Monday, May 17, 2010

Stupid Fat Study

No this isn't about "stupid fats." It's a stupid study, in my opinion.

I try to give research scientists the benefit of the doubt, because I've done lab research myself, and I know how difficult it can be to get reliable results. It's even more complex today than it was when I was in graduate school.

Nevertheless, I think this study, reported in Science Daily, really takes the cake. The SD title is "High-Fat Meals a No-No for Asthma Patients, Researchers Find."

So what did the researchers do?

They fed two different meals to 40 people with asthma and measured any resulting inflammation. Diet 1 was 1000 calories, 52% fat, and consisted of fast-food burgers and hash brown potatoes. Diet 2 was 200 calories, 13% fat, and consisted of reduced-fat yogurt.

They found that people eating diet 1 had more inflammation. So they concluded that the inflammation was caused by fat!

How can you possibly assign blame when the diets differed in so many ways?

An equally valid headline might have been "High-calorie meals a no-no for asthma patients" or "Hash-brown potatoes a no-no for asthma patients" or "Dairy products good for asthma patients" or "Eating lots of fat in combination with lots of carbohyrate a no-no for asthma patients" or "Hamburger buns a no-no for asthma patients."

Instead, they focused on the one ingredient they probably started out believing would be bad and ignored the rest.

This study was presented at the American Thoracic Society 2o10 conference in New Orleans.

One of the researchers said, "This is the first study to show that a high fat meal increases airway inflammation." No it didn't. It showed that a high-fat, high-calorie, high-carbohydrate, commercial junk-food meal increased airway inflammation.

Unfortunately, headlines are all that many people read and remember. Keep in mind that headlines can be misleading. Before accepting the conclusions in any study you think might be important for you, read as much of the full text as you are able to and then make up your own mind.

We can't depend on other people to inform us correctly. We have to take control ourselves.

2 comments:

  1. I haven't seen the study, but it sounds like the same "stupid" interpretation that goes on with so many studies. They see what they want to see; what maintains the status quo. Big sigh. Thanks for posting about this.

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  2. I'm sad to see that it was performed at one of our Aussie universities. Here is the abstract; the method looks a little more intelligent but they still come to the same absurd conclusions.

    A High Fat, High Energy Food Challenge Induces an Exaggerated Inflammatory Response in Asthma.

    http://ajrccm.atsjournals.org/cgi/reprint/179/1_MeetingAbstracts/A2186.pdf

    "Rationale: Dietary fat has been shown to activate the innate immune response, which is known to contribute to the development or worsening of asthma in some individuals. The aim of this study was to examine the effect of dietary fat on innate immune responses in asthma.
    Methods: Non−obese (BMI <30) subjects with asthma were randomized to receive a high fat/high energy (AHiFHE) (n=8) or low fat/ low energy (ALoFLE) (n=10) food challenge. Non−obese healthy controls (n=10) also underwent a high fat/ high energy (CHiFHE) food challenge. Subjects on the AHiFHE and CHiFHE challenge consumed 200% daily energy requirement in 24 hours, including 50% energy from fat. Subjects on the ALoFLE challenge consumed 75% daily energy requirement in 24 hours, including 20% energy from fat. Clinical assessment and blood samples were collected at 0, 2, 3, 4 and 24 hours. Inflammatory markers, including plasma TNFa, CRP and IL−6, were analysed by high sensitivity ELISAs.
    Results: At 4 hours after the commencement of the food challenges, subjects on the AHiFHE challenge, had a significantly higher increase in plasma CRP concentrations, compared to subjects on both the ALoFLE and CHiFHE challenge (p= 0.021).
    The AHiFHE challenge resulted in a significantly higher increase in plasma TNFa concentration at 3 hours, compared to the ALoFLE challenge (p = 0.034).
    Conclusion: A high fat/ high energy intake causes an exaggerated increase in systemic inflammation in subjects"

    Possibly the full text may make more sense, but I doubt it.

    I don't give scientists the benefit of the doubt; I only give them the benefit of my time to read their paper. If it looks half way intelligent I may give them the benefit of a little more time (actually, sometimes a LOT more time :)) to try to understand it.

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