Thursday, February 14, 2013

New Study: Replacing Animal Fat with Vegetable Oil = Death

Ahhh it was a good day today when I read this article... "Study raises questions about dietary fats and heart disease guidance".  Here's the scoop... researchers from the United States and Australia have recovered missing data from an old study from the 1970s.  The study, known as the Sydney Diet Heart Study, was a randomized controlled trial in which the participants were told to replace the saturated fats in their diets with polyunsaturated fats from vegetable oil.  The 458 subjects were all men between ages 30-59 who had recently had a coronary event, defined as either a heart attack or angina (1). 

Why was this data missing?  Who knows.  I can't find a good answer.  But had these results been available in the mid 1970s as they should have been, it may have changed the course of the dietary guidelines on fat intake.

Okay so we had two groups, both groups are coming off of either a heart attack or angina.  Let me break it down right quick...

Group 1:  Control group
  • Given no dietary advice at all
Group 2:  Intervention group, given the following instructions...
  • Reduce dietary saturated fat (animal fats) to under 10% of calories
  • Reduce dietary cholesterol to less than 300 mg/day
  • Increase polyunsaturated fats (from safflower oil) to 15% of calories

The participants' diets were reported through a daily food diary, and they reported to the lab for testing 2-3x per year for several years.  Here are the results for all-cause death, cardiovascular disease, and coronary heart disease...

Here you can see the cumulative death rate over the course of 5 years of follow-up.  The data is essentially the same for all-cause, cardiovascular, and heart disease deaths.  It's also statistically significant and very, very clear.  Those in the intervention group, who reduced their saturated fat and cholesterol intake while increasing their polyunsaturated fat intake, fared worse.  In other words, the people eating more saturated fat and cholesterol lived longer, and they had a lower rate of heart disease.

This shouldn't come as a huge surprise if you're a reader of this here blog.  You know saturated fat is wrongly accused... and that vegetable oils are the devil.  Just further evidence here.  But there's something else that's interesting about this study:  the cholesterol levels.  The data is only available for 1 year of follow up, and I had to make this graph myself for your viewing pleasure.  Check it out...

Sorry about the colors... they're actually the opposite of the graphs above and I hadn't realized it til now!  But the point is that the intervention group in red, the group eating more vegetable oils, lowered their total cholesterol nearly 40 points!!  They ended up at 243.9 mg/dl by the end of the first year.  The control group?  Well they lowered theirs a measly 15 points to 266.5 mg/dl.  Both began at the same level.  (There were no significant differences between groups in triglycerides, body mass index, or systolic or diastolic blood pressure at baseline or during follow-up.)

So based on this, you would assume that the intervention group would be better off, right?  But they weren't.  They died far more often of heart disease than the control group did, and with lower cholesterol!  Lesson #1:  Arbitrarily lowering your cholesterol by any means necessary does not and will not lower your risk of heart disease!!!  Cholesterol is just a semi-accurate risk factor...  it is not the cause.  Therefore I don't necessarily give two shits if your diet lowers your total cholesterol. 

But the worst part of all this?  Replacing saturated animal fats with unsaturated vegetable fats has been a cornerstone of mainstream dietary advice for the past 40 years.  I could cite any number of different sources here, like...
  • The 2010 Dietary Guidelines:  "Americans should replace solid fats with oils." pg. 40 (2)
  • The American Heart Association:  "Replacement of saturated fat and trans fat with monounsaturated fat and polyunsaturated fat might even help lower LDL cholesterol when eaten as part of a healthy diet." (3)
  • The My Plate fats and oils info sheet I was forced to teach to teenagers last semester in my community rotation:  "Replacing saturated fats with unsaturated fats lowers your cholesterol and reduces your risk for heart disease."

I, for one, have had enough of this shit.  It's time this changes, and maybe this is the study to put it over the edge.  Saturated fat isn't killing us.  Vegetable oil is.  Eat real food.  Peace I'm out.


  1. You tell it like it is.
    I reckon we should reprint cookbooks from 1966 Australia as The Heart Healthy Diet.
    It' clinically proven to reduce heart attack and death from all causes compared to the diet the ADA and AHA recommend.

    1. Agreed! Any old cookbook like that would be better in my book!

  2. Wow. Those first few graphs are insane. It'd be interesting to imagine where we'd be today had data like this been proclaimed in the 70s.

    However, I think it's fair to say that I'd probably still be a business major had it been - so thanks Ancel