Pork Chops

Throwing More Saturated Fat into the Fire

A randomized clinical trial that started more than 50 years ago is inflaming passions about the effects of saturated fats on health. Newly published in the BMJ this week, these data went unpublished for decades. The study, intended to test the hypothesis that replacing saturated fat in the diet with polyunsaturated linoleic acid, would lower cholesterol and reduce the risk of death from cardiovascular disease.

The study found lower cholesterol levels, but no effect on mortality.

Strong responses immediately arose from people invested in the recommendations to limit saturated fats. Harvard’s Walter Willett said the research is “irrelevant to current dietary recommendations.” Frank Hu, who helped formulate the latest Dietary Guidelines for Americans, said:

I don’t think the authors’ strong conclusions are supported by the data.

It’s hard to know what “strong conclusions” Hu was seeing in this paper. The principal conclusion was:

Findings from the Minnesota Coronary Experiment add to growing evidence that incomplete publication has contributed to overestimation of the benefits of replacing saturated fat with vegetable oils rich in linoleic acid.

Lead author Christopher Ramsden put it plainly: “Maybe they [saturated fats] are not as bad as people thought.” That sounds pretty moderate to our ears.

Professor Arne Astrup of the University of Copenhagen provided good perspective:

We should put an end to researching “saturated fat”  as a group – it makes no sense. Saturated fats have different health effects depending on the type of fatty acid that is involved – and depending on what food it is present in the food matrix.

For example, dark chocolate, cheese, and eggs are full of saturated fat, but they are either neutral in relation to cardiovascular disease or even protective.

We are not surprised that media will gravitate to conflict in nutrition and obesity research. But we need more light and less heat in the pursuit of new insight.

Click here for the study and here for more from the New York Times.

Pork Chops, photograph © Christopher Aloi / flickr

Subscribe by email to follow the accumulating evidence and observations that shape our view of health, obesity, and policy.


April 14, 2016

8 Responses to “Throwing More Saturated Fat into the Fire”

  1. April 14, 2016 at 6:20 am, Al Lewis said:

    Science needs to be absolutely settled before the government (or, worse) employers start giving dietary advice. (In the case of employers, the advice often involves fines for non-compliance.)

    Perhaps the guidelines should be negatively based — like here are three things NOT to eat. Eat everything else in moderation.

    It’s also very likely that different foods affect different people differently. That possibility is not allowed for in the guidelines.

    • April 14, 2016 at 7:48 am, Ted said:

      Thanks, Al. Good insight.

  2. April 14, 2016 at 9:20 am, Christine Weithman said:

    i love that your wrote about this Ted. I read the story of how the author dug into old old files and took the time to convert them to modern day computing shows intensity! There could be more data to mine from this study as well. Strong proponents of limiting sat fat will continue to say the study is not relevant and others will make a bigger deal of it. Glad to see you pointing out the sat fat that has a neutral impact or even protective as the data shows. But our modern way of life is not good for long term health or the disease of obesity.

    • April 14, 2016 at 9:30 am, Ted said:

      Thanks, Chris. I think much remains to be learned on this subject. I am frustrated by polarized debates on nutrition science where people don’t listen and learn. It’s wayyyyyy too common in this field.

  3. April 14, 2016 at 9:24 am, Charles Baker said:

    The same advice provided by Professor Astrup’ should be applied to glycemic carbohydrates. A plethora of published data is sufficient to justify rigorous examination of the pharmacokinetic and pharmacodynamic similarities and dissimilarities of glycemic carbohydrates.

  4. April 14, 2016 at 9:41 am, Joe Gitchell said:

    More light, indeed!

    Thanks, Ted.


  5. April 14, 2016 at 10:49 am, Stephen Phillips said:

    I could not get past the fact and confound that researchers were able to tightly regulate the diets of the institutionalized study subjects that were institutionalized in one nursing home and six mental hospitals…hardly representative of the general population at that time and place.

    A lot to do about nothing

    Stephen Phillips
    American Association of Bariatric Counselors