More on Tierney, Taubes and saturated fat
John Tierney, science blogger for the New York Times, was as taken aback by the abject stupidity hostility of the comments to his recent post on fat in the diet that included a response from Gary Taubes about the Israeli low-carb study as I was in my recent post about his post. He decided to post on the subject again, specifically addressing the comments quibbling with the findings on saturated fat. And he included more feedback from Gary.
What we have to keep in mind here is that nutrition is a science (or at least should be) and science is about generating hypotheses, making predictions from our hypotheses, and then seeing if they hold true. The relevant hypothesis here — i.e., what we’ve believed for the past 30-odd years — is that saturated fat causes heart disease by elevating either total cholesterol or LDL cholesterol, specifically. So our prediction is that the diet with the higher saturated fat content will have a relatively deleterious effect on cholesterol. We do the test; we repeat it a half dozen times in different populations. Each time it fails to confirm our prediction. So maybe the hypothesis is wrong. That seems like a reasonable conclusion. No one is proving anything here — as some of your respondents like to decry — we’re just looking at the evidence and trying to decide which hypotheses it supports and which it tends to refute.
The knee-jerk response — as exemplified by quite a few respondents — is to assume that sometime in the not-too-distant past, maybe the 1960s or 1970s, before this low-fat dogma set in, such trials, or far better trials, were done and found the opposite — that the higher the saturated fat in the diet, the lower the cholesterol and the better the cholesterol profile. Or the higher the saturated fat, the greater the mortality. But that’s simply not the case, as I point out in my book. In fact, I’ve been criticized (by Gina Kolata, among others) for going on and on in the book about all the different studies. But I did so precisely because I didn’t want to be accused of cherry picking the data. (I was anyway, but that’s just the nature of this business.) When Ancel Keys, for instance, reported in the 1950s reported that saturated fats raised total cholesterol, which they did in his studies, he based it on comparisons of butter fat to polyunsaturated oils in studies that lasted only two to nine weeks. (He also reported, curiously enough, that the saturated fats had no significant effect on LDL.)
These latest trials just happen to be the best data we have on the long-term effects of saturated fat in the diet, and the best data we have says that more saturated fat is better than less. It may be true that if we lowered saturated fat further — say to 7 % of all calories as the American Heart Association is now recommending — or total fat down to 10 percent, as Dean Ornish argues, or raised saturated fat to 20 percent of calories, as Keys did, that we’d see a different result, but that’s just another hypothesis. The trials haven’t been done to test it. It’s also hard to imagine why a small decrease in saturated fat would be deleterious, but a larger decrease would be beneficial.
Gary’s full commentary here.
In scrolling through the ever-increasing list of comments to this Tierney post, it appears that there has been an outbreak of good sense. There are still a host of overbearing, know-it-all, self-righteous idiots out there (witness the comments below), but, thankfully, they are in the minority.
Bull. Utter Bull. When will the public stop trying to blame their waistlines on some mythical nutrient (or lack thereof) and realize that food…real actual food that does not come from a box, is the only thing you should eat. Eat Food. Not Much. Mostly Plants. How hard is that to recognize?
I noticed a few regular commenters on this blog had commented there, too. All were in the good sense camp.
I suppose that I shouldn’t be too hard on these commenters who are, I assume, just people out there with opinions based on little knowledge and a lot of prejudice when those who should know better make equally idiotic comments.
Here is Robert Eckel, M.D., former president of the American Heart Association (AHA) and professor of Medicine at the University of Colorado medical school, commenting on this study to Medscape (a site available to physicians only) and rejecting the idea that saturated fats could possibly be harmless (or, God forbid, beneficial). Before you read the comments of this influential physician/scientist, go back and read Gary’s comments (or reread GCBC) about how there is no evidence that saturated fat causes heart disease.
Anything that would endorse the Atkins-type of food-intake pattern would not be something that the AHA would back. Saturated fats raise LDL cholesterol — I don’t think many people would disagree with that. . . . At this point limiting saturated fats is still a position the AHA would claim, and I think that’s consistent with the National Cholesterol Education Program guidelines, the American Diabetes Association, the US Department of Agriculture. I don’t think there is any major professional organization at this point that’s willing to throw in the towel on saturated fats and say they are unimportant.
Uh, earth to Bob, earth to Bob, I think a lot of people who actually bothered to read the scientific literature would disagree that saturated fats do squat in terms of causing heart disease. If all you talk to is other statinators and lipophobes who are willing to believe the worst about fats without a shred of evidence other than these shared conversations, then I guess you could come away with this idea. But not if you read the scientific literature, which I always thought was what scientists did. This example glaringly demonstrates the point Gary made in GCBC when he wrote that nutritional science as practiced today can’t really be called science.
Dr. Eckel does make another strange point that I found intriguing in his diatribe against the findings of this study. He first adopts the Ornish argument that you can’t really call the low-fat diet a low-fat diet because it isn’t low-fat enough to qualify as a real low-fat diet. But Eckels morphs this argument into one that says this diet isn’t really an AHA diet because the AHA changed its dietary guidelines. Said he:
The AHA updated its dietary guidelines in 2005, which are quite different from the diet that’s quoted here. The dietary fat restriction at 30% of calories is no longer part of the AHA guidelines, and the saturated-fat content has been reduced from 10% to 7% and the cholesterol content from 300 to 200 mg/day. I think it’s a little bit unfair to kind of generalize that the AHA, number one, stands for a low-fat diet; that’s no longer the case.
Hmmm. Number one. Unfair to generalize that the AHA stands for a low-fat diet. Please.
And number two? Hold on to your seat. Here’s where it really gets interesting. The number two reason that the low-carb, higher-fat diet shouldn’t be compared to the AHA diet:
And number two, there is some kind of mysterious benefit of being on the Mediterranean and low-carb diets over time that doesn’t necessarily at this point have any explanation.
Jesus wept.
I am not making this up. That is a direct quote. Make of it what you will. I suppose the fact that insulin is a fat-storage hormone and that it decreases on a low-carb diet doesn’t “necessarily…have any explanation” in Dr. Eckel’s world, but I’ll bet that any low-carb newbie could probably set him straight.
Hi Dr. Eades,
I have a questions that isn’t realated to this post but I can’t find a place to mail you directly so here goes.
What are your thoughts on Kefir? I’ve been reading a lot about it and it looks like it’s pretty good stuff.
I feel about Kefir the same as I do about yogurt. It’s okay as long as it’s the plain stuff and not sweetened with a bunch of HFCS. it has some good probiotic value for the gut ad some folic acid. But I don’t eat it myself because I’m not a big fan of fermented dairy products. I would rather eat the cow (or sheep) it comes from.
Where did paleolithic eaters find saturated fat? They found it on the game animals that they hunted. The bison’s hump is basically tallow.
Fatty portions, including the viscera and adipose tissue, were the most desirable portions and were reserved for the chiefs and others first in line for the meat. The lean muscle meat was the poorest and least appealing part of the animal. If possible, the lean meat was commonly fed to animals or thrown away (according to Stefansson, Samuel Hearne, Cabeza de Vaca, Weston Price, who documented aboriginal diets).
In the early springtime, when animals tended to be leaner, there were well-known problems with eating too much protein, and the fatty parts of the animals were even more precious. In these times, hunting was discouraged except in emergencies. Just eating lean meat leads to symptoms including severe fatigue, malaise, susceptibility to infection, etc. Australian Aborigines are known to discard a kangaroo carcass if the animal does not have sufficient fat to make it worth slaughtering.
I aim for 70% of calories from fat, 25% from protein, 5% from carbs. So far, I’ve lost 35 lbs, and my cholesterol numbers are as good as they’ve ever been.
Dr. Eades. Thanks for the feedback. A nutritionist friend of mine had recommended I take a cocktail of l-glutamine, bcaa’s, and a little bit of creatine 2-3x a day centered close to my workouts and first thing when I wake up. It’s what he puts bodybuilders on that are low carbing for competition. He had mentioned the l-leucine as a signaling agent, and had recommend the bcaa’s because they don’t need to be broken down in the liver first to be used, they can basically uptake right into the bloodstream. (I could be paraphrasing/butchering that statement, but it was something to that extent)
It’s interesting you mention the rest, cause I had wondered about that element. I wasn’t sure if the lack of carbs might mean the body needs more time to recover since fat isn’t as an efficient energy source as carbs and it might need for recooperation time.
Thanks again for the feedback. And thanks as always for your hard work, your blog is one of the few I checked eagerly everyday in hope of an update
Regarding the study, the fasting glucose and insulin levels of diabetics for the Mediterranean diet was the only one that improved.
Weight loss was comparable, though there was a slightly more pronounced benefit for women on the Mediterranean diet and this is somewhat significant since weight loss for women is generally more difficult.
Weight control (not getting heavier) was effective across the board so carbohydrates didn’t make anyone fat. The Mediterranean diet had moderate carbohydrates (equal to low-fat) and lowest saturated fat and positively affected glycemic profiles. Since weight loss was about the same, or better for low-carb, decreased body fat was not the cause otherwise low-carb would have done as well, or according to low-carb proponents better, since carbohydrate intake is supposed to be solely (or mostly) responsible for insulin response.
Taubes’ theory rests on carbohydrates that drive insulin levels that he states affects everything else. The Mediterranean Diet yielded the best insulin control and improved insulin sensitivity.
From the study we gather:
- Carbohydrates don’t make people fat so long as people follow some sort of diet plan.
- Calorie restriction for (minimal) weight loss and sustained weight control worked, at least for two years. Long term is still up for debate. The low-carb diet was not calorie restricted but for some reason had the highest dropout rate (25%) which implies that calorie restriction isn’t necessarily the reason people fail to adhere to diet plans.
- It was demonstrated that best insulin control was with a diet including moderate carbohydrates and mindful of saturated fats.
Am I missing something here? The study reported that fasting glucose decreased in the Mediterranean diet but increased in the low fat diet. Low carb does not seem to be mentioned. So we do not know what happened here. The paper goes on to state:
“In contrast, insulin levels (Figure 4E) decreased significantly in participants with diabetes and in those without diabetes in all diet groups, with no significant differences among groups in the amount of decrease.”
It then states:
“Among the participants with diabetes, the decrease in HOMA-IR at 24 months (Figure 4F) was significantly greater in those assigned to the Mediterranean diet than in those assigned to the low-fat diet (2.3 and 0.3, respectively; P=0.02; P=0.04 for the interaction among diabetes and Mediterranean diet and time).”
Again, no mention of the low carb group.
“Among the participants with diabetes, the proportion of glycated hemoglobin at 24 months decreased by 0.4±1.3% in the low-fat group, 0.5±1.1% in the Mediterranean-diet group, and 0.9±0.8% in the low-carbohydrate group. The changes were significant (P<0.05) only in the low-carbohydrate group (P=0.45 for the comparison among groups).
In other words, the improvement in glycated hemoglobin, a key marker that reflects average blood sugar levels over a 2-3 months period was significant only in the low carb group whose carbohydrate intake was in the order to 3 – 4 times what is considered appropriate for diabetics. To me this is much more significant than an improvement in fasting glucose.
Taubes’s position on carbohydrate driving insulin secretion is basic chemistry. It is fact, not ‘Taubes’s theory’.
I agree with you on the glycated hemoglobin.
Unfortunately, it seems that there was as much left out of this paper as there was included.
“I’m not sure I would classify lard as a processed, cooked fat. Lard is simply rendered pork fat just as beef tallow is rendered beef fat. Granted, it is heated in the process, but I don’t think enough so that the fats are structurally changed.”
I think there would be a difference between eating fresh pork ribs or belly and eating lard or bacon or salt pork, because of the processing and additives. Meat breaks down when cooked and stored. Salt-preserved meat promotes scurvy, according to Stefansson. Eating fresh meat free of additives seems like the best choice. It would also be best to cook it minimally, surely not well-done or browned or burnt or blackened. Plus, most of the lard I have seen in stores had BHA/BHT or other preservatives. And about 2/3 of the lard I’ve seen was had a mix of lard and partially hydrogenated lard, which is definitely not ideal. I would get leaf lard, which is a similar type of fat to kidney suet in beef. It’s about 25% more saturated than regular pork fat, 50% saturated vs 40%. So it’s similar to red palm oil.
“Jesus wept.”
That statement is by far the funniest thing I have ever read on a nutrition blog….ever
Thanks for making my day Doc.
Glad you enjoyed it.