Health knowledge made personal
Join this community!
› Share page:
Go
Search posts:

Study Claims An Animal-Based Low-Carb Diet Will Kill You–Not So Fast!

Posted Sep 07 2010 6:57pm

Be encouraged, my friends, because despite the negative stigmatism that livin’ la vida low-carb has been receiving over the past few years, we are winning the argument. How you ask? Well, consider this–when the Atkins diet was in its prime of popularity back in the early to mid-2000’s, those in opposition to it said that it was “dangerous” to remove the body’s primary fuel source (carbohydrates) and that consuming fat of any kind is harmful to cardiovascular health. Flash forward now to the year 2010 and there’s a whole new tune being sung by those who have long espoused the conventional wisdom of less fat and calories and more “healthy” carbohydrates like whole grains, beans, and the like. Now they’re conceding that Dr. Atkins was right when he encouraged people to control the amount of carbohydrates consumed (limited to the “good carbs” found in berries and green leafy veggies, etc.) while insuring you get fat in your diet from sources like avocados, nuts, and other sources.

While this may not seem like such a giant leap for those of us who espouse low-carb living as a healthy way of eating, in reality it’s a really big deal. And the acknowledgement of the benefits carbohydrate-restriction brings comes at a time when the low-fat apologists are absolutely giddy with excitement about the results of a new study published in the September 7, 2010 issue of the Annals of Internal Medicine that allegedly proves a meat-based low-carb diet leads to higher rates of cardiovascular disease and cancer-related deaths than a low-carb diet that is vegetable-based (dubbed “Eco-Atkins” ). We’ll get into the curious details of this study out of Harvard momentarily, but does anyone else see what has happened here? No longer are we simply debating the idea of low-carb vs. low-fat–that argument is ancient history now that the high-carb, low-fat crowd has conceded the uniquely fattening properties of carbohydrates that Gary Taubes wrote so brilliantly about in his 2007 masterpiece Good Calories Bad Calories. And perhaps the Taubes effect is responsible for this seemingly sudden change of heart about the negative role of carbohydrates in the diet. With the upcoming release of his more consumer-friendly Why We Get Fat And What To Do About It on December 28, 2010, all I see are good things to come on behalf of healthy low-carb nutrition in the years to come.

However, now they’ve turned their attention to the fat and protein sources of the Atkins-styled low-carb diet–meat primarily–and are hammering away at the point that red meat will somehow kill you faster than if you chose a low-carb diet that includes mostly plants. They tried making this point with this March 2009 study published in the Archives of Internal Medicine , but it didn’t pass the scientific muster or the common sense smell test with those of us who actually looked at the data used by the researchers. This is what I like to refer to as the veganization or more appropriately the “Pollan”ization of livin’ la vida low-carb (named after bestselling author Michael Pollan who famously wrote in his book In Defense of Food for people to “Eat food. Not too much. Mostly plants.”). It seems we are subjected to this kind of nonsense about once a year that makes a big splash in the headlines against a high-fat, meat-based, low-carb diet and this new study is no exception. Look at just a small sampling of the vitriolic and even snarky reporting of this study:

On a low-carb diet? You may live longer if you make it vegetable-based
Daily Buzz: Low-Carb Diets (ahem, Atkins) Show Health Risks
Low carb diets might be deadly
Animal-Based Low-Carb Atkins Diet Increased Risk of Death

And then there’s this “Health Watch” segment on CBS’ “Early Show” (GAG ALERT!)
http://www.comcast.net/ve/1.0/1585691772/420/356

It’s interesting how all of those “good carbs” she demonstrated are perfectly fine for someone following a high-fat, low-carb diet. Foods like almonds, avocados, berries, spinach and more are a great part of livin’ la vida low-carb, but the doctor didn’t mention that at all. And my point about how they’ve conceded the argument that limiting carbohydrates is gaining in popularity is borne out in that survey that showed consumers looking for more low-carb good options now is up over 500%. It’s a good day when you stop and think how much further along in the education process we are now than we were just five years ago…how much further along will we get five years from now. It’s exciting to think about! Now, let’s get to that study!

Lead researcher Dr. Frank Hu , professor of nutrition at the Harvard School of Public Health, wanted to see the “long-term association between low-carbohydrate diet and mortality” since much of the research on this topic is “sparse.” To do that, he conducted a prospective cohort study of 85,168 healthy women from the famous Nurses’ Health Study and 44,548 healthy men in the Health Professionals Follow-up Study free from heart disease, cancer, or diabetes at the beginning of the study. Note that all of the study participants are health care professionals and not necessarily a representative sample of the general population. The female participants were followed from 1980 through 2006 and the male participants were tracked from 1986 through 2006. Dr. Hu and his fellow researchers determined whether the dieter consumed a more animal-based diet with animal sources of fat and protein or a more vegetable-based diet with vegetables as the primary sources of fat and protein based on “several validated food-frequency questionnaires assessed during follow-up.” However, the researchers acknowledge that portions of the “self-reported diet” could have been “inaccurate.” More about that in just a moment.

In total, there were 12,555 deaths in the women and 8678 deaths in the men during the study period. Approximately twice as many of the women died from cancer (5780) than those who died from a cardiovascular-related issue (2458). Of the men in the study, the death rates were nearly the same between cancer (2960) and a cardiovascular-related issue (2746). Interestingly (and I didn’t read this reported anywhere), the animal-based low-carb dieters in the study were “more likely to be current smokers” which could have just as easily contributed to the deaths found in the study more so than the diet. However, those who ate the more plant-based low-carb diet were more likely to consume more alcoholic beverages. Nevertheless, Dr. Hu and his researchers concluded that there was a statistically higher risk for the various cancer and heart disease deaths as well as all-cause mortality with the animal-based low-carb diet compared to the plant-based one based on a scoring system used in the study.

This study seems to be bleak news for those of us who support plans like the Atkins diet or Protein Power which include copious amounts of fatty meats. But Dr. Hu was quick to point out in the discussion portion of the study that “The low-carbohydrate diet scores were not designed to mimic any particular versions of low-carbohydrate diets available in the popular literature. Therefore, the risk estimates do not directly translate to the assessment of benefit or risk associated with the popular versions of the diet.” Oh really? Well, you wouldn’t know it from the reporting of this new research where the “A” word has been tossed around like a punching bag with the late, great Dr. Robert C. Atkins’ face attached to it! If the researchers put in their study that this wasn’t meant to be a condemnation of specific low-carb diet plans, then why all the scorning of a nutritional plan that has been the saving grace for millions of people? I’ve never understood the outright hatred and disdain that is directed at those of us who choose to include meat (a “real food” the last time I checked) in our diets. While we are making strides, it’s very clear the educational efforts about why meat-based fats and proteins must continue on until people get it.

To their credit, the Annals of Internal Medicine did allow an editorial response to this study by Dr. William Yancy from Duke University entitled “Animal, Vegetable, or…Clinical Trial? . Dr. Yancy has received research grants from the Robert C. Atkins Foundation and has conducted some fantastic research studying high-fat, low-carb diets compared with low-fat diets . In his editorial, Dr. Yancy notes that there have been numerous clinical trials in the past decade showing that high-fat, low-carb diets are as effective for weight loss and health risk factors like blood pressure, cholesterol, and blood sugars as low-fat diets and that this trumped the results of older observational studies that erroneously linked dietary fat with poor health outcomes. He explained that “newer observational studies…have absolved fat (with the exception of trans fat) as a detriment to health” and pointed out that they have instead “implicated refined sugars and starches.” In looking at this new study, Yancy says it’s important to view it in the context of the preponderance of the evidence over the past few years.

In fact, it was Dr. Hu himself who released this NIH-funded observational study in November 2006 published in the The New England Journal of Medicine that found the long-term heart health concerns about low-carb diets were unfounded. What data pool did he draw from for his research? The same one he did for this new one–The Nurses’ Health Study. Of course, he was already leaning towards looking at the veggie-based low-carb diet in that study claiming it produced better outcomes. But this latest release pretty much damns an animal-based low-carb diet from being healthy. Dr. Yancy points out the confusing nature of how the data was interpreted now compared with that 2006 study in his editorial.

The overall response that Dr. Yancy provided to this study was that a large-scale, randomized clinical trial is sorely needed to determine these outcomes before making such broad-based pronouncements that a plant-based low-carb diet is superior to an animal-based one. The cohort study results “did not show a clear dose-response relationship in that there was no a clear progression of risk moving up or down” in comparing the two diets. In other words, Dr. Yancy revealed that many other factors could have been at work aside from the diet, including what I noted earlier regarding the animal-based low-carb dieters being three times more likely to smoke as well as half as likely to exercise. Additionally, any changes in the dietary patterns over time were not included as part of this study.

Plus, in thinking about this observational study, who’s to say the participants ate “low-carb” when they consumed animal-based or even plant-based diets? Claiming someone who eats meat is on an animal-based low-carb diet is the same thing as arguing that completing a “Paint-By-Number” painting makes you the next Vincent Van Gogh. Couldn’t those “animal-based” eaters have consumed lots of lean protein sources like chicken or turkey to make it a low-fat, low-carb diet–not at all like the Atkins diet? After all, these participants are all medical professionals and were undoubtedly telling their patients with weight and health issues to cut the fat in their diet? And mixing that kind of food intake with an unspecified amount of carbohydrate in the diet, it’s virtually impossible to know whether any of these people ever got close to what would be considered the Atkins diet. A total crapshoot!

Dr. Yancy noted that the time for conducting a genuine diet trial is “more feasible today than ever before given the possibility of a ubiquitous health information infrastructure emerging in the United States.” And he’s right! Have you ever stopped to think about how confusing it is for the public to be exposed to seemingly conflicting diet studies? Just last month we saw the Gary Foster study published in this exact same journal touting the cardiovascular health benefits of a high-fat, low-carb diet. That one was a randomized clinical trial while the Hu trial was not. And yet there is no distinction made in the reporting of these two studies to the public as both are given airtime exposure to the public as if these two research methodologies are identical. They are not. This “major detractor,” as Dr. Yancy describes the constant “plethora of mixed messages society receives about what and what not to eat” is merely making dietary truth harder to penetrate our culture. He ends his editorial with a rhetorical question that desperately needs an answer.

Isn’t adherence likely to be higher if we had greater certainty about which dietary patterns are healthy and which are not?

Of course, this teeny tiny little detail didn’t deter the famous low-fat diet guru Dr. Dean Ornish from chiming in on the study in his Huffington Post column (where he serves as the Medical Editor). As I noted at the beginning, the low-fat apologists like Ornish have conceded defeat on the carbohydrate argument and have made it all about the source of the fat now. Ornish admitted as much when he says the “Eco-Atkins” is “essentially the same diet that I have been recommending and studying for more than 30 years” although he has changed many of his views over the years while claiming to have never changed. Most of this article simply regurgitates the same information we’ve heard from Dean Ornish ad nauseam for many years, including what he has previously shared in my two podcast interviews with him in October 2007 and then again in February 2008 (he’s refused to come back on the podcast again ever since). Dr. Ornish claims this new study is “important” because it exposes the flaws of an animal-based diet. But I wonder if our good buddy would be willing to put his money where his mouth is to work in conjunction with researchers like Dr. Eric Westman at Duke and Dr. Jeff Volek at The University of Connecticut for the long-term randomized clinical trial Dr. Yancy talked about? If he’s so hellbent on claiming his diet is superior for “reversing heart disease,” then why not prove it by having his team work with the high-carb, low-fat dieters in the study while Westman and Volek work with the high-fat, low-carb dieters? Until this kind of research is done where compliance by participants in both study groups is virtually mandated, then all of these back-and-forth headlines about which diet is optimal will continue on indefinitely with no practical conclusions to serve the general public. And that’s the greatest shame of all in this entire discussion.

Speaking of Dr. Volek, here’s what he had to say about the Hu study.

“What strikes me about this study is the assumption by the authors that the massive numbers of subjects overcomes the well known limitations associated with using food frequency questionnaires (FFQ). I don’t see a nutritionist or dietitian as an author, so maybe they are unaware that the FFQ method is not quantitative. This is true whether there are 20 subjects or 200,000 subjects in the study. Even if we assume some level of accuracy in assessing carbohydrate and overall nutrient intake by FFQ, these authors only examined food intake at one time point at the start of the 20+ year studies. The conclusions are predicated on the notion that subjects did not change their dietary patterns (an unlikely assumption). If a person decided to change their diet at any point during the two-decade study it would not be reflected in the analysis. In respect to the Atkins Diet, it should be emphasized that using these data as an indictment of the diet as being unhealthy is inappropriate. From the data presented the cohort with the lowest carbohydrate intake had a median carbohydrate intake (% of energy) of 35% (men) and 37% (women), nowhere close to the level of carbohydrate restriction of the Atkins Diet. The benefits of carbohydrate restriction may not be linear (this is open to debate) and the fact there is limited if any data on very low carbohydrate intakes in this cohort indicates the results are irrelevant to true followers of the Atkins Diet.”

The bottom line: these people didn’t do the Atkins diet. So for the media and people like Dean Ornish to label the nutritional intake of these study participants as such is dishonest and you can only conclude was a purposeful act to smear a healthy dietary plan that has been the saving grace in the weight and health of so many Americans. One of my longtime readers named Peter who has often played devil’s advocate with me in debating my interpretations of various diet studies over the years that have been both pro- and anti-low-carb forwarded his preemptive comments about the Hu study that I thought were worth sharing. Here’s what he said:

We know that people who get their food at farmer’s markets and health food stores are different in hundreds of ways from people who get their food from supermarkets and fast food restaurants. If you ever stand in line at Safeway among the mostly overweight people buying sodas and candy or the skinny people at the health food store buying brown rice and vegetables, you can see they are two different groups. Ever see anyone smoke at the farmer’s market? We just don’t know which of the hundred ways that that the health food eaters are more health conscious really make the difference. Mostly we just know what both Ornish and Atkins agreed on, that the sugar and flour diet is a bad idea. We’ll have to wait a while for a really good study before we know that “Atkins Diet Increases All Cause Mortality” or if it doesn’t.

Well said Peter! And as much as I’d love to see that study happen as Taubes noted is necessary at the end of Good Calories, Bad Calories, there’s just too much at stake for low-fat diet apologists to crack open that door even a tiny little bit just in case they’re wrong about high-fat, low-carb diets. Right now they’re sitting pretty by continuing to spread lipophobia to the masses, but time is running out when someday that dog won’t hunt anymore. And when it does, I’ll be happily waiting here to share about the good news of livin’ la vida low-carb. And I’ll say it again: be encouraged my friends because we ARE making a difference! Never stop shining on behalf of the healthy low-carb lifestyle!

Share your feedback about this study by Dr. Frank Hu by sending him an e-mail at frank.hu@channing.harvard.edu . I’ve previously asked him to come on my podcast for an interview, but I never received a response. I’d be very curious to ask him how he can reconcile the stark difference in the conclusions he made in his 2006 study compared with this one four years later. Let me know if you receive a response from Dr. Hu.

Post a comment
Write a comment: