: The only fiber that seemed to boost health was the kind from grains. Not veggie fiber. Not fruit fiber. Just grains, grains, grains.

Suspicious, eh?

I thought so too – but the findings are pretty robust. Compared to the folks who skimped on grain fiber, those eating the most of it had lower risk of death from:

  • all causes (22% lower for both men and women)
  • heart disease (24% lower in men, 34% lower in women)
  • cancer (17% lower in men, insignificant for women)
  • infectious disease (56% lower in men, 59% lower in women)
  • respiratory disease (31% lower in men, 46% lower in women)
  • rabid jackalope attack* (42% lower in men, 39% lower in women)

*Figures derived from my personal research; not yet peer-reviewed

By contrast, veggie fiber had only modest-to-neutral associations with mortality, and fruit fiber didn’t have any effect at all – except for a slightly positive relationship with death from infectious disease. (Oops! Maybe an apple a day actually lures the doctor closer.)

For those of us living gleefully grain-free, this study is a real head scratcher. At the very least, it’d seem like the fiber in vegetables – coupled with all their other protective substances – should be decent competition for whole grains, but clearly that isn’t the case. What’s going on here?

As usual, there’s more to the story than what the media regurgitated. Let’s dive in and see what this study really uncovered. It’s actually pretty interesting.

Red Flag #1: Confounder Attack

Lucky for us, the researchers managed to record some potential confounders – those sneaky diet and lifestyle factors that easily skew the outcome of studies like these. And confounders there were! Here’s a graph showing the major differences between the folks eating the most grain fiber and those eating the least:

grain graph

If this doesn’t scream “people with healthy lifestyles choose whole grains,” I don’t know what does. The fiber-lovers were almost twice as likely to be vigorous exercisers (working out more than three hours a week), were much less likely to smoke, had lower intakes of alcohol, and were generally more educated than those with the lowest fiber intake. And we can see that the folks loading up on grain fiber were also cutting back on red meat – showing for the 80- or 90-billionth time that health-conscious people tend to be phobic of certain animal foods. (But that’s a story for a different day.)

Indeed, after the researchers adjusted for their battery of confounders, the protectiveness of grains diminished considerably. Before adjusting for anything, grain fiber was linked to a 47% lower risk of death from all causes – but after accounting for variables like smoking, drinking, and exercise habits, the risk reduction whittled down to only 22%. Ditto for mortality from individual diseases. In fact, because I’m such a graph-o-phile, here are two more showing how dramatically the risk reduction shifted as soon as the researchers corrected for various lifestyle factors. The vertical numbers represent the lowered mortality risk (in terms of percentage) associated with grain fiber – the higher the number, the greater the risk reduction:

men mortality

women mortality

Check that out! From these graphs, we can see that those wily confounders inflated the true effects of grain fiber. In fact, for women, the link between grain fiber and cancer mortality tapered off into insignificance as soon as the researchers improved their statistical models.

Of course, grain fiber still came out looking protective against most diseases – but keep in mind that it’s virtually impossible to account for the smorgasbord of changes people make when they shift towards a healthier lifestyle. The take-home point is that eating whole grains is ridiculously tangled with other health-conscious behaviors. It’s not a stretch to imagine that if the researchers had also adjusted for things like trans fat, vegetable oil consumption, and processed carb intake that the risk reduction from grain fiber would’ve slid even closer to nil.

Except, of course, for that odd relationship with infectious disease – which didn’t budge even after correcting for confounders. Which brings us to…

Red Flag #2: Fiber Protects Against Infection?

When I first perused this study with my Skeptic Hat on, the first thing that caught my eye was the steep correlation between grain fiber and reduced death from infectious disease – a stronger connection, in fact, than fiber had with any other mortality variable. That’s pretty cool, but it makes no sense. So I was curious to see how the researchers explained it in their paper:

“Inflammation, a predominant pathphysiologic response in many infectious and respiratory diseases, has been suggested to contribute to the progression of these diseases. Studies have shown that dietary fiber has anti-inflammatory properties. … The anti-inflammatory properties of fiber could explain, in part, significant inverse associations of dietary fiber intake with infectious and respiratory diseases as well a with CVD death.”

Ah, so they’re playing the “inflammation” card. Fair enough. Unfortunately, it doesn’t explain why fruit and vegetables – which, if anything, are more anti-inflammatory than grains – barely put a dent in disease risk in this study. In fact, the researchers’ Inflammation Proclamation makes their findings all the more puzzling.

My money’s on a different possibility: that the researchers failed to account for poor living conditions and socioeconomic status, both of which are huge contributors to infectious and respiratory disease. It’s well known that folks with lower income and social status also tend to have less healthful eating habits – including a lower consumption of fiber – and also have higher mortality from almost every cause. So rather than underscoring some magical pathogen-fighting properties of grains, this study’s link between grain fiber and reduced infectious disease is probably a symptom of some straggling, non-adjusted-for confounders. Dur.

The Grainy Seesaw

Apart from massive confounding, this study poses another interpretive problem as well. When people hike up their intake of whole grains, it’s not usually a matter of sprinkling wheat bran on their morning danish or chasing a Wonder Bread sandwich with a bowl of oatmeal. Instead, it’s an act of swapping: Folks reach for the whole-grain loaf instead of the white bread; they stir-fry brown rice instead of polished; they ditch the Froot Loops, get adventurous, and buy a special “regularity” cereal with 28 grams of fiber per serving (and then spend the rest of the day looking like an inflatable pool toy).

Heck, even the USDA – in its infinite nutritional wisdom – emphasizes that whole grains should replace refined grains instead of just dogpiling on top of them. Straight from the horse’s mouth: “It’s important to substitute the whole-grain product for the refined one, rather than adding the whole-grain product.” (If the USDA says it, you know they mean business.)

As a result, eating more whole grains (and grain fiber) inevitably goes hand-in-hand with eating fewer refined grains. And this is precisely what makes grain studies so squirmy and misleading: Measuring the effects of whole grains indirectly captures the effects of refined grains, too, and they’re hard to untangle.

So how do we wade through these webs of correlations and determine what’s really going on? Studies like the recent National Institutes of Health don’t offer a lick of help – epidemiology is notoriously sucky. Fortunately, we don’t have to look too far to find something more informative. A number of Healthy Whole Grain studies actually show that limiting refined grains is just as beneficial – if not more so – than increasing whole grain intake. For example, take a gander at this 2005 study analyzing the grain-noshing habits of over 800 men and women. As we might expect, the folks eating the most whole grains fared the best, while those eating the most refined grains had higher risk markers for disease. No news there. The researchers concluded: “Whole-grain intake is inversely and refined-grain intake is positively associated with the risk of having metabolic syndrome. Recommendations to increase whole-grain intake may reduce this risk.”

Same old, same old. But what the researchers don’t discuss is the intriguing trend that surfaced in one of their tables (viewable here). If we compare the folks who ate the most whole grains (at least 143 grams per day) with those who ate the least refined grains (less than 125 grams per day), the health perks are nearly identical – with the high-whole-grain group actually coming out less favorably in some cases. Compared to those who ate the least amount of refined grains, the abundant-whole-grain group spawned a greater percentage of folks with high triglycerides, low HDL, high LDL, hypertension, and metabolic syndrome. Yowza!

So what does this pattern tell us? For one, that scooting the refined grains off your plate may be more health-protective than eating more whole ones. And that, indeed, the alleged health benefits of whole grains could simply be due to eating less of their refined counterparts.

Of course, this isn’t the only study to unearth this sort of trend. If you’re in a Nerd Safari mood, hop over to this study to read about the lack of benefit whole grains have on inflammation and insulin sensitivity, or this study (PDF) to read about how a diet supplemented with wheat bran caused a slight rise in triglycerides and oxidized LDL. When you do a some digging, you’ll see the evidence supporting Healthy Whole Grains is surprisingly wobbly.

Why Whole Grains Are Only Half the Story

Grains are such an ingrained (pun definitely intended) part of our food culture that, in studies, the question is usually “Which form of grain is best?” instead of the more pertinent query, “Do we even need these lectin-filled suckers in our diet to begin with?”

The first question brings us swarms of studies that ultimately act as yes-men to the Whole Grain King. Yes, Whole Grain, you are superior! Yes, Whole Grain, you’re so much more handsome and charming than your nemesis Refined Grain. Yes, Whole Grain, you deserve praise and prominence in the USDA’s new dietary guidelines. Shall we massage your endosperm to celebrate?

But if we took an honest look at the second question, current research would veer in a much more interesting direction. Instead of tinkering around with the effects of rye versus wheat or frosted versus unfrosted Corn Flakes, we’d be comparing grain-filled diets with totally grain-free ones – in turn helping us discern, with cold hard science, whether whole grains are truly beneficial or simply less harmful than uber-processed forms.

Do grains contain some valuable nutrients? Absolutely. But so do tree bark, grass, twigs, and other foods that don’t jibe with human physiology. It’s not surprising that diets including whole grains result in better health outcomes than diets rich in refined grains, but that doesn’t mean they’re an optimal choice – just the lesser of some other Neolithic evils.

But back to our study du jour for a moment. Regardless of its findings, keep in mind that this research is correlative. All it does is say Thing One gets higher or lower in relation to Thing Two (in this case, grain fiber and various diseases). There’s no way – none, nada, zilch – to determine whether the relationship is accidental or truly cause-and-effect. The journalists who reported otherwise were being sloppy. Shame, journalists! Shame.

All in all, this is just one more drop in a tumultuous, misinterpreted sea of Healthy Whole Grain studies. If you want to stay afloat, I recommend using that fiber for building your boat instead of filling your stomach.

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. Great post! I’m 100% sure I’ve got Celiac, plus wheat is on the list of foods related to a latex allergy I have. Even if I didn’t have those reasons to avoid wheat/grains – whole or otherwise, I would think twice. I’ve shared this with those I care about. I’m printing it out for my weight-loss group, too.

    Melissa Fritcher wrote on February 18th, 2011
    • Just found out yesterday that a very small amount of gluten can affect the body for up to six months in people that are sensitive. uhg.

      Karen wrote on February 19th, 2011
      • Do you remember where you read that, Karen? I am not officially diagnosed but am certainly ‘gluten-sensitive’ and would be interested to read more about how long it affects your body. I’ve kicked wheat (and grains) out of my daily diet but occasionally indulge in small amounts.

        Abigail wrote on February 20th, 2011
  2. Thanks for the breakdown! When did science artifically inseminate the PR department? Their spawn are so frustrating!

    The fact remains that, even if whole grains offer health benefits, those benefits are irrelevant for celiacs, the allergic, the wheat intolerant, diabetics, and all the other people I’ve read about on MDA, who quit grains and helped their arthritis, back pain, migraines, etc, etc.

    fitmom wrote on February 18th, 2011
  3. Very interesting!Its nice that Denise has the time (and the know how) to pull apart these studies. This post just gives me yet another reason to shun grains so I can eat more delicious bacon, salads, eggs, and other primal foods.

    Anika wrote on February 18th, 2011
  4. I love Denise.

    Brendan wrote on February 18th, 2011
    • We all love Denise. We should end Roses.

      DavidB wrote on February 18th, 2011
      • Oops. Maybe SEND instead.

        DavidB wrote on February 18th, 2011
  5. Whole Grains — The lesser of two evils. Love that! That, to me, perfectly, succinctly sums up the thought that whole grains are healthy, when they’re probably just being substituted for something worse, but aren’t really.

    Thedo wrote on February 18th, 2011
  6. I don’t understand your paragraph about grains and infectious diseases.

    Your graphs of risk reduction (men and women) for infectious diseases show roughly the same risk reduction numbers (55 for men, 60 for women) for each of the two groups (low fiber and high fiber with grains).

    This looks like it is showing a 55-60 risk reduction regardless of what you are eating. (low or high fiber). Unless I’m missing something, none of that makes sense at all. You can eat whatever you want and achieve a reduced risk factor vs the “common man” for infectious diseases.

    Please explain.

    Marc S wrote on February 18th, 2011
    • Sorry for the confusion! The last two graphs aren’t comparisons between low fiber and high fiber groups — they both show risk reduction for the people with the highest grain fiber intake, before and after adjusting for confounders. The association with grain fiber and infectious diseases didn’t budge even when the researchers accounted for smoking, drinking, exercise, etc., even though it changed for all the other mortality variables.

      Denise Minger wrote on February 18th, 2011
      • And just to further clarify, all the reduced-risk numbers are calibrated against people with the lowest fiber consumption in the sudy, not necessarily the “common man.” So 22% lower risk of all-cause mortality, for example, means that the folks with the highest grain fiber intake had 22% lower mortality than the folks with the lowest grain fiber intake.

        Denise Minger wrote on February 18th, 2011
        • Cool, thanks for the clarification. I’m not familiar with the medical publishing world, but it would probably be helpful to label the y axis as well as use different colors for graph 1 vs 2 and 3. Blue and red were previously used for low and high fiber groups.

          Cheers,

          Marc

          Marc wrote on February 19th, 2011
  7. Denise, want to come write my school papers for me? I can never dissect scientific papers with this kind of thoroughness!

    Caitlin wrote on February 18th, 2011
  8. But I’m confused about one thing… she says:

    “If we compare the folks who ate the most whole grains (at least 143 grams per day) with those who ate the least refined grains (less than 125 grams per day), the health perks are nearly identical”

    Well, aren’t these two groups probably made up of mostly the same people? If someone eats more whole grains, they probably eat less refined grains, right? And it is likely that the only people who are not in both groups are eating high amounts of BOTH whole and refined grains (assuming they’re not primal), which means they’re eating WAY too many carbs. And what happens when you eat an excess of carbs? You get high Triglycerides, low HDL, etc. What do you guys think?

    Brendan wrote on February 18th, 2011
    • My wording was a little screwy… What I meant to say was that if a subject was in the high whole grain group, but not in the low refined grain group, then they’re just eating a lot of everything, which explains the adverse health effects.

      Brendan wrote on February 18th, 2011
    • That’s a great observation — and you’re right, there are definitely some of the same folks in both groups, since whole grains refined grains tend to displace each other proportionately. The differences in the the percent of folks with high triglycerides, low HDL, etc. between the groups show that there must have been some newcomers in each group, too — enough to sway the blood markers.

      Although it’s possible that some members of the high-whole-grain group were eating the most refined grains too (there isn’t enough data to know for sure), that isn’t the norm in epidemiological studies like this one. The researchers actually divided everyone into quartiles based on grain intake, so there were four groups with very low, low, moderately high, and very high intake of whole grains, and the same for refined grains. As a result, people who weren’t in the “lowest intake” group weren’t necessarily lumped into the “highest intake” group, and vice versa — they may have fallen into the middle groups. (Hope that made sense!)

      The important point is that it seems refined grain intake is just as important, if not more so, in influencing disease risk than whole grain intake. Adding more whole grains (supposedly so wonderful and health-boosting) can’t counteract the damage from refined grains, and probably isn’t the real source of better health outcomes in epidemiological studies, even though the researchers always interpret it that way.

      While I was writing this, I also came across an interesting study comparing the effects of whole-grain sourdough bread vs. white bread, in equivalent amounts. Lo and behold, the whole-grain bread actually *raised* triglycerides, LDL, and apo-B while worsening other cholesterol ratios compared to eating white bread! Full text here:

      http://www.nutritionandmetabolism.com/content/7/1/37

      In the other study, I wouldn’t rule out that whole grains themselves could worsen the health outcomes for some people, regardless of the added burden of refined grains.

      Denise Minger wrote on February 18th, 2011
      • I wonder if it was traditionally fermented sourdough. If it was industrial sourdough, they basically added lemon juice to regular bread dough and did the usual rising and baking. That’s not gonna do diddly to the antinutrients in the grain. Whereas with white bread, a lot of what contained the antinutrients has been stripped away. It’s not the starch (endosperm) that contains all the phytic acid and so on.

        Dana wrote on February 18th, 2011
        • The study says the sourdough bread was “commercially available” and didn’t mention anything about it being traditionally fermented, so my guess is it’s industrial.

          Denise Minger wrote on February 19th, 2011
      • Denise,
        Are the data for this study publicly available? How did you do these analyses? Can you provide a link to this dataset?
        Thanks,
        Ashley

        Ashley wrote on February 18th, 2011
        • Hi Ashley, the study is accessible from the Archives of Internal Medicine (http://archinte.ama-assn.org/cgi/content/short/archinternmed.2011.18). I wasn’t able to find it posted for free anywhere, and right now it’s $30 to purchase — but once it gets indexed by PubMed (hopefully within a few weeks), it might be available through public library systems.

          I did the analyses by simply looking at the numbers the researchers presented in their paper — particularly how the risk ratios changed after they adjusted for the confounders they documented. Nothin’ fancy involved — I didn’t re-crunch any of their numbers, just described their findings without the “whole grains must be healthy” bias.

          Denise Minger wrote on February 19th, 2011
  9. Whole grains are high in phytic acid which does get into the blood stream. Phytic acid has the uncanny ability to chelate Iron (as well as ALL other minerals in your body) and this MIGHT offer an antibiotic effect in terms of fending off infectious diseases. Still, I don’t touch the stuff even if I’m starving.

    Luis wrote on February 18th, 2011
    • Nuts are also high in Phytic acid, some higher than grains.

      Adam wrote on February 10th, 2013
  10. Yeah – I think anybody adhering to this website and lifestyle, need little convincing that grains are far from a ‘health’ food.

    Now – how about tackling a real problem out there:

    I train athletes for a living (great job) and one thing I keep hearing from these collegiate athletes that come back to me in the summers: “We are told to drink CHOCOLATE MILK after training, because it helps us to recover.”

    YIKES…..are you kidding me!!!! Kind of like the “carb loading myth’. Awful advice for these young athletes!!

    Ed wrote on February 18th, 2011
    • Actually, that’s not really a myth, although it is awful advice. Fructose replenishes glycogen stores in the liver faster than any other carb source. (See “Sugar: The Bitter Truth,” a great video lecture from Dr. Lustig of UCSF.)

      Yet another reason why being an elite athlete does not necessarily mean perfect health.

      labbygail wrote on February 18th, 2011
      • Mostly good for replenishing fat storage per the insulin response. Glycogen is usually depleted after 12 seconds of maximum effort – thus replenishing glycogen has little bearing on most sporting activities, except maybe 100 meter sprinters.

        I trained an elite level female soccer player that weighed 160 lbs, after following the ‘chocolate Milk’
        advice of her ‘strength coach. And believe me, she was FAT. After getting her off the poison for 3 months – she was down to a ripped 135.

        But you are right – being an elite athlete, does not always equate to ‘healthy’.

        Ed wrote on February 18th, 2011
        • wtfruit are you spouting off about here?

          Total calorie intake is what matters here.

          Rhys wrote on February 18th, 2011
        • Rhys, you’re wrong. It’s not about calories at all. It’s about what kind of calories you’re taking in. I take it you haven’t looked at the Primal Blueprint 101 posts; I suggest you start there.

          Griff wrote on February 18th, 2011
    • I think that little “gem” has been floating out there since Joel Stager’s study at IU in 2006.

      http://www.indiana.edu/~rcapub/v29n1/milk.shtml

      Naptown Girl wrote on February 22nd, 2011
  11. As a University Statistics teacher, I will be sharing your analysis with my class.

    This is exactly the way I want my students to approach studies when they are released.

    Thank you.

    Frank wrote on February 18th, 2011
  12. If confounders related to healthy lifestyles inflated the association with whole grains, why was there no similar effect on the association with fruit and vegetables? Healthy people eat more fruit and vegetables as well as whole grains.

    This lack of effect makes it unlikely that the “healthy lifestyle” confounder effect and explain the results of this study.

    Tim wrote on February 18th, 2011
    • Good question, this should also be addressed by the author (of the MDA article).

      Marc S wrote on February 18th, 2011
    • I think the idea is that most people don’t actively avoid grain sources of fiber.

      So under CW, anybody whose primary fiber source is fruit and vegetables is generally going to be somebody who isn’t focused on getting fiber — and therefore isn’t super health conscious.

      I also doubt the people in that group got nearly as much fiber/fruit/veg in a day as anybody who hangs out around here does. They just fell into that group because they weren’t bothering to eat tons of grains, essentially.

      Jenny wrote on February 18th, 2011
      • Some studies have examined the association between “attention to a healthy diet” and people’s intake of fruits and vegetables or their intake of fiber.

        For example “Healthy dietary habits in relation to social determinants and lifestyle factors.” Br J Nutr. 1999 Mar;81(3):211-20.

        This saw a about the same association for both variables, with people who paid close attention to a healthy diet eating more fiber and also more fruits and vegetables.

        Tim wrote on February 18th, 2011
    • This baffled me as well, and is the main reason the study seems so strange.

      My impression is that the changes in mortality risk were due mainly to the absence or presence of refined grains and had little (if anything) to do with fiber itself. From the full text, whole grains were initially correlated with fruit and vegetable intake, but the researchers adjusted for that in their statistical models — thus isolating the effects of grain fiber (an indirect marker for the absence/presence of refined grains) when fruit and veggie intake was held constant. As a result, the mortality risk ratios show the changes occurring based on refined vs. whole grain intake independent of fruit and vegetable consumption.

      Even though whole grains appear protective based on how the researchers analyzed their data, it would probably be easy to rank folks based on refined grain intake rather than grain fiber intake and show that more refined grain increased the risk of death — perhaps even more convincingly than grain fiber reduced it.

      The relationship between mortality variables and fruits or vegetables was probably neutral because fruits and veggies don’t have the same “whole vs. refined” dichotomy as grains do. For example, you’ve probably never had to choose between eating a whole spinach leaf and a “refined” one before (baby food notwithstanding). And while people tend to swap refined grains for whole ones, not everyone who eats more whole fruit cuts back on “refined fruit” (ie, juice), for instance. So out of all the fiber-containing foods, grains had the strongest potential to create a spectrum from truly hazardous (refined grains) to less hazardous/closer to neutral (whole grains).

      Denise Minger wrote on February 18th, 2011
      • Denise,

        I don’t want to be toooo damn cynical here – but do you ever get the idea that these studies happen 1) because there are funds laying around (or easily obtained via some grant or something and even NEED to be spent)
        2) almost arbitrarily designed so as to simply gather some kind of organized data pool so they can 3) find SOME kind of result that could create a politically-correct headline so the researchers/school/institute can 4) proudly point at yet another hugely publicized study thereby attracting yet more grant money?

        jus’ speculating…

        DaiaRavi wrote on February 18th, 2011
        • Indeed, the need for researchers to come up with results that support prevailing assumptions in order to provide access to future grants is a major biasing factor at all levels, from study design to drawing conclusions. It is also true that a disproportionate number of studies that support the prevailing assumptions are published. If your study challenges them, it will likely not be published, and it will hurt your chances of getting future research money.

          I think the biggest scandal of all is that so many papers report results that is unsupported by the data, and their claims are never examined by peer review or credulous media, because they are hearing what they want to hear.

          We need to find Denise a source of funding so she can do this full time.

          Angela Quattrano wrote on February 19th, 2011
        • Sue wrote on February 20th, 2011
      • This was my initial thought as well, however some similar epidemiological articles (Jacobs, et al 1998; Liu, et al 1999) found that the whole grain effect on coronary artery disease was independent of refined grain consumption. As you mentioned though, it’s impossible to adjust for every confounder out there, so who knows what’s really going on.

        Will wrote on February 20th, 2011
  13. Mark, I teach HS Biology, and I’m considering about using some of what you mention in this post when I teach principles of the scientific method. Very nice indeed!

    John wrote on February 18th, 2011
    • Whoops … I mean Denise. Way to spread the word though, Mark.

      John wrote on February 18th, 2011
    • I’m thinking along similar lines. I teach math and this would be great for a mathematical literacy course.

      Travis wrote on February 18th, 2011
      • It’d also be great for any class that deals with statistical and research methodology. I’m a sociologist, and I try to sneak in the PB information whenever I talk about methods, biases, and spurious correlations.

        Griff wrote on February 18th, 2011
  14. Fab job! And how ridiculous to compare wholegrain eaters with refined grain eaters and say the study shows benefits from eating wholegrains. Eating wholegrains instead of refined grains, yes it does, but that’s all. A real study into wholegrains would have to also compare those eating no grains at all, obviously ;)

    Katherine wrote on February 18th, 2011
  15. Awesome analysis. Almost all the studies, not just in health, but in economics, and everywhere the results are skewed to what the authors want to show us.

    navi wrote on February 18th, 2011
  16. ***”My money’s on a different possibility: that the researchers failed to account for poor living conditions and socioeconomic status, both of which are huge contributors to infectious and respiratory disease.”***

    Poor people are less likely to have insurance and go to the doctor when sick. A simple upper respiratory or bronchial infection, that could have been treated at onset, can quickly turn into pneumonia which can kill you.

    And another thing, correlation is not causation. The people eating less fiber, were therefore consuming more digestible carbohydrates in the form of refined flour. We know that refined flour and sugar cause inflammation.

    Holy confounding variables batman!

    tracker wrote on February 18th, 2011
  17. Jackalopes are the reason I went primal. I need to run fast to escape their wrath.

    Thanks for skewering another “study”.

    Travis wrote on February 18th, 2011
    • the above comment is why this website needs a “like” button…. :-)

      tess wrote on February 18th, 2011
      • ^^like^^!

        Laura Daughenbaugh wrote on July 4th, 2013
  18. I’m curious about the health effects of “ancient” grains like quinoa, amaranth, spelt, etc. I suspect that those would be a little better for you than whole grains and definitely better for you than refined grains. But is a no-grain diet definitely better than one that includes ancient grains? (Forgive me is this question has been answered before. I’m new to being primal and to MDA.)

    jdperkins wrote on February 18th, 2011
    • Quinoa is a seed, not a grain, so it doesn’t have the harmful effects of grains, but has too much carbs, so be wary. On the other hand, spelt, etc. are just other forms of whole grains with all the same problems. Grain-free is best.

      Shawn wrote on February 18th, 2011
      • Thanks, Shawn!

        jdperkins wrote on February 18th, 2011
      • Any seed is going to have a certain level of antinutrients in it because it’s a seed and doesn’t “want” to be eaten. But some seeds are worse than others. You can actually get more of an insulin/blood sugar response to wheat than you would to the same quantity of, say, potatoes.

        Dana wrote on February 18th, 2011
        • I’m not so anti-potatoes anymore as long as grain is removed from the diet.

          Sue wrote on February 19th, 2011
      • what about flour made from chia?

        AFAIK, no gluten, but is it healthy as opposed to just not bad (like whole grains)?

        ben wrote on February 19th, 2011
  19. Journalists report? If you read a handful of the biggest news sources each day you will see that most of the stories are nothing more than regurgitated press releases. Stories are pulled from the wire that is populated with PR, and propogated like little rabbits. There is no reporting or analysis – another myth to be aware of as you Primalize your life.

    HillsideGina wrote on February 18th, 2011
  20. do ya think the USDA would hire Denise as a consultant? (And, when exactly will hell freeze over?)

    THANKS AGAIN Denise – and Thanks to Mark for giving Denise a huge and much-deserved audience!

    DaiaRavi wrote on February 18th, 2011
    • They wouldn’t hire her. She recently wrote a critique of the research they are claiming support current nutritional recommendation showing it is basically crap.

      Angela Quattrano wrote on February 19th, 2011
  21. This is so timely. Just heard about this study on the evening news a couple days ago and I was wondering…

    Catt wrote on February 18th, 2011
  22. Denise, you are a superhero.

    Mountain wrote on February 18th, 2011
  23. because whole grains have a higher percent of fiber, they have a lower percent of digestible carbohydrate. Therefore, eating more whole grain means eating less digestible carbohydrate. Thus, this study simply confirms that eating less digestible carbohydrate reduces your risk of disease. Vegetables have negligible carbohydrate so their contribution to most peoples total fiber and starch intake is so small that it won’t affect risk one way or the other when their signal is drowned out by grain carbohydrates.

    Don Matesz wrote on February 18th, 2011
    • Since grains supply more total carbohydrate than vegetables, shifting from refined to whole grains reduces your dietary intake of carbohydrate more effectively than increasing vegetables. Thus, fiber from grains gets associated with lower mortality because it most effectively reduces total carb intake in the context of a grain-based diet.

      Don Matesz wrote on February 18th, 2011
  24. So I guess another week with no success story? My favorite part of the website.

    hdizzle wrote on February 18th, 2011
    • This was a great bit of information to share with my make-your-own-bread friends, and I’m very impressed with Denise’s ability to break it down. But I’m with “hdizzle”, no more skipping the success stories! I love them. :)

      Nicole wrote on February 18th, 2011
  25. I really appreciate this. I get so tired of my friends saying about my diet: “Well, but whole grains are good for you.” I’m so tired of trying to explain it, even to those who are genuinely curious. My feeling is exactly what Denise says here, that whole grains are only “better” for you if you’re eating lots of refined grains. But once our body breaks them down, there’s just not much difference. Except maybe bigger BMs…
    Thanks Denise! I’m also just so tired of the media not knowing how to interpret research properly. Especially when it comes to dietary research. How can anyone possibly tease out one confounding variable from real conclusions?

    Buttercup wrote on February 18th, 2011
    • Tom Naughton on his Fathead-Movie blog has a great analogy that I’ve used with a little success: people who smoke filtered cigarettes may have a lower rate of cancer than people who smoke unfiltered, but that doesn’t mean filtered cigarettes PREVENT cancer.

      It’s fun to watch the other person get really quiet as they contemplate that one.

      Renee wrote on February 18th, 2011
      • This is a pretty damned-good way to think about it. I CANNOT wait for people to really dig in and use a control group on these studies that completely removes the items in question from the diet. People get stuck in a “everything in moderation” zone and fear completely cutting something out of a diet.

        Neil wrote on February 18th, 2011
        • Don’t hold your breath. That’s not even something they’re considering doing, because they figure they already know the answers to those questions.

          Besides, definitive studies where they control people’s diets are very expensive to run and hard to get compliance of the subjects. The only way to get grain-eaters to give up grains would be to provide them with all the food they would be eating, and it would be hard to keep them on the diet very long even if they paid them a lot of money.

          Angela Quattrano wrote on February 19th, 2011
      • Ooh, somehow I missed that. I’m going to use it from now on. Thanks for the pointer!

        Griff wrote on February 18th, 2011
  26. Why not include the adjusted low fiber results in the chart for comparison? Seems to me they would also be adjusted downward, no?

    cbs wrote on February 18th, 2011
    • All of the low fiber results — both before and after adjusting for confounding — were calibrated at a risk ratio of 1 (neutral), so graphing them would just show a bunch of bars with the exact same length. :)

      Denise Minger wrote on February 18th, 2011
      • Denise can you suggest a book or other reference to learn about pulling apart data as you do.

        Sue wrote on February 19th, 2011
  27. I’m glad we got people like Denise who have the skills and patience to go tear apart studies like that.

    It sure would be interesting to see a study comparing whole grains vs no grains, although I would also like to see a study comparing wheat vs. no wheat since a lot of people seem to think that wheat is the truly evil grain.

    Anyways, in most of those dietary studies, the confounding factors seem to be so many that it’s hard to draw any definitive conclusion from them.

    Kiddi wrote on February 18th, 2011
  28. Amazing….I still can’t get over the Conventional Wisdom crap out there! I actually tried to tell someone what we absolutely did NOT need to eat grains, and they got made at me. I wonder what they think when they see that I am still walking, talking and very much alive in my grain free world! :)

    The Real Food Mama wrote on February 18th, 2011
    • The fact is that most people have an emotional investment in their diet that makes it hard for them to view other diets without feeling challenged. Even people who have been medically diagnosed with celiac, for whom gluten grains are known to be toxic, are constantly pressured by their loved ones to eat wheat.

      The response often heard boils down to “you’re just doing this to annoy me.”

      The level of scientific illiteracy out there is unbelievable. Ignoring that that people around the world seem to do perfectly well on many different diets, most people are convinced that their own continued survival is sufficient proof that their diet is right and all others are wrong.

      Angela Quattrano wrote on February 19th, 2011
    • It’s so ingrained in their idea of a healthful diet.

      Sue wrote on February 19th, 2011
    • That’s pretty much true of everyone out there. Vegans are adamant that you don’t need meat or animal products. Primals are adamant that you don’t need grains or beans.

      Truth is, people are different. For some people vegan diets work (though I’ve known people to get very sick on them). For some people, grains and dairy are a pathway to disease and illness. Others are fine eating them.

      Marcia wrote on February 20th, 2011
  29. The correct answer to this post is that:

    Being one of the whole-grain eaters in this study makes you live longer.

    Scandinavian wrote on February 18th, 2011
  30. I wonder why they haven’t done a study on “healthy whole grains” and osteoporosis or dental health or leaky gut, etc.

    Kim wrote on February 18th, 2011
    • Wikipedia:

      “Currently, a considerable amount of research is being conducted into treatment of these conditions. According to a report from Frost & Sullivan, the total payouts by an alliance of leading pharmaceutical companies for drug discovery contract research in the autoimmune/inflammation segment from 1997 to 2002 totaled $489.8 million, where Eli Lilly, Suntory, Procter & Gamble, Encysive, and Novartis together account for 98.6 percent of payouts by that alliance.”

      Hey look! They’re trying to develop drugs. Doesn’t THAT count?

      Neil wrote on February 18th, 2011
  31. Ed and labbygail,

    My 13yo daughter is a pre-olympic swimmer and they are really pushing the lowfat chocolate milk as the BEST post-workout recovery drink. Can you direct me to info I can take to the coaches to refute this trendy conventional wisdom? And recommend something better?

    Sandra wrote on February 18th, 2011
    • Can you just refuse to drink the milk. I wonder if a protein shake would be better or nothing at all. Or do stuffed at that level need a post-workout drink?

      Sue wrote on February 19th, 2011
      • Stuffed – athletes at that level
        Sorry writing on my iPad and don’t know why stuffed came up.

        Sue wrote on February 19th, 2011
  32. Denise rocks! Awesome post, I saw this on the news a few days back and was shaking my head.

    Gary Deagle wrote on February 18th, 2011
  33. My Rule Number One:

    If I can’t eat it raw, it’s worse refined.

    The foods I eat can be eaten raw, if one so desires: beef, eggs, vegetables, fish. (Yeah, yeah, I know, raw meat and raw fish can have serious pathogens or parasites but if “clean,” they can be eaten raw.) Bacon is refined of course, but when cooked it still fits my menu.

    Phocion Timon wrote on February 18th, 2011
    • Nice rule of thumb.

      Aaron Blaisdell wrote on February 18th, 2011
    • The human digestive system is not evolved to digest cellulose. Cooking makes fibrous vegetables more digestible, so for some vegetables their nutrition is more available when cooked.

      Angela Quattrano wrote on February 19th, 2011
  34. Excellent job Denise!! Can’t wait until your first book comes out. I love your humor mixed in with the factual.

    Sue wrote on February 18th, 2011
  35. Awesome deconstruction, thanks!! I’m new to Primal eating, and soaking up all the info I can get. Whenever new science comes out that doesn’t include socioeconomic and cultural data, the doubts creep in right away.

    Jacquie wrote on February 18th, 2011
  36. Once again, an impressive ferreting out of the evil co-founders. Brilliant.

    Ever consider writing a book on critical thinking, Denise?

    kem wrote on February 18th, 2011
  37. What I get from this study is that it does not make any difference if you go primal or high whole grain. As long as you get exercise,see a doctor yearly and eat,drink and be merry in moderation. You will be golden

    Jack wrote on February 18th, 2011
    • Maybe you should read Denise’s post.

      Dana wrote on February 18th, 2011
    • The study did not consider the question of “grains vs no grains” or “whole grains vs no grains”. It barely supports its own conclusion. Reading more into it is not justified.

      Angela Quattrano wrote on February 19th, 2011
    • golden brown – ie – toasted like a slice of whole wheat wonder bread –

      no read the post and stop grains.

      ravi wrote on September 6th, 2012
  38. Awesome post that I will have to share with anyone who says whole grains are healthy. Its a length one but well worth the read.

    Its unfortunate that studies like this keep making the headline news.

    When is a primal or paleo study going to be done?

    Primal Toad wrote on February 18th, 2011
  39. I’m a Celiac, complicated with serious IBS. There is no way that I’m going back to grains. Since I’ve stopped eating grains I feel better, I look better, my skin is healthy. That’s not even delving into how much better my GI tract feels. Grains are healthy? For whom?

    Karin wrote on February 18th, 2011
  40. Hi,
    Thanks for the great analysis and breakdown of this study. I’m reading more and more blogs and material from the paleo community and I’m starting to worry that I’m not getting a well rounded objective information feed on nutrition. If it is appropriate, can anyone point me to some blogs that might provide similarly sophisticated analysis and criticism of the tenets of the paleo diet and lifestyle? I believe in testing my beliefs from more than one angle.
    Many thanks

    Chris wrote on February 18th, 2011
    • Look up PaNu and Whole Health Source on Google. They are wonderful.

      Dana wrote on February 18th, 2011
      • Thanks Dana, I have seen those sites and enjoy their content, however what I’m looking for are sites that present opposing views with a similar degree of rigour.

        Chris wrote on February 20th, 2011
    • Hi Chris,
      Honestly I haven’t seen this kind of analysis coming from other diet camps. You’ll have the mainstream reporting from which you may be able to get some details, but may still have to look up the study yourself. Or you have the vegetarian/vegan camps that mostly look for studies showing veg is healthier than meat eating or that unhealthy vegans are doing it wrong.

      Try JackNorrisRD.com and DrMcDougall.com if you want to read more about the other side. I don’t think you will find it as compelling though. There may not be a consensus in the nutrition world, but as the consumer you have to look at what makes the most sense and who has the least to lose. That is- much of the science backs up primal type eating, it makes sense because when people try it they feel healthier and primal proponents have little to lose because it’s not tied to industry (like the usda) or an ideology (like vegan).

      Real Food RD wrote on February 18th, 2011
      • Thanks for the references! I’m of the mind that there is more than one way to be healthy and frankly this column and especially its responses set off a bit of a ‘zealosy alert’ and made me think that I need to balance my reading. And don’t kid yourself that paleo doesn’t resemble an ‘ideology’ and that people aren’t cashing in on it (nothing wrong with that if it is honest and virtuous).

        Chris wrote on February 20th, 2011
        • Chris: You won’t find any science that defends the non-paleo way of eating that is as rigorous or as robust. The fact of the matter is, as demonstrated by the article this blog post takes apart, there are no real scientific defenses of CW eating – just dodges and workarounds, statistical game-playing, and “oh, we hope you don’t notice those confounding factors that we conveniently forgot to take into account and which completely invalidate our hypotheses.”

          The reason you might hear zealotry here is because just about everyone who posts regularly to MDA has experienced the benefits of paleo eating, some of us for quite a long time. There’s no comparable set of success stories out there for CW. I know that what we’re doing works. I know that it will work for anyone who tries it wholeheartedly, not half-assed. I get angry when I see people like “smilinggreenmom” continuing to buy into CW bullshit that will eventually give them cancer, heart disease, diabetes, and arthritis.

          Griff wrote on February 20th, 2011
        • Well, you could read Dr. Fuhrman or The China Study. They are both very much pro-vegan, so you are going to find the same amount of “zealousy alert” that you see here. THough in Dr. Fuhrman’s latest book he admits that his studies show that eating small amounts of meats do not adversely affect the health of his subjects.

          I always react with skepticism when some group wants to eliminate a whole food group. Some people can be healthy vegan. Some cannot. Some people have no problems digesting grains, beans, or dairy. Others have MAJOR issues. Overall, I like to look at studies about large groups of people. When I read about the evils of soy and grains, I look at the Okinawans. When I read about how healthy a vegan diet is, I am reminded that not a single “traditional” ethnic cuisine is vegan.

          Marcia wrote on February 21st, 2011
        • brendan brazier’s “thrive”. he’s an ironman athlete who is vegan. he does not touch gluten, corn or soy, though.

          bee wrote on February 22nd, 2011
    • Some recent columns on elite athletes with big money on the line espousing vegetarian eating have made me step back from the paleo diet reading that I’ve been immersed in and remember that there is more than one way to health.

      http://ca.sports.yahoo.com/mma/news?slug=dm-mmavegetarians021711

      http://ca.sports.yahoo.com/mma/news?slug=dm-diets021711

      I also have alot of respect for the long traditions of macrobiotics and chinese medicine which have a key role for grains. The Enzyme Diet is a book by a doctor who has unique first hand experience with diet and health and he advocates grains and reduced meat consumption, it’s not based on science but observation of hundreds of thousands of colons. He stresses freshness of grains and points out that whole grains can oxidize.

      So far, I’ve been incorporating many paleo principles in my diet but I’m not ready to kick all grains to the curb yet.

      Chris wrote on February 20th, 2011
      • I definitely respect the notion that “there is more than one way to health”, in a global sense.
        In the first place, populations evolved in different environments and adapted to different dietary patterns. In the second, global travel means we’re much more “mixed”, genetically speaking, than we would have been as little as a couple dozen generations ago. (And yes, I do understand that there’s not a whole lot of genetic variation, when you consider the size and amount of info on the human genome. Still, genetic variation does exist, and evolution has no endpoint.)

        I liked Dr. McDougall for info on vegan-type diets without the pseudo-religious vegan rhetoric. Two years on a McDougall diet and I lost a lot of fat… but I never at any point felt “lean” or “strong”. I also got kinda nutty– irritable, obsessive, never stopped craving animal fats, and got to the point where I was literally thinking about food all day, every day, which developed and compounded a lovely array of emotional disorders surrounding food intake. That doesn’t mean he’s wrong, period, or that it won’t work for you.

        Also, thinking back on it, it’s interesting to me to note how few “superstars” there were in that community, in terms of people who had lost a significant amount of weight and kept it off, being happy and fully settled into that lifestyle. I can recall only one or two who stood out. Everyone else there seemed to be working very hard to maintain and remind themselves why they were doing what they were doing, and were almost exclusively only there because they wanted to lose weight. The whole “feel” of this community here at MDA is very different. The glorious array of success stories is different (from folks with a great deal of excess weight to lose, to fit, athletic people who get even more-so), and the general feeling of satiety and happiness is different, too. That tells me a lot.

        I guess all I’m trying to say here is that I can read the more sound “opposing” arguments and accept that they have value for some segment of the population. I don’t believe there is “one true way”. But just because I find some of those arguments sound in principle, doesn’t mean I was able to find the principles sound in personal practice. In other words, it doesn’t have to be an either/or for 100% of the global population. You can accept more than one eating pattern as valid in a global sense, but it’s only going to be personal experience that dictates what’s right for you, personally.

        PS: “Chinese medicine”? I loves me some herbalism, am as big a midwife-hugger as it gets, and I recognize that there are plenty of routes to health that don’t require a pill from Merck, but… “Chinese medicine”? China’s rates for just about every health statistic are dismal. You’d be far better put to look at Mexican, or Swedish, or Japanese medicine ;0). No offense intended.

        mixie wrote on March 28th, 2011

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