The reporter from Men’s Health asked me: “You finish dinner, even a satisfying low-carb dinner,” — he is a low-carb person himself — “you are sure you ate enough but you are still hungry. What do you do?” I gave him good advice. “Think of a perfectly broiled steak or steamed lobster with butter, some high protein, relatively high fat meal that you usually like. If that doesn’t sound good, you are not hungry. You may want to keep eating. You may want something sweet. You may want to feel something rolling around in your mouth, but you are not hungry. Find something else to do — push-ups are good. If the steak does sound good, you may want to eat. Practically speaking, it’s a good idea to keep hard-boiled eggs, cans of tuna fish around (and, of course, not keep cookies in the house).” I think this is good practical advice. It comes from the satiating effects of protein food sources, or perhaps the non-satiating, or reinforcing effect of carbohydrate. But the more general question is: What is hunger? (more…)
Posts Tagged ‘diabetes’
Tags: ADA, carbohydrate, diabetes, low carbohydrate, nutrition
The joke in academic circles is that there are three responses to a new idea. First, “This is wrong,” second, “There’s nothing new in this,” and third, the sub-title of this post. Priority in a scientific discovery is fundamental in science, however, and “we thought of this first” is not always that funny. Getting “scooped” can have serous practical consequences like jeopardizing your grant renewal and, if nothing else, most of us are motivated by a desire to solve the problem and don’t like the feeling that, by analogy, somebody came along and filled in our crossword puzzle. In dietary carbohydrate, all three of the responses co-exist. While an army of dietitians is still claiming that people with diabetes need ever more carbohydrate, in the background the low-fat paradigm crumbles and, somewhat along the lines of the predictions in A Future History of Diabetes , the old guard are coming forward to tell us that they have been recommending low-carb all along.
The latest discoverer of the need to reduce dietary carbohydrate is David Jenkins whose recent paper is entitled “Nuts as a Replacement for Carbohydrates in the Diabetic Diet.”  The title is crazy enough, following the tradition of getting away from nutrients, that is, well-defined variables, and replacing it with “food,” that is, mixtures of everything. It is, in fact, not really a low carbohydrate study but the experimental design is not the problem. It is the background and rationale for the study which recognizes the disintegration of the low-fat diet paradigm but, at the same time, fails to cite any of the low-carbohydrate studies that have been instrumental in showing the need to replace carbohydrates in the diabetic diet. Given forty years of studies showing the benefits of low carbohydrate diets and forty years of unrestrained attacks on the method, it will be interesting to see how Jenkins shows that it is actually the nutritional establishment that invented carbohydrate restriction.
Disputes over priority are well known in the history of science. Newton’s frequently quoted statement that he had seen farther than others because he had “stood on the shoulders of giants” has been interpreted by some historians as a sarcastic comment aimed at Robert Hooke with whom he had, among other things, a dispute over the priority for the inverse square law (force of gravity varies as the inverse of the square of the distance: F = GmM/g2). Hooke was short and suffered from kyphosis and is assumed not to have shoulders you would profitably stand on.
Even Einstein had trouble. His dispute with the mathematician David Hilbert about priority for the field equations of general relativity (also about gravity) is still going on, a dispute that I prefer to stay out of. Cited by his biographer, Abraham Pais, Einstein had apparently made up the verb to nostracize (nostrazieren) which he accused Hilbert of doing. (He meant that Hilbert had made Einstein’s idea community knowledge. Googling the word gives you only “ostracize” and “Cosa Nostra.”)
It is not the priority dispute, per se — the original low carbohydrate diet is usually attributed to William Banting who published the Letter on Corpulence in 1863, although Brillat-Savarin’s 1825 Physiologie du goût understood the principle. He said that some people were carbophores and admitted to being one himself. It is not just priority but that the people who are now embracing carbohydrate restriction were previously unrestrained in their attacks on the dietary approach and were adamant in denying the strategy to their patients.
David Jenkins: “Nuts.”
In trying to find an appropriate answer to the recent bit of balderdash by the redoubtable Hope Warshaw, Tom Naughton recounted the story of the Battle of the Bulge of WWII. Towards the end of the war, Hitler launched a massive winter attack around the city of Bastogne where, at one point, American Forces were surrounded. When the Germans demanded surrender, the American General, Anthony McAuliffe, sent the one-word reply: “Nuts!” I always thought it was a euphemism and that he actually went “Vice-presidential” as it was called in the last administration, but it turns to have been a common expression with him and he really did write “nuts” which, of course, had to be explained to the German couriers. (There is a “Nuts” Museum in Bastogne commemorating the battle which the Americans won somewhat as described in the movie Patton).
For installation in the Nutritional Nuts Museum and as an example of the current attempts to co-opt carbohydrate restriction, one can hardly beat Jenkins’s recent paper .
Richard:…Who knows not that the gentle duke is dead? ….
King Edward: Who knows not he is dead! Who knows he is?
Queen Elizabeth: All-seeing heaven, what a world is this!
– William Shakespeare, Richard III
The trick is to act as if the point you are making is already established. The Abstract of Jenkins study: “Fat intake, especially monounsaturated fatty acid (MUFA), has been liberalized in diabetic diets to preserve HDL cholesterol and improve glycemic control….” It has? Liberalized by whom? Although the American Diabetes Association guidelines are traditionally all over the place, few would consider that there is any sense of substantial liberalization on replacing carbohydrate with fat from them or any health agency.
“Replacement of carbohydrate by healthy fat … has been increasingly recognized as a possible therapeutic strategy in the treatment of diabetes  as concerns emerge over the impact of refined carbohydrate foods in increasing postprandial glycemia and reducing HDL cholesterol.” Reference  ((1) in the original) actually “emerged” in 2002 and is ambiguous at best: “Carbohydrate and monounsaturated fat together should provide 60–70% of energy intake.” (It is not my style of humor, but the behavioral therapists call this “shoulding on people.”) The paper admits that the evidence “is based on expert consensus” and contains what might be called the theme song of the American Diabetes Association:
“Sucrose and sucrose-containing food do not need to be restricted by people with diabetes based on a concern about aggravating hyperglycemia. However, if sucrose is included in the food/meal plan, it should be substituted for other carbohydrate sources or, if added, be adequately covered with insulin or other glucose-lowering medication.” (my italics)
In fact, one emerging piece of evidence is Jenkins 2008 study comparing a diet high in cereal with a low glycemic index diet . The glycemic index is a measure of the actual effect of dietary glucose on blood glucose. Pioneered by Jenkins and coworkers, a low-GI diet is based on the same rationale as a low-carbohydrate diet, that glycemic and insulin fluctuations pose a metabolic risk but it emphasizes “the type of carbohydrate,” that is, it is a politically correct form of low-carbohydrate diet and as stated in the 2008 study: “We selected a high–cereal fiber diet treatment for its suggested health benefits for the comparison so that the potential value of carbohydrate foods could be emphasized equally for both high–cereal fiber and low–glycemic index interventions.” (my emphasis) The Conclusion of the 24-week study was: “In patients with type 2 diabetes, 6-month treatment with a low–glycemic index diet resulted in moderately lower HbA1c levels compared with a high–cereal fiber diet.” The figure below shows the results for HbA1c and weight loss and just looking at the figures, the results are certainly modest enough.
By coincidence, on almost the same day, Eric Westman’s group published a study that compared a low glycemic index diet with a true low carbohydrate diet . The studies were comparable in duration and number of subjects and a direct comparison shows the potential of low carbohydrate diets:
We thought of this first.
Oddly, neither of these papers are cited in the current study by Jenkins, et al. In fact, according to the paper, the precedents go way back:
“Recently, there has been renewed interest in reducing carbohydrate content in the diet of diabetic patients. In 1994, on the basis of emerging evidence, the American Diabetes Association first suggested the possibility of exchanging dietary carbohydrate for MUFA in dietary recommendations for type 2 diabetes). Although not all studies have shown beneficial effects of MUFAs in diabetes, general interest has persisted, especially in the context of the Mediterranean diet.”
The ADA discovered low carbohydrate diets ? Did my blogpost see it coming, or what? But wait…
“low carbohydrate intakes have also been achieved on the Atkins diet by increasing animal fats and proteins. This influential dietary pattern is reflectedin the relatively lower pre-study carbohydrate intakes of ~ 45% in the current study rather than the 50–60% once recommended.
The researchers in this area might not feel that 45 % carbohydrate has much to do with the Atkins diet but, in any case, it appears not to have been “influential” enough to actually get the studies supporting it cited.
Again: “Fat intake, especially monounsaturated fatty acid (MUFA), has been liberalized…” but “… the exact sources have not been clearly defined. Therefore, we assessed the effect of mixed nut consumption as a source of vegetable fat on serum lipids and HbA1c in type 2 diabetes.” Therefore? Nuts? That’s going to clearly define the type of MUFA? Nuts have all kinds of nutrients. How do we know that it is the MUFA in the nuts? In fact, the real question is whether any benefit would not be due to the reduction in carbohydrate regardless of what it were replaced with. So what was the benefit? The figure above shows the effect on hemoglobin A1C. As described by the authors:
“The full-nut dose reduced HbA1c by two-thirds of the reduction recognized as clinically meaningful by the U.S. Food and Drug Administration (.0.3% absolute HbA1c units) in the development of antihyperglycemic drugs…”
In other words, almost meaningful, and
“the number of participants who achieved an HbA1c concentration of <7% (19 pre-study participants, down to 13 post-study participants) was significantly greater on the nut treatment than on the muffin treatment (20 pre-study participants, remaining at 20 post-study participants…).”
This is some kind of accomplishment but the figure above shows that, in fact, the results were pretty poor. The statistics do show that the “full nut dose” was significantly different from the half-nut dose or the muffin. But is this what you want to know? After all, nobody has an average change in HbA1c. What most of us want to know is the betting odds. If I down all those nuts, what’s the chance that I’ll get better. How many of the people in the full-nut study did better than those in the half-nut study (did the authors not know that this would sound funny?). You can’t tell for sure because this information is buried in the statistics but the overlap of the error bars, highlighted in pink, suggests that not everybody gained anything — in fact, some may have gotten worse.
What kind of benefit is possible in a dietary intervention for people with diabetes? Well, the studies discussed above from Jenkins himself and from Westman show that, with a low-GI diet, it is possible to obtain an average reduction of about 4 %, more than ten times greater than with nuts and with a real low-carbohydrate diet much greater. I have added an inset to the Figure from Jenkins with data from a 2005 study by Yancy, et al. . The red line shows the progress of the mean in Yancy’s studied. If you had diabetes, would you opt for this approach or go for the full-nut dose?
1. Jenkins DJ, Kendall CW, Banach MS, Srichaikul K, Vidgen E, Mitchell S, Parker T, Nishi S, Bashyam B, de Souza R et al: Nuts as a replacement for carbohydrates in the diabetic diet. Diabetes Care 2011, 34(8):1706-1711.
2. Franz MJ, Bantle JP, Beebe CA, Brunzell JD, Chiasson JL, Garg A, Holzmeister LA, Hoogwerf B, Mayer-Davis E, Mooradian AD et al: Evidence-based nutrition principles and recommendations for the treatment and prevention of diabetes and related complications. Diabetes Care 2002, 25(1):148-198.
3. Jenkins DJ, Kendall CW, McKeown-Eyssen G, Josse RG, Silverberg J, Booth GL, Vidgen E, Josse AR, Nguyen TH, Corrigan S et al: Effect of a low-glycemic index or a high-cereal fiber diet on type 2 diabetes: a randomized trial. JAMA 2008, 300(23):2742-2753.
4. Westman EC, Yancy WS, Mavropoulos JC, Marquart M, McDuffie JR: The Effect of a Low-Carbohydrate, Ketogenic Diet Versus a Low-Glycemic Index Diet on Glycemic Control in Type 2 Diabetes Mellitus. Nutr Metab (Lond) 2008, 5(36).
5. Yancy WS, Jr., Foy M, Chalecki AM, Vernon MC, Westman EC: A low-carbohydrate, ketogenic diet to treat type 2 diabetes. Nutr Metab (Lond) 2005, 2:34.
Tags: ADA, carbohydrate, diabetes, dietary guidelines, low carbohydrate, low-fat
Doctor: Therein the patient must minister to himself.
Macbeth: Throw physic [medicine] to the dogs; I’ll none of it.
— William Shakespeare, Macbeth
The epidemic of diabetes, if it can be contained at all, will probably fall to the efforts of the collective voice of patients and individual dedicated physicians. The complete abdication of responsibility by the American Diabetes Association (sugar is okay if you “cover it with insulin”) and by other agencies and individual experts, and the media’s need to keep market share with each day’s meaningless new epidemiologic breakthrough leaves the problem of explanation of the disease and its treatment in the hands of individuals.
Jeff O’Connell’s recently published Sugar Nation provides the most compelling introduction to what diabetes really means to a patient, and the latest edition of Dr. Bernstein’s encyclopedic Diabetes Solution is the state-of-the art treatment from the patient-turned-physician. Although the nutritional establishment has been able to resist these individual efforts — the ADA wouldn’t even accept ads for Dr. Bernstein’s book in the early editions — practicing physicians are primarily interested in their patients and may not know or care what the expert nutritional panels say. You can send your diabetes story to Michael Turchiano (MTurchiano.PVP@gmail.com) and Jimmy Moore (firstname.lastname@example.org) at The Patient’s Voice Project.
The Patient’s Voice Project
The Patient’s Voice Project, which began soliciting input on Friday, is a research study whose results will be presented at the Office of Research Integrity (ORI) conference on Quest for Research Excellence, March 15-16 in Washington, D.C. The conference was originally scheduled for the end of August but there was a conflict with Hurricane Irene.
The Patients Voice Project is an outgrowth of the scheduled talk “Vox Populi,” the text for which is at the end of this post. A major stimulus was also our previous study on the Active Low-Carber Forums, an online support group. The March conference will present a session on “Crisis in Nutrition” that will include the results of the Patient’s Voice Project.
Official Notice from the Scientific Coordinator, Michael Turchiano
The Patient’s Voice Project is an effort to collect first hand accounts of the experience of people with diabetes (type 1 and type 2) with different diets. If you are a person with diabetes and would be willing to share your experiences with diet as a therapy for diabetes, please send information to Michael Turchiano (MTurchiano.PVP@gmail.com) and a copy to Jimmy Moore (email@example.com). Please include details of your diets and duration and whether you are willing to be cited by name in any publication.
It is important to point out that, whereas we think that the benefits of carbohydrate restriction have been greatly under-appreciated and under-recommended, the goal is to find out about people’s experiences:both benefits and limitations of different diets. If you have not had good success with low-carbohydrate diets, it is equally important to share these experiences.
- Indicate if you saw a physician or other health provider, what their attitudes were and whether you would be willing to share medical records.
- We are particularly interested in people who have switched diets and had different outcomes.
- Include any relevant laboratory or medical results that you think are relevant but we are primarily interested in your personal reactions to different diets and interaction with physicians and other health providers.
- Finally, please indicate what factors influenced your choices (physician or nutritionist recommendations, information on popular diets(?) or scientific publications).
Thanks for your help. The Patient’s Voice Project will analyze and publish conclusions in popular and scientific journals.
The Survey of the Active Low-Carber Forums
The Active Low-Carber Forums (ALCF) is an on-line support group that was started in 2000. At the time of our survey (2006), it had 86,000 members and currently has more than 130,000. Our original survey asked members of the forum to complete a 27-item questionnaire and to provide a narrative on any other health issues. Some of the narrative answers included in the published paper were as follows:
“I no longer have diabetes, high blood pressure, sleep apnea, joint pain, back pain and loss of energy.”
“I started low carbing for diabetes. My 3 month blood sugar was 8.9 when diagnosed. It is now 5.4. My doctor is thrilled with my diabetes control and as a side benefit, I lost all that weight!”
”I’m controlling my diabetes without meds or injecting insulin (with an a1c below 5), my lipid profile has improved, I’ve lost weight, I’ve gained both strength and endurance, and I’ve been able to discontinue one of my blood pressure meds.”
”I have much more energy, fewer colds or other health problems. I was able to go completely off oral diabetes medication.”
The survey covered a number of topics. We found that most respondents had the perception that they ate less food than before their low-carb diet, and most felt that the major change in their diet was a large increase in the consumption of green vegetables and a corresponding large decrease in fruit intake.
Physicians Attitudes in the ALCF survey
The Patient’s Voice Project is likely to tell us as much about physicians, or at least their interaction with patients, as about the patients themselves. We found in the ACLF survey that slightly more than half of the people who responded said that they had consulted a physician. We were surprised that about 55 % said that the physician or other health professional was supportive of their diet. Another 30 % or so fit the category of “did not have an opinion but was encouraging after seeing results.” Only 6 % of responders indicated that “they were discouraging even after I showed good results,” which may be a surprising result depending on your feeling about the rationality of doctors vs hostility to the Atkins diet. Perusal of patients’ opinions on diabetes websites, however, suggests that the story on people with diabetes will not be as encouraging.
The Survey on Sources of Information
Given the contentious nature of the debate on diet in diabetes therapy, it is not surprising that a group following a low-carb strategy would not put much stock in official sources. The table below shows the breakdown on sources of information from the ALCF survey. Of the half of respondents who said that they relied on original scientific publications, 20 % felt they had generally inadequate access (important articles were not accessible) whereas 61 % felt that access was adequate and were able to see most articles that they wanted.
Voices of Dissatisfaction.
Posts on the ALCLF itself reinforced the idea that official recommendations were not only a limited source of information but that many were perceived as misleading. Typical posts cited in the paper:
“The ‘health experts’ are telling kids and parents the wrong foods to eat. Until we start beating the ‘health experts’ the kids won’t get any better. If health care costs are soaring and type 2 diabetes and its complications, as are most of these expenses why are we not putting a ‘sin’ tax on high glycemic foods to cut consumption and help pay for these cost? Beat the ‘health experts’ – not the kids!”
While I am not a fan of sin taxes, the dissatisfaction is clear, and…
“Until I researched it three years ago – I thought the most important thing was low fat. So I was eating the hell out of low fat products and my health continued to get worse.”
Similarly, the recent article in Diabetes Health by Hope Warshaw http://bit.ly/mYm2O3 with its bizarre recommendation for people with diabetes to increase their carbohydrate intake elicited a number of statements of dissatisfaction:
“Respectfully, this column is not helpful to diabetics and probably dangerous. I am going on 6 years of eating 30-35 carbs/day. My A1c has been in the “non-diabetic” range ever since I went this route and I feel better than I have in years. I am not an exception among the many folks I know who live a good life on restricted carb diets.”
“…carbohydrates are a very dangerous and should be consumed with caution and knowledge. i had awful lipids and blood sugar control on a low fat/high carb diet. now that i have switched to a lower carb diet – all my numbers are superb. and the diet is easy to follow and very satisfying!”
The Project is intended to bring out the patient’s perspective on diet as therapy in diabetes. The goals are to document people’s experience in finding the right diet. In particular, we are interested in whether switching to a low-carbohydrate diet provided improvement over the recommended diet typical of the ADA. Or not. We are looking for a narrative that can bring out how people make decisions on choosing a diet and sticking with it: the influences of physicians, the media and personal experimentation. Your diabetes story.
Text of Abstract for the Original ORI Conference
Crisis in Nutrition: IV. Vox Populi
Authors: Tom Naughton, Jimmy Moore, Laura Dolson
Objective: Blogs and other social media provide insights into how a growing share of the population views the current state of nutrition science and the official dietary recommendations. We ask what can be learned from online discussions among people who dispute and distrust the official recommendations.
Main points: A growing share of the population no longer trusts the dietary advice offered by private and government health agencies. They believe the supposed benefits of the low-fat, grain-based diets promoted by those agencies are not based on solid science and that benefits of low-carbohydrate diets have been deliberately squelched. The following is typical of comments the authors (whose websites draw a combined 1.5 million visitors monthly) receive daily:
”The medical and pharmaceutical companies have no interest in us becoming healthy through nutrition. It is in their financial interest to keep us where we are so they can sell us medications.”
Similar distrust of the government’s dietary recommendations has been expressed by doctors and academics. The following comments, left by a physician on one of the authors’ blogs, are not unusual:
“You and Denise Minger should collaborate on a book about the shoddy analysis put out by hacks like the Dietary Guidelines Advisory Committee.”
“Sometimes I wonder if people making these statements even took a basic course in biochemistry and physiology.”
Many patients have given up on their health care professionals and turn to Internet sites for advice they trust. This is particularly true of diabetics who find that a low-fat, high-carbohydrate diet is not helping them control their blood glucose. As one woman wrote about her experience with a diabetes center:
“I was so frustrated, I quit going to the center for check ups.”
The data suggest a serious problem in science-community interactions which needs to be explored.
Conclusions & recommendations: Our findings document a large number of such cases pointing to the need for public hearings and or conference. The community is not well served by an establishment that refuses to address its critics from within the general population as well as health professionals.
Tags: ADA, biochemistry, carbohydrate, diabetes, insulin, Jay Leno, pancakes
“Headlines” is one of Jay Leno’s routines on The Tonight Show. While low on production values, it provides amusing typos, odd juxtapositions of text and inappropriate couplings from real notices and newspapers. The headlines are frequently very funny since, like fiction in general, authored comedy has to be plausible. There have been many other versions of the same idea including items in the New Yorker but Jay Leno’s audience rapport adds to the impact. Expert as he is, though, Jay seemed a little off guard when nobody laughed at the headline: “The Diabetes Discussion Group will meet at 10 AM right after the pancake breakfast.” It’s probably generational. After 30 or so years having the American Diabetes Association tell you that sugar is Ok as long as you “cover it with insulin” and that diabetes, a disease of carbohydrate intolerance is best treated by adding carbohydrate and reducing fat, who knows what anybody believes.
One of the headlines on a previous show that did get a laugh said: “To increase gas mileage, drive less.” (If Jay only knew how much we spent to get the USDA committee to come up with the advice that if you want to lose weight, you should eat less).
“.. Have we eaten on the insane root,
That takes the reason prisoner?”
– William Shakespeare, Macbeth.
For tragic humor in the bizarre field of diabetes information, it is really hard to compete. About the same time as the headlines sequence on the Tonight Show, DiabetesHealth an organization and website that is intended to “investigate, inform, inspire” produced an inspiring investigation from the literature. The story is entitled “Maple Syrup – A Sweet Surprise.” You gotta’ read this:
“Meet the latest superfood: maple syrup. Wait a minute…maple syrup? The super-sugary stuff poured on pancakes and waffles and used to glaze hams? That maple syrup? That’s right. Researchers from the University of Rhode Island have discovered that the syrup-produced in the northeastern United States and Canada–contains numerous compounds with real health benefits.”
So how did people with diabetes fare on the maple syrup? Well, there were no people. Or animals. The researchers did not test the effect of consumed maple syrup but only chemically analyzed samples of the stuff.
“‘In our laboratory research, we found that several of these compounds possess anti-oxidant and anti-inflammatory properties, which have been shown to fight cancer, diabetes, and bacterial illnesses,’ said Navindra Seeram, an assistant professor of pharmacognosy (the study of medicines derived from natural sources) at the university and the study’s lead author”
“Pharmacognosy,” incidentally, is the only English word correctly pronounced through the nose. The article indicates that “a paper describing their results will appear in the Journal of Functional Foods. Scientists hope that these discoveries could lead to innovative treatments as the beneficial substances are synthesized to create new kinds of medicine.” The article, however, is nothing if not circumspect:
“You might want to pause for a moment before rushing out and buying jug after jug of Canada’s finest maple syrup, though. It still contains plenty of sugar,…” In fact, by far the major ingredient in maple syrup is sucrose which, again, only has to be “covered” with insulin. So, with all those beneficial compounds, we will need less insulin per gram of sucrose with maple syrup, right? Would Jay Leno have gotten a laugh if the diabetes meeting followed the pancakes and maple syrup breakfast? How about if they were whole grain pancakes?
“If you can look into the seeds of time,
And say which grain will grow, and which will not…”
– William Shakespeare, Macbeth.
Not to be outdone, the American Diabetes Association website offers the lowdown on just how good grain is. Fiber, in general, is so good for you that you should be careful not to snarf it up too fast. As they point out, it is “important that you increase your fiber intake gradually, to prevent stomach irritation, and that you increase your intake of water and other liquids, to prevent constipation.” Doesn’t really sound all that healthy but foods with fiber “have a wealth of nutrition, containing many important vitamins and minerals.” Now, vitamin deficiency has always seemed to me to be the least of our nutritional problems but there’s more: “In fact,” using fact in its non-traditional meaning, fiber “may contain nutrients that haven’t even been discovered yet!” (their exclamation point). Not to belabor all the metaphors here, the ADA, long telling us that people with diabetes deserve to have their carbs, are surely offering pie in the sky.
Tags: biochemistry, d'Jousse, David Streiner, diabetes, egg, Geoffrey Norman, nutritional studies
Stepping back and looking at the recent literature, I am struck with how life is a miracle. How could humans have evolved in the face of threats from red meat, from eggs, even from the dangers of shaving? (If you write about nutrition you have to create a macro that types out “I’m not making this up:” the Caerphilly Study  shows you the dangers of shaving… or is it the dangers of not shaving?). With 28% greater risk of diabetes here, 57 % greater risk of heart disease there how could our ancestors have ever come of child-bearing age? With daily revelations from the Harvard School of Public Health showing the Scylla of saturated fat and the Carybdis of sugar between which our forefathers sailed, it is amazing that we are here.
These studies that the media writes about, are they real? They are certainly based on scientific papers. If the media is not always able to decipher them, reporters do generally talk to the researchers. And the papers must have gone through peer review and yet many actually defy common sense. Can the medical literature have such a high degree of error? Could there be a significant number of medical researchers who are not doing credible science? How can the consumer decide? I am going to try to answer these questions. When people ask questions like “could the literature be wrong?,” the answer is usually “yes” and I will try to explain what’s wrong and how to read the nutritional literature in a practical way. I am going to try to make it simple. It is science, but it is pretty simple science. I am going to illustrate the problem with the example of a paper by Djoussé . But first, a joke.
It was a dumb joke. In my childhood, there was the idea, probably politically incorrect, that Indians, that is, Native Americans, always said “how” as a greeting. The joke was about an Indian with a great memory who is asked what he had for breakfast on New Years day the previous year. He says “eggs.” They are then interrupted by an earthquake or some natural disaster and the interviewer and the Indian don’t meet again for ten years. When they meet, the interviewer says “how.” The Indian answers “scrambled.”
If the interviewer had been an epidemiologist he might have asked if he had developed diabetes. Djoussé, et al.  asked participants about how many eggs they ate and then ten years later, if they developed diabetes it was assumed to be because of the eggs. Is this for real? Do eggs cause changes in your body that accumulate until you develop a disease, a disease that is, after all, primarily one of carbohydrate intolerance? The condition is due either to the inability of the pancreas to produce insulin in response to carbohydrate (type 1) or to impaired response of the body to the insulin produced and a deterioration of the insulin-producing cells of the pancreas (type 2). Common sense says that there is something suspicious about the idea that eggs would play a major role. It is worth trying to understand the methodology and see if there is a something beyond common sense, and whether this is a problem in other studies besides Djoussé’s.
What did the experimenters actually do. First, people were specifically asked “to report how often, on average, they had eaten one egg during the past year,” and “classified each subject into one the following categories of egg consumption: 0, < 1 per week, 1 per week, 2-4 per week, 5-6 per week, and 7+ eggs per week.” They collected this data every two years for ten years. With this baseline data in hand they then followed subjects “from baseline until the first occurrence of a) type 2 diabetes, b) death, or c) censoring date, the date of receipt of the last follow-up questionnaire” which for men was up to 20 years. Thinking back over a year: is there any likelihood that you might not be able to remember whether you had 1 vs. 2 eggs on average during the year? Is there any possibility that some of the men who were diagnosed with diabetes ten years after their report on eggs changed their eating pattern in the course of ten years? Are you eating the same food you ate ten years ago? Quick, how many eggs/week did you eat last year?
Reading a scientific paper: the Golden Rule.
Right off, there is a problem in people reporting what they ate but this is a limitation of many nutritional studies and, while a source of error, it is depends on how you interpret the data. All scientific measurements have error. It is not a matter of ignoring the data but rather not interpreting results beyond measurement. So, here’s how I read a scientific paper. First, I look for the pictures. What? A professor of biochemistry looks for the pictures first? In a scientific paper, of course, they are called figures but it’s not just saving a thousand words. (I get a thousand emails every couple of weeks). It’s about presentation of the data.
The principle is that a scientific paper is supposed to explain. I tell graduate students that if you do an experiment and you don’t explain it well, it is as if you had never done it. I ask students “Describe what you are supposed to do in a scientific seminar or other presentation.” After a while, I say: “No. In one word. What are you supposed to do? One word.” The answer is “teach.” The same is true of a scientific paper. The principle is laid out in what I call the golden rule of scientific papers. It comes from the Book PDQ Statistics by Geoffrery Norman and David Streiner. PDQ stands for Pretty Darned Quick and some of the humor is pretty sophomoric (e.g. it has Convoluted Reasoning or Anti-intellectual Pomposity detectors) but it is an excellent introductory statistics book. Here’s the Golden Rule:
“The important point…is that the onus is on the author to convey to the reader an accurate impression of what the data look like, using graphs or standard measures, before beginning the statistical shenanigans. Any paper that doesn’t do this should be viewed from the outset with considerable suspicion.”
– Norman & Streiner, PDQ Statistics 
In other words: teach. Make it clear. Eye-balling Djoussé, et al., we see that there are no figures. A graph of number of eggs consumed vs number of cases of diabetes is what would be expected of the golden rule. The results, instead are stated in the Abstract of the paper as the following mind-numbing statistics:
“Compared with no egg consumption, multivariable adjusted hazard ratios (95% CI) for type 2 diabetes were 1.09 (0.87-1.37), 1.09 (0.88-1.34), 1.18 (0.95-1.45), 1.46 (1.14-1.86), and 1.58 (1.25-2.01) for consumption of <1, 1, 2-4, 5-6, and 7+ eggs/week, respectively, in men (p for trend <0.0001). Corresponding multivariable hazard ratios (95% CI) for women were 1.06 (0.92-1.22), 0.97 (0.83-1.12), 1.19 (1.03-1.38), 1.18 (0.88-1.58), and 1.77 (1.28-2.43), respectively (p for trend <0.0001).”
What does all this mean. In a future blog, I will interpret these “statistical shenanigans” and explain why what the study really shows is nothing. Zero. Zilch. Zimbabwe. I will explain the terms in these results and what to make of it and ask whether it was justified of the authors to conclude: “These data suggest that high levels of egg consumption (daily) are associated with an increased risk of type 2 diabetes in men and women.”
For the moment, I will just state what the statistics mean because it is worth considering the conclusion as stated by the authors. The meaning of the statistics is that there was no risk of consuming 1 egg/week compared to eating none. Similarly, there was no risk in eating 2-4 eggs/week or 5-6 eggs/week. But when you up your intake to 7 eggs or more per week, that’s it. Now, you are at risk for diabetes. The relative risk is small but there it is. You are now at greater risk.
Since I like pictures, I will try to illustrate this with a modified still from the movie, The Seventh Seal directed by Ingemar Bergman. Very popular in the fifties and sixties, these movies had a captivating if pretentious style: they sometimes seemed to be designed for Woody Allen’s parodies. One of the famous scenes in The Seventh Seal is the protagonist’s chess game with Death. A little PhotoShop and we have a good feel for what happens if you go beyond 5-6 eggs/week.
In a future blog I will explain hazard ratio and the related ideas of odds ratio and relative risk. In the mean time, consider that these mean just what you think, that is, they are betting odds, that is, if you knew the odds at two different black jack tables, and the relative odds were less than 2:1 would you know which to play.
1. Ebrahim S, Smith GD, May M, Yarnell J: Shaving, coronary heart disease, and stroke: the Caerphilly Study. Am J Epidemiol 2003, 157(3):234-238.
2. Djoussé L, Gaziano JM, Buring JE, Lee IM: Egg consumption and risk of type 2 diabetes in men and women. Diabetes Care 2009, 32(2):295-300.
3. Norman GR, Streiner DL: PDQ statistics. 3rd edition. Hamilton, Ont.: B.C. Decker; 2003.