Vegetable Oil and Heart Disease: New news from the way-back machine

Since the 1970’s, we’ve reduced our sugar, salt, and saturated fat intake, and we’ve dramatically reduced our rates of smoking, high serum cholesterol and high blood pressure. At the same time, rates of chronic disease, including coronary heart disease, have increased—in some cases, dramatically.

The best that we can say is that since the 1970s, rates of myocardial infarction have decreased slightly—but only in white folks.

If the current health prescription is valid, then we should see dramatic differences in rates of disease and mortality between those who follow the prescription and those who don’t, and we should see clear and strong associations between “healthy” food choices and good health (because the same people eating a “healthy” diet are also taking care of their health in other ways). Yet this is not what we see.

Is it possible that our low-fat diet has removed some protective factors from our nutritional profile and exposed us to increased levels of nutrients that have negative impacts on health? I think it is, and a recent study in BMJ supports this notion.

I am a long-time admirer of one of the researchers, Daisy Zamora, and she is a good friend of mine. She’d been dropping hints about this great study she was working on for a while now—but was sworn to secrecy and now I know why. What she and her co-investigators have uncovered is data from a long-ago diet study, conducted from 1966-1973. It’s a decently large, well-run, randomized controlled trial that replaces saturated fat with safflower oil, a vegetable oil particularly high in one kind of PUFA—omega-6 (n-6) linoleic acid—and low in another kind of PUFA—omega-3 (n-3) alpha linolenic acid. The idea was that replacing “bad” saturated fat with “healthy” vegetable oil in men with premature coronary heart disease would improve survival. This did not turn out to be the case. For some reason, though, the original study only reported all-cause mortality and not deaths from cardiovascular disease and coronary heart disease.

Daisy and her co-investigators climbed into their way-back machine and this is what they found: Not only did the participants in the intervention group have an increased risk of all-cause mortality, but they had an increased risk of death from cardiovascular disease and coronary heart disease.

The blue line is the safflower oil group; the red line is the control group. To put it rather simplistically, the widening gap between the two groups means the intervention group died a lot faster than the controls.

Although the switch to safflower oil did lower total cholesterol, these reductions didn’t help those participants live any longer than those who kept eating saturated fat. In fact, as the authors note, “the increased risk of death in the intervention group presented fairly rapidly and persisted throughout the trial.”  (Hmm. Maybe this whole “cholesterol lowering” thing isn’t as important as we thought.)

Furthermore, the authors go on to point out that the relationship between linoleic acid consumption and increased mortality was particularly robust in smokers and drinkers, “suggesting that diets high in n-6 [linoleic acid] may be particularly detrimental in the context of oxidative stress induced by smoking and alcohol.”

Everyone knows that if you are a smoker you should quit and that alcohol should be used in moderation. But, with this evidence in mind, if you decided to keep on smoking and/or you want to drink immoderately, you may want to consider a breakfast of eggs and bacon rather than whole wheat toast and “heart healthy” margarine before you do.

The entire article is available online. Read it for yourself and see what you think.  Anybody besides me wondering how the American Heart Association will respond to this study?

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28 thoughts on “Vegetable Oil and Heart Disease: New news from the way-back machine

  1. “In light of the new evidence that has emerged regarding the relationship between dietary fat and heart disease…”

    OR, they could say, “In light of evidence that has existed for about 50 years, but which we chose to ignore in favor of expediency and political correctness…”

    Other than that, your take on what the AHA *could* say is great. It would go a long way toward improving their credibility among the lipid/diet/heart disease skeptics, and maybe even among the American public, too. (I think the idea that fat…even saturated fat…isn’t the pure spawn of the devil is catching on. Seems like more people are buying real butter and eggs these days.) It would also save them the huge, enormous embarrassment they would face if they offered a genuine, no-holds-barred “mea culpa.” The sample statement you gave lets them acknowledge that despite decades of iron-clad recommendations regarding saturated fats, the matter is *not,* in fact settled, but spares them having to come right out and say they might have been wrong–*dead wrong.* (Pun intended.)

    1. In the bigger picture, the anti-saturated fat attitude is embedded in public health policy all about the globe. For example, in Australia, the Heart Foundation’s official response to “Toxic Oil” by David Gillespie was to fall back on consensus of opinion:

      “Good quality consistent evidence demonstrates that omega-6 polyunsaturated fats reduce your ‘bad’ or LDL cholesterol in your blood and increase the ‘good’ HDL cholesterol. This helps to lower your risk of heart disease.

      There is also scientific consensus that replacing saturated fat with unsaturated fat, in particular polyunsaturated fat, reduces your risk of heart disease. This position is supported by the World Health Organisation, other leading International Heart Associations, the CSIRO and the Dietitians Association of Australia (DAA).

      For this reason, the Heart Foundation recommends replacing saturated fat with unsaturated fat as one way to improve your heart health.”
      http://www.heartfoundation.org.au/news-media/Media-Releases-2013/Pages/claims-david-gillespies-toxic-oil.aspx

      Here’s what the late Michael Crichton said about scientific consensus in a 2003 speech delivered to the California Institute of Technology: “I regard consensus science as an extremely pernicious development that ought to be stopped cold in its tracks. Historically, the claim of consensus has been the first refuge of scoundrels; it is a way to avoid debate by claiming that the matter is already settled. Whenever you hear the consensus of scientists agrees on something or other, reach for your wallet, because you’re being had. Let’s be clear: the work of science has nothing whatever to do with consensus. Consensus is the business of politics. Science, on the contrary, requires only one investigator who happens to be right, which means that he or she has results that are verifiable by reference to the real world. In science consensus is irrelevant. What is relevant is reproducible results. The greatest scientists in history are great precisely because they broke with the consensus. There is no such thing as consensus science. If it’s consensus, it isn’t science. If it’s science, it isn’t consensus. Period.”
      Google – PDF Aliens Cause Global Warming

    2. “In light of evidence that has existed for about 50 years, but which we chose to ignore in favor of expediency and political correctness…”

      Yeah–that too!

      I’ve been thinking about this a lot & at this point, I think it would be a start if the AHA & similar organizations would:
      1) acknowledge the controversy and uncertainty in the science, even if they don’t feel that it warrants a shift in position and
      2) they educate the public regarding those controversies and uncertainties

      How much worse does the nation’s health have to get before something changes?

  2. Well, that didn’t work.

    Darcy Sptiz’s email address can be obtained from the “no-change-in-aha-recommendations-on-saturated-or-poly-unsaturated-fat” press release I referenced in my February 19 comment.

  3. The word importune means “to make repeated forceful requests for something, usually in a way that is annoying or causing slight problems.”

    While I try not to be annoying, It seems like a good idea to importune the American Heart Association, but not Darcy Spitz, the AHA’s Senior Communications Manager. So I suggest Adele and those who read her blog send Darcy some of that “Science” that the AHA scientific committee is currently ignoring. Here’s her email address:

    Darcy Spitz

  4. http://en.wikipedia.org/wiki/Lipid_hypothesis

    this article has long featured an “appeal to consensus” in the pro-hypothesis part of its discussion, a poll of scientists from 1978 showing almost all supported the hypothesis and the dietary recommendations.
    is there any other theory where a poll of scientists needed to be be cited in evidence?
    Did they poll scientists before teaching evolution or building the bomb?
    Even the global warming wiki page doesn’t go that far.

    1. As Gary Taubes famously said (and I paraphrase): If you have to have a conference to “develop” consensus, then you don’t have consensus. I’ve got a blog post brewing that digs out some of the details on how the lid really got put on any more discussion of scientific controversy about nutrition.

  5. Not sure how the AHA will manage to dodge this one. A service for physicians, Physicians First Watch, sent the following out today in their regular email notification of important medical/health news for MDs:

    40-Year-Old Data Cast Doubt on Dietary-Fat Guidance
    By Joe Elia
    Data recovered from an old trial confirm the increased risks of substituting dietary omega-6 linoleic acid (n-6 LA) for saturated fats, calling American Heart Association advice into question. The data appear in BMJ.
    Cardiovascular outcome data from the 1966-1973 Sydney Diet Heart Study were analyzed for the first time. The trial, conducted among some 450 men with recent coronary events, tested the effect of replacing dietary saturated fats with n-6 LA. Reports after the end of the trial showed increased all-cause mortality among those receiving n-6 LA. The recovered data, which had been stored on tape, also show increased risks for mortality from cardiovascular disease (hazard ratio, 1.70) and coronary disease (1.74).
    An editorialist writes: “These findings argue against the ‘saturated fat bad, omega-6 [polyunsaturated fatty acid] good’ dogma.”

    Then they provide the link to the full study in the BMJ. Cool!

    1. Thanks for sharing this. I hope the study makes some waves, but I’ve learned to never underestimate the ability of the status quo to plug their ears and say “I can’t hear you!” Remember those quotes that Laura brought back from DC saying “the science is settled”?

  6. “History teaches us that men and nations behave wisely once they have exhausted all other alternatives.” (Abba Eban)

    I light of the fact that, by almost every measure of physical and emotional health, the public health has trended downward ever since the government began recommending low-fat intake, saturated fat restriction, and increased vegetable oil intake, one wonders when desperation will set in and the powers that be will forced to admit their mistake. That the mistake persisted so long suggests that so-called scientific consensus may not be the proper test for truth. The late Michael Crichton shared his views on consensus science in a lecture delivered at Caltech on January 17, 2003.

    “I want to pause here and talk about this notion of consensus, and the rise of what has been called consensus science. I regard consensus science as an extremely pernicious development that ought to be stopped cold in its tracks. Historically, the claim of consensus has been the first refuge of scoundrels; it is a way to avoid debate by claiming that the matter is already settled. Whenever you hear the consensus of scientists agrees on something or other, reach for your wallet, because you’re being had.

    Let’s be clear: the work of science has nothing whatever to do with consensus. Consensus is the business of politics. Science, on the contrary, requires only one investigator who happens to be right, which means that he or she has results that are verifiable by reference to the real world.

    In science consensus is irrelevant. What is relevant is reproducible results. The greatest scientists in history are great precisely because they broke with the consensus. There is no such thing as consensus science. If it’s consensus, it isn’t science. If it’s science, it isn’t consensus. Period.” http://www.s8int.com/crichton.html

    In a review of Review of, Dogmatism in Science and Medicine by Ron Westrum, Henry Bauer said, “The growth of consensus is usually seen as a good development for science; Bauer shows how, on the contrary, that consensus can be forced and illusory. Consensus may instead represent a situation in which other opinions are simply not heard. As Bruno Latour wrote in Science in Action, entrepreneurs in science strive to sell their constructions. If they are successful, however, the temptation to squelch dissent or competition may result in a monopoly.”
    http://social-epistemology.com/2012/10/15/ron-westrum-review-of-henry-bauer-dogmatism-in-science-and-medicine/

    In my view, it is the responsibility and prerogative of political leaders to correct mistakes that damage the public health. Unfortunately, due to ignorance, none of our current representatives and senators are equipped to alter government policy in a direction that would benefit the public health. Perhaps it’s time for knowledgeable health professionals and laypersons to familiarize our leaders, on the local, state, and federal levels, with the particulars.

    1. Great comments. I just got introduced to Bruno Latour (and critical science studies in general) recently, so I really appreciate your adding to my education in this area.

      1. As one of my favorite professors (of critical studies) recently reminded me: “These are life and death issues.” Understandably, it is deeply disturbing to recognize and to acknowledge the full extent of misery and suffering inflicted on human beings when consensus-building and other forms of social control continue to dominate health sciences and science in general. Thank you so much for applying critical analysis to nutrition science and for bringing the field(s) of critical science studies to the attention of your readers. I would really appreciate any reading suggestions that strike you as particularly relevant or helpful for those of us just becoming familiar with critical science studies. Thanks!

  7. “Anybody besides me wondering how the American Heart Association will respond to this study?”

    I expect they won’t. Any more than the responded to the Lyon Diet-Heart Study, which had to be halted because the AHA “Prudent” diet increased cardiac mortality by a similar amount. Stephan Guyenet argued (several years ago) that the key intervention there was reducing linoleic acid intake. Looks like Stephan was spot-on.

    “The Lyon Diet-Heart Study”
    http://wholehealthsource.blogspot.com/2009/06/lyon-diet-heart-study.html

    1. Yeah, I sort of expect deafening silence myself. But if physicians start to pick up on this, we may have a different scenario.

      1. Thanks for passing that along.

        “…an overall healthy dietary pattern that emphasizes fruit, vegetables, high-fiber whole grains, low-fat dairy products, lean meat, poultry and fish,” Kris-Etherton said.”

        Often wrong, never in doubt.

        1. I agree, thanks Dave, for passing that along. And well said, Tuck.

          What bothers me most is the certainty that the science regarding what constitutes “healthy food” is a closed book. It does far more damage than simply limiting the general public’s notion of dietary recommendations to one approach. It also prevents clinicians from questioning the role of diet in disease just as long a person is already following the standard “healthy” one, when in some circumstances, a different diet would bring better health outcomes. It allows policymakers and public health workers to blame the public for “not following” the “healthy diet” rules, and it contributes to a lot of self-blame when people use the status quo approach to health and it doesn’t work for them.

          I’m not prepared to advocate for another dietary paradigm that I think is “best,” but I am ready to advocate for a critical approach to our current one.

          1. The real problem is that the AHA is ignoring the evidence that refutes their recommendations. Their approach to this study is consistent with their approach to Dr. Kraus’s meta-analysis of saturated fat research from a couple of years ago: ignore the meaningful part of the research.

            As the saying goes, you’re entitled to your own opinion, but not to your own facts, AHA.

            1. I get that the AHA is not going to come right out and change their recommendations; different scientist interpret evidence, “facts” if you will, differently, something that has been evident from the beginning of this debacle. But if the AHA were really interested in protecting the health of Americans and not just covering their collective butts in light of the possibility that the advice they’ve been given us for the past 40 years has been at best ineffective and at worst lethal, their PR statement would sound like this: “In light of the new evidence that has emerged regarding the relationship between dietary fat and heart disease, the AHA is committed to critically evaluating its dietary guidance so that Americans may benefit from the best guidance possible.” Instead they simply sound as if it makes no difference what any new science might say, they are not going to change their message.

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